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90-510: American Petroleum Transport Corporation (American Petroleum Tpt) was an oil shipping company founded in New York City in 1936. Daniel K. Ludwig was President of American Petroleum Transport Corporation. In 1939 American Petroleum Transport Corporation operated eight tanker ships from the Gulf of Mexico to Hatteras, North Carolina . American Petroleum Transport Corporation was active in supporting

180-402: A square wave pattern instead of the normal sine wave , making rapid zero crossings possible and minimizing the effects of the problem. Resistance welding involves the generation of heat by passing current through the resistance caused by the contact between two or more metal surfaces. Small pools of molten metal are formed at the weld area as high current (1,000–100,000 A ) is passed through

270-497: A Russian, Konstantin Khrenov eventually implemented the first underwater electric arc welding. Gas tungsten arc welding , after decades of development, was finally perfected in 1941, and gas metal arc welding followed in 1948, allowing for fast welding of non- ferrous materials but requiring expensive shielding gases. Shielded metal arc welding was developed during the 1950s, using a flux-coated consumable electrode, and it quickly became

360-525: A captain on a passage steamer from South Haven to Chicago for many decades. The senior Daniel and his wife Florabelle separated when young Daniel was 15. Daniel Sr. took the youth to Port Arthur, Texas to live with his grandfather John G. Ludwig. Florabelle Ludwig was left alone in South Haven without any means of support. She remarried Daniel Robert Martin in Vancouver, British Columbia in 1915 and resided in

450-414: A highly concentrated, limited amount of heat, resulting in a small HAZ. Arc welding falls between these two extremes, with the individual processes varying somewhat in heat input. To calculate the heat input for arc welding procedures, the following formula can be used: where Q = heat input ( kJ /mm), V = voltage ( V ), I = current (A), and S = welding speed (mm/min). The efficiency is dependent on

540-409: A highly focused laser beam, while electron beam welding is done in a vacuum and uses an electron beam. Both have a very high energy density, making deep weld penetration possible and minimizing the size of the weld area. Both processes are extremely fast, and are easily automated, making them highly productive. The primary disadvantages are their very high equipment costs (though these are decreasing) and

630-652: A job at a marine engine plant, which sent him to the Pacific Northwest and Alaska. At 19, Ludwig established a freighter business by transporting molasses and lumber around the Great Lakes . There are rumors of his engaging in rum running during the Prohibition era . In the 1930s, he developed a novel approach to financing further expansion, by borrowing the construction cost of tankers and using pre-agreed charters as collateral. His National Bulk Carriers became one of

720-449: A massive pulp paper project, and cleared land to plant two varieties of trees to be harvested for paper. He had a 26-mile railroad constructed, as well as 3,000 miles of trails and roads; the settlements had 30,000 inhabitants by early 1982. To feed all the workers, he raised cattle and planted 15,000 acres in rice. In order to develop this, he essentially built a planned community, Monte Dourado . A slum, Beiradao , arose haphazardly across

810-513: A modest amount of training and can achieve mastery with experience. Weld times are rather slow, since the consumable electrodes must be frequently replaced and because slag, the residue from the flux, must be chipped away after welding. Furthermore, the process is generally limited to welding ferrous materials, though special electrodes have made possible the welding of cast iron , stainless steel, aluminum, and other metals. Gas metal arc welding (GMAW), also known as metal inert gas or MIG welding,

900-447: A suitable torch was developed. At first, oxyfuel welding was one of the more popular welding methods due to its portability and relatively low cost. As the 20th century progressed, however, it fell out of favor for industrial applications. It was largely replaced with arc welding, as advances in metal coverings (known as flux ) were made. Flux covering the electrode primarily shields the base material from impurities, but also stabilizes

990-434: A susceptibility to thermal cracking. Developments in this area include laser-hybrid welding , which uses principles from both laser beam welding and arc welding for even better weld properties, laser cladding , and x-ray welding . Like forge welding (the earliest welding process discovered), some modern welding methods do not involve the melting of the materials being joined. One of the most popular, ultrasonic welding ,

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1080-520: A tungsten electrode but uses plasma gas to make the arc. The arc is more concentrated than the GTAW arc, making transverse control more critical and thus generally restricting the technique to a mechanized process. Because of its stable current, the method can be used on a wider range of material thicknesses than can the GTAW process and it is much faster. It can be applied to all of the same materials as GTAW except magnesium, and automated welding of stainless steel

1170-466: Is a fabrication process that joins materials, usually metals or thermoplastics , primarily by using high temperature to melt the parts together and allow them to cool, causing fusion . Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and solid-state welding processes which bond without melting, such as pressure, cold welding , and diffusion bonding . Metal welding

1260-419: Is a hazardous undertaking and precautions are required to avoid burns , electric shock , vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation . Until the end of the 19th century, the only welding process was forge welding , which blacksmiths had used for millennia to join iron and steel by heating and hammering. Arc welding and oxy-fuel welding were among

1350-427: Is a highly productive, single-pass welding process for thicker materials between 1 inch (25 mm) and 12 inches (300 mm) in a vertical or close to vertical position. To supply the electrical power necessary for arc welding processes, a variety of different power supplies can be used. The most common welding power supplies are constant current power supplies and constant voltage power supplies. In arc welding,

1440-469: Is a ring surrounding the weld in which the temperature of the welding process, combined with the stresses of uneven heating and cooling, alters the heat-treatment properties of the alloy. The effects of welding on the material surrounding the weld can be detrimental—depending on the materials used and the heat input of the welding process used, the HAZ can be of varying size and strength. The thermal diffusivity of

1530-430: Is a semi-automatic or automatic process that uses a continuous wire feed as an electrode and an inert or semi-inert gas mixture to protect the weld from contamination. Since the electrode is continuous, welding speeds are greater for GMAW than for SMAW. A related process, flux-cored arc welding (FCAW), uses similar equipment but uses wire consisting of a steel electrode surrounding a powder fill material. This cored wire

1620-433: Is allowed to cool, and then another weld is performed on top of it. This allows for the welding of thick sections arranged in a single-V preparation joint, for example. After welding, a number of distinct regions can be identified in the weld area. The weld itself is called the fusion zone—more specifically, it is where the filler metal was laid during the welding process. The properties of the fusion zone depend primarily on

1710-442: Is characterized by a stable arc and high-quality welds, but it requires significant operator skill and can only be accomplished at relatively low speeds. GTAW can be used on nearly all weldable metals, though it is most often applied to stainless steel and light metals. It is often used when quality welds are extremely important, such as in bicycle , aircraft and naval applications. A related process, plasma arc welding, also uses

1800-407: Is commonly used for making electrical connections out of aluminum or copper, and it is also a very common polymer welding process. Another common process, explosion welding , involves the joining of materials by pushing them together under extremely high pressure. The energy from the impact plasticizes the materials, forming a weld, even though only a limited amount of heat is generated. The process

1890-627: Is commonly used for welding dissimilar materials, including bonding aluminum to carbon steel in ship hulls and stainless steel or titanium to carbon steel in petrochemical pressure vessels. Other solid-state welding processes include friction welding (including friction stir welding and friction stir spot welding ), magnetic pulse welding , co-extrusion welding, cold welding , diffusion bonding , exothermic welding , high frequency welding , hot pressure welding, induction welding , and roll bonding . Welds can be geometrically prepared in many different ways. The five basic types of weld joints are

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1980-413: Is distinct from lower temperature bonding techniques such as brazing and soldering , which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool ) that cools to form a joint that can be stronger than

2070-484: Is made of filler material (typical steel) and is covered with a flux that protects the weld area from oxidation and contamination by producing carbon dioxide (CO 2 ) gas during the welding process. The electrode core itself acts as filler material, making a separate filler unnecessary. The process is versatile and can be performed with relatively inexpensive equipment, making it well suited to shop jobs and field work. An operator can become reasonably proficient with

2160-433: Is more expensive than the standard solid wire and can generate fumes and/or slag, but it permits even higher welding speed and greater metal penetration. Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding, is a manual welding process that uses a non-consumable tungsten electrode, an inert or semi-inert gas mixture, and a separate filler material. Especially useful for welding thin materials, this method

2250-420: Is obtained by a metallic or chemical bond that is formed between the constituent atoms. Chemical bonds can be grouped into two types consisting of ionic and covalent . To form an ionic bond, either a valence or bonding electron separates from one atom and becomes attached to another atom to form oppositely charged ions . The bonding in the static position is when the ions occupy an equilibrium position where

2340-430: Is one important application of the process. A variation of the process is plasma cutting , an efficient steel cutting process. Submerged arc welding (SAW) is a high-productivity welding method in which the arc is struck beneath a covering layer of flux. This increases arc quality since contaminants in the atmosphere are blocked by the flux. The slag that forms on the weld generally comes off by itself, and combined with

2430-692: Is related to the Old Swedish word valla , meaning 'to boil', which could refer to joining metals, as in valla järn (literally "to boil iron"). Sweden was a large exporter of iron during the Middle Ages , so the word may have entered English from the Swedish iron trade, or may have been imported with the thousands of Viking settlements that arrived in England before and during the Viking Age , as more than half of

2520-400: Is sometimes protected by some type of inert or semi- inert gas , known as a shielding gas, and filler material is sometimes used as well. One of the most common types of arc welding is shielded metal arc welding (SMAW); it is also known as manual metal arc welding (MMAW) or stick welding. Electric current is used to strike an arc between the base material and consumable electrode rod, which

2610-438: Is still widely used for welding pipes and tubes, as well as repair work. The equipment is relatively inexpensive and simple, generally employing the combustion of acetylene in oxygen to produce a welding flame temperature of about 3100 °C (5600 °F). The flame, since it is less concentrated than an electric arc, causes slower weld cooling, which can lead to greater residual stresses and weld distortion, though it eases

2700-470: Is used to connect thin sheets or wires made of metal or thermoplastic by vibrating them at high frequency and under high pressure. The equipment and methods involved are similar to that of resistance welding, but instead of electric current, vibration provides energy input. When welding metals, the vibrations are introduced horizontally, and the materials are not melted; with plastics, which should have similar melting temperatures, vertically. Ultrasonic welding

2790-684: The Massachusetts Institute of Technology , Memorial Sloan Kettering Cancer Center , Stanford University and the University of Chicago ). To date, they have received US$ 900 million from the Virginia and Daniel K. Ludwig Fund for Cancer Research. The Centers and the Ludwig Institute are now collectively known as Ludwig Cancer Research . By the terms of the grant, their directors and scientists are to work collaboratively with each other and with

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2880-673: The World War II efforts. Some tanker ships American Petroleum Transport Corporation operated were sunk by German U-boat submarines . Daniel K. Ludwig founded in 1936 the company National Bulk Carriers . American Petroleum Transport Corporation ships were used to help the World War II effort. During World War II American Petroleum Transport Corporation operated Merchant navy ships for the United States Shipping Board . During World War II American Petroleum Transport Corporation

2970-456: The 1590 version this was changed to " ...thei shullen welle togidere her swerdes in-to scharris... " (they shall weld together their swords into plowshares), suggesting this particular use of the word probably became popular in English sometime between these periods. The Old English word for welding iron was samod ('to bring together') or samodwellung ('to bring together hot'). The word

3060-421: The 1930s and then during World War II. In 1930, the first all-welded merchant vessel, M/S Carolinian , was launched. During the middle of the century, many new welding methods were invented. In 1930, Kyle Taylor was responsible for the release of stud welding , which soon became popular in shipbuilding and construction. Submerged arc welding was invented the same year and continues to be popular today. In 1932

3150-587: The Institute. In Canada Rodrigue Choquette, alias Roddy Choquette, was one of his finance advisor. Ludwig married Gladys Madeline Ludwig (1904–1978), in Florida on October 29, 1928. She gave birth to her daughter Patricia Margaret born on October 8, 1936. Estranged from his wife, Ludwig did not acknowledge the girl as his daughter. The couple divorced in April 1937. Believing Patricia might at some later time try to challenge

3240-560: The Soviet scientist N. F. Kazakov proposed the diffusion bonding method. Other recent developments in welding include the 1958 breakthrough of electron beam welding, making deep and narrow welding possible through the concentrated heat source. Following the invention of the laser in 1960, laser beam welding debuted several decades later, and has proved to be especially useful in high-speed, automated welding. Magnetic pulse welding (MPW) has been industrially used since 1967. Friction stir welding

3330-571: The Xanadu Princess in 1973, and lived there for the last two years of his life. In 1954, on a trip to Baja California Sur , Ludwig founded Exportadora de Sal S.A. , which became the "Largest Salt Company in the World", at the Guerrero Negro lagoon. As the rural area was largely uninhabited, Ludwig arranged for the necessary workers and materials to be transported there to build a large, new town in

3420-469: The arc and can add alloying components to the weld metal. World War I caused a major surge in the use of welding, with the various military powers attempting to determine which of the several new welding processes would be best. The British primarily used arc welding, even constructing a ship, the "Fullagar" with an entirely welded hull. Arc welding was first applied to aircraft during the war as well, as some German airplane fuselages were constructed using

3510-437: The atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen , argon , and helium as welding atmospheres. During the following decade, further advances allowed for the welding of reactive metals like aluminum and magnesium . This in conjunction with developments in automatic welding, alternating current, and fluxes fed a major expansion of arc welding during

3600-433: The base material plays a large role—if the diffusivity is high, the material cooling rate is high and the HAZ is relatively small. Conversely, a low diffusivity leads to slower cooling and a larger HAZ. The amount of heat injected by the welding process plays an important role as well, as processes like oxyacetylene welding have an unconcentrated heat input and increase the size of the HAZ. Processes like laser beam welding give

3690-486: The base material. Welding also requires a form of shield to protect the filler metals or melted metals from being contaminated or oxidized . Many different energy sources can be used for welding, including a gas flame (chemical), an electric arc (electrical), a laser , an electron beam , friction , and ultrasound . While often an industrial process, welding may be performed in many different environments, including in open air, under water , and in outer space . Welding

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3780-415: The brothels of Beiradao. The government cooperated in approving a hydropower project which Ludwig had sought, and even the slum was improved, as well as renamed to Laranjal do Jari . Ludwig had the right vision about the need for paper, but was ahead of his time and too late in his life to see the project through to its current success. Beginning in 1971, Ludwig sold off many of his foreign interests, using

3870-402: The butt joint, lap joint, corner joint, edge joint, and T-joint (a variant of this last is the cruciform joint ). Other variations exist as well—for example, double-V preparation joints are characterized by the two pieces of material each tapering to a single center point at one-half their height. Single-U and double-U preparation joints are also fairly common—instead of having straight edges like

3960-726: The construction and use of the new oil supertankers . Ludwig diversified into a wide range of holdings: an oil refinery, banking , cattle ranching , insurance , and real estate . He invested in various mining and exploration projects on nearly every continent: the Americas, Africa, Australia and the Middle East. He created a chain of luxury hotels in Mexico, Bermuda and the Bahamas, and developed Westlake Village, California . At his peak, he owned more than 200 companies in 50 countries, and his fortune

4050-518: The distance between the wire and the base material is quickly rectified by a large change in current. For example, if the wire and the base material get too close, the current will rapidly increase, which in turn causes the heat to increase and the tip of the wire to melt, returning it to its original separation distance. The type of current used plays an important role in arc welding. Consumable electrode processes such as shielded metal arc welding and gas metal arc welding generally use direct current, but

4140-443: The durability of many designs increases significantly. Most solids used are engineering materials consisting of crystalline solids in which the atoms or ions are arranged in a repetitive geometric pattern which is known as a lattice structure . The only exception is material that is made from glass which is a combination of a supercooled liquid and polymers which are aggregates of large organic molecules. Crystalline solids cohesion

4230-600: The electrode can be charged either positively or negatively. In welding, the positively charged anode will have a greater heat concentration, and as a result, changing the polarity of the electrode affects weld properties. If the electrode is positively charged, the base metal will be hotter, increasing weld penetration and welding speed. Alternatively, a negatively charged electrode results in more shallow welds. Non-consumable electrode processes, such as gas tungsten arc welding, can use either type of direct current, as well as alternating current. However, with direct current, because

4320-442: The electrode only creates the arc and does not provide filler material, a positively charged electrode causes shallow welds, while a negatively charged electrode makes deeper welds. Alternating current rapidly moves between these two, resulting in medium-penetration welds. One disadvantage of AC, the fact that the arc must be re-ignited after every zero crossings, has been addressed with the invention of special power units that produce

4410-404: The electrode perfectly steady, and as a result, the arc length and thus voltage tend to fluctuate. Constant voltage power supplies hold the voltage constant and vary the current, and as a result, are most often used for automated welding processes such as gas metal arc welding, flux-cored arc welding, and submerged arc welding. In these processes, arc length is kept constant, since any fluctuation in

4500-438: The filler metal used, and its compatibility with the base materials. It is surrounded by the heat-affected zone , the area that had its microstructure and properties altered by the weld. These properties depend on the base material's behavior when subjected to heat. The metal in this area is often weaker than both the base material and the fusion zone, and is also where residual stresses are found. Many distinct factors influence

4590-613: The first processes to develop late in the century, and electric resistance welding followed soon after. Welding technology advanced quickly during the early 20th century, as world wars drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding , now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding , submerged arc welding , flux-cored arc welding and electroslag welding . Developments continued with

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4680-470: The funds to endow the Ludwig Institute for Cancer Research, which he founded in Switzerland. It became his primary interest in his later years. Since his death in 1992, it has distributed over a billion dollars around the world for cancer research. Under the terms of his will, Ludwig Centers were established in 2006 at six United States research institutions ( Johns Hopkins University , Harvard University ,

4770-526: The government, and announced failing health as a reason to sell his interests. Le Monde described Ludwig with his Jari project as ahead of his time. It reported that in the 21st century a Brazilian consortium bought the Jari complex. Eucalyptus and Australian pine trees were planted that are better suited to the region. New Finnish machinery and technology has drastically reduced the required labor force and, as Le Monde noted, machines neither strike nor go to

4860-423: The interior of Panama to develop for citrus cultivation. He had all the land cleared and built roads and bridges. He had 800,000 Valencia orange trees planted, with full production expected by 1967. It was considered the largest privately owned venture of its kind in the world. Years later it was nationalized. The New York Times reported that an auction of Citricos de Chiriqui, SA failed to attract any bidders;

4950-575: The invention of laser beam welding , electron beam welding , magnetic pulse welding , and friction stir welding in the latter half of the century. Today, as the science continues to advance, robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality. The term weld is derived from the Middle English verb well ( wæll ; plural/present tense: wælle ) or welling ( wællen ), meaning 'to heat' (to

5040-531: The invention of metal electrodes in the late 1800s by a Russian, Nikolai Slavyanov (1888), and an American, C. L. Coffin (1890). Around 1900, A. P. Strohmenger released a coated metal electrode in Britain , which gave a more stable arc. In 1905, Russian scientist Vladimir Mitkevich proposed using a three-phase electric arc for welding. Alternating current welding was invented by C. J. Holslag in 1919, but did not become popular for another decade. Resistance welding

5130-462: The largest American shipping companies, and he eventually owned about 60 vessels. In the 1940s, one of his shipyards in Virginia developed a method to use welding instead of riveting , which saved time during World War II , when there was huge demand for new ships. After the war, he had ships built in Japan, where labor costs were lower. His ships transported oil around the world; in the 1950s he pioneered

5220-412: The length of the arc is directly related to the voltage, and the amount of heat input is related to the current. Constant current power supplies are most often used for manual welding processes such as gas tungsten arc welding and shielded metal arc welding, because they maintain a relatively constant current even as the voltage varies. This is important because in manual welding, it can be difficult to hold

5310-532: The material may not have the ability to withstand the stress and could cause cracking, one method the control these stress would be to control the heating and cooling rate, such as pre-heating and post- heating The durability and life of dynamically loaded, welded steel structures is determined in many cases by the welds, in particular the weld transitions. Through selective treatment of the transitions by grinding (abrasive cutting) , shot peening , High-frequency impact treatment , Ultrasonic impact treatment , etc.

5400-699: The maximum temperature possible); 'to bring to a boil'. The modern word was probably derived from the past-tense participle welled ( wællende ), with the addition of d for this purpose being common in the Germanic languages of the Angles and Saxons . It was first recorded in English in 1590. A fourteenth century translation of the Christian Bible into English by John Wycliffe translates Isaiah 2:4 as " ...thei shul bete togidere their swerdes into shares... " (they shall beat together their swords into plowshares). In

5490-426: The metal. In general, resistance welding methods are efficient and cause little pollution, but their applications are somewhat limited and the equipment cost can be high. Spot welding is a popular resistance welding method used to join overlapping metal sheets of up to 3 mm thick. Two electrodes are simultaneously used to clamp the metal sheets together and to pass current through the sheets. The advantages of

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5580-697: The method include efficient energy use , limited workpiece deformation, high production rates, easy automation, and no required filler materials. Weld strength is significantly lower than with other welding methods, making the process suitable for only certain applications. It is used extensively in the automotive industry—ordinary cars can have several thousand spot welds made by industrial robots . A specialized process called shot welding , can be used to spot weld stainless steel. Like spot welding, seam welding relies on two electrodes to apply pressure and current to join metal sheets. However, instead of pointed electrodes, wheel-shaped electrodes roll along and often feed

5670-620: The minimum asking price was $ 13.9 million. It was later purchased by Colombian businessman, Guillermo Cardenas P., and is still functioning to date. In 1966 Ludwig became attracted to ideas of development in the Amazonian Basin. A brutal military dictatorship had toppled the progressive Goulart government in a 1964 coup , with US backing, and US investment was encouraged by the conservative Brazilian generals in power. In 1967, he purchased about 4 million acres (1.6 million ha) of land in Brazil on

5760-629: The most common English words in everyday use are Scandinavian in origin. The history of joining metals goes back several millennia. The earliest examples of this come from the Bronze and Iron Ages in Europe and the Middle East . The ancient Greek historian Herodotus states in The Histories of the 5th century BC that Glaucus of Chios "was the man who single-handedly invented iron welding". Forge welding

5850-415: The most popular metal arc welding process. In 1957, the flux-cored arc welding process debuted, in which the self-shielded wire electrode could be used with automatic equipment, resulting in greatly increased welding speeds, and that same year, plasma arc welding was invented by Robert Gage. Electroslag welding was introduced in 1958, and it was followed by its cousin, electrogas welding , in 1961. In 1953,

5940-723: The municipality of Mulegé . Here, the saltworks were established by pumping the brine to the surface and allowing it to dry. In 1973, with rumors that the Mexican Government would nationalize the company, Ludwig sold his interest in Exportadora de Sal, SA to Mitsubishi . It owns 49%, with the Mexican government holding the controlling interest. In a $ 25 million 1960 project in Panama , Ludwig bought 10,000 acres (4,000 ha) of land in Dolega , in

6030-472: The north bank of the river in the northeast interior for $ 3 million. He planned to construct a pulp paper factory, known as the Jari project , as he projected a shortage of fiber on the world market in the coming decades (about which he was right). The site was downriver from American Henry Ford 's failed massive project to produce rubber, for which he built a workers' city in the jungle, Fordlandia . Ludwig planned

6120-436: The process, and the industry continued to grow during the following centuries. In 1800, Sir Humphry Davy discovered the short-pulse electrical arc and presented his results in 1801. In 1802, Russian scientist Vasily Petrov created the continuous electric arc, and subsequently published "News of Galvanic-Voltaic Experiments" in 1803, in which he described experiments carried out in 1802. Of great importance in this work

6210-542: The process. Also noteworthy is the first welded road bridge in the world, the Maurzyce Bridge in Poland (1928). During the 1920s, significant advances were made in welding technology, including the introduction of automatic welding in 1920, in which electrode wire was fed continuously. Shielding gas became a subject receiving much attention, as scientists attempted to protect welds from the effects of oxygen and nitrogen in

6300-442: The quality of welding procedure specification , how to judge the skill of the person performing the weld, and how to ensure the quality of a welding job. Methods such as visual inspection , radiography , ultrasonic testing , phased-array ultrasonics , dye penetrant inspection , magnetic particle inspection , or industrial computed tomography can help with detection and analysis of certain defects. The heat-affected zone (HAZ)

6390-650: The quality of a weld, either destructive or nondestructive testing methods are commonly used to verify that welds are free of defects, have acceptable levels of residual stresses and distortion, and have acceptable heat-affected zone (HAZ) properties. Types of welding defects include cracks, distortion, gas inclusions (porosity), non-metallic inclusions, lack of fusion, incomplete penetration, lamellar tearing, and undercutting. The metalworking industry has instituted codes and specifications to guide welders , weld inspectors , engineers , managers, and property owners in proper welding technique, design of welds, how to judge

6480-428: The resulting force between them is zero. When the ions are exerted in tension force, the inter-ionic spacing increases creating an electrostatic attractive force, while a repulsing force under compressive force between the atomic nuclei is dominant. Covalent bonding takes place when one of the constituent atoms loses one or more electrons, with the other atom gaining the electrons, resulting in an electron cloud that

6570-733: The river from Ludwig's development. Ultimately his agricultural ventures on that land were not successful. Neither the rice nor one variety of trees took well to the region's soil. But in 1978 he had a plant shipped by sea in two parts from where it was fabricated in Japan: these were "two behemoths 70 meters high, unique in the history of the merchant navy." The plant was assembled and beginning in February 1979, Jari produced 750 tons of cellulose per day. Losses of $ 1 billion and mounting criticism of his business practices led Ludwig to sell out to Brazilian investors in 1981. He had pushed for more cooperation from

6660-667: The single-V and double-V preparation joints, they are curved, forming the shape of a U. Lap joints are also commonly more than two pieces thick—depending on the process used and the thickness of the material, many pieces can be welded together in a lap joint geometry. Many welding processes require the use of a particular joint design; for example, resistance spot welding, laser beam welding, and electron beam welding are most frequently performed on lap joints. Other welding methods, like shielded metal arc welding, are extremely versatile and can weld virtually any type of joint. Some processes can also be used to make multipass welds, in which one weld

6750-651: The state of Washington the rest of her life. Daniel Sr. moved to Virginia and remarried Isabel Rutherford. Daniel Sr. died in Manatee, Florida in 1960. Ludwig's first venture into shipping was at the age of nine, when he salvaged a 26-foot (8 m) boat. He left school at the end of eighth grade to work in various shipping-related jobs on Lake Michigan and in Texas, directly learning such trades as machinist , marine engineer , and ship handler. In Port Arthur, he sold supplies to sailing ships and steamers. He returned to Michigan to take

6840-604: The strength of welds and the material around them, including the welding method, the amount and concentration of energy input, the weldability of the base material, filler material, and flux material, the design of the joint, and the interactions between all these factors. For example, the factor of welding position influences weld quality, that welding codes & specifications may require testing—both welding procedures and welders—using specified welding positions: 1G (flat), 2G (horizontal), 3G (vertical), 4G (overhead), 5G (horizontal fixed pipe), or 6G (inclined fixed pipe). To test

6930-406: The terms of his will and claim part of his estate, Daniel Ludwig had blood samples frozen in the 1970s that could be used for genetic testing if ever necessary. Patricia Ludwig did file a lawsuit in the 1990s after his death, but DNA analysis proved Ludwig was not her father, and the case was dismissed. Katherine Jones, Patricia's aunt, claimed that everyone in the family thought that Patricia's father

7020-468: The use of a continuous wire feed, the weld deposition rate is high. Working conditions are much improved over other arc welding processes, since the flux hides the arc and almost no smoke is produced. The process is commonly used in industry, especially for large products and in the manufacture of welded pressure vessels. Other arc welding processes include atomic hydrogen welding , electroslag welding (ESW), electrogas welding , and stud arc welding . ESW

7110-415: The welding of high alloy steels. A similar process, generally called oxyfuel cutting, is used to cut metals. These processes use a welding power supply to create and maintain an electric arc between an electrode and the base material to melt metals at the welding point. They can use either direct current (DC) or alternating current (AC), and consumable or non-consumable electrodes . The welding region

7200-420: The welding process used, with shielded metal arc welding having a value of 0.75, gas metal arc welding and submerged arc welding, 0.9, and gas tungsten arc welding, 0.8. Methods of alleviating the stresses and brittleness created in the HAZ include stress relieving and tempering . One major defect concerning the HAZ would be cracking at the toes , due to the rapid expansion (heating) and contraction (cooling)

7290-585: The workpiece, making it possible to make long continuous welds. In the past, this process was used in the manufacture of beverage cans, but now its uses are more limited. Other resistance welding methods include butt welding , flash welding , projection welding , and upset welding . Energy beam welding methods, namely laser beam welding and electron beam welding , are relatively new processes that have become quite popular in high production applications. The two processes are quite similar, differing most notably in their source of power. Laser beam welding employs

7380-518: Was James Sullivan, a sales rep who died in a car accident in 1939 Several months after his divorce, Ludwig married Gertrude Virginia "Ginger" Higgins (January 13, 1897 – April 8, 1993), a widow with three children from a previous marriage. They lived in the penthouse at the Park Cinq , a co-op in Manhattan, and remained married until his death there on August 27, 1992. Welding Welding

7470-520: Was active with charter shipping with the Maritime Commission and War Shipping Administration . American Petroleum Transport Corporation operated Liberty ships and T2 tankers for the merchant navy . The ship was run by its American Petroleum Transport Corporation crew and the US Navy supplied United States Navy Armed Guards to man the deck guns and radio. Daniel K. Ludwig Though he

7560-415: Was also developed during the final decades of the 19th century, with the first patents going to Elihu Thomson in 1885, who produced further advances over the next 15 years. Thermite welding was invented in 1893, and around that time another process, oxyfuel welding , became well established. Acetylene was discovered in 1836 by Edmund Davy , but its use was not practical in welding until about 1900, when

7650-593: Was born in 1897 to Daniel Franklin Ludwig (1873–1960) and Florabelle Leslie (1876–1961) in South Haven, Michigan , on the shores of Lake Michigan . His grandfather, John G. Ludwig (1842–1920), was one of seven brothers in a family of 13, most of them born in Pennsylvania. Four of Daniel's granduncles made their living as captains of Great Lakes vessels. His grandfather's brother, Lancaster Columbus Ludwig (1855–1954), served as

7740-1055: Was estimated at $ 4.5 billion. Ludwig built or bought an impressive collection of hotels. These were: the Hamilton Princess and Southampton Princess in Bermuda; the Bahamas Princess (formerly the King's Inn) and the Xanadu Princess Tower (formerly the International) in Freeport; the Acapulco Princess and the Pierre Marques in Mexico; and the Francis Drake in San Francisco. The American millionaire recluse Howard Hughes acquired

7830-519: Was invented in 1991 by Wayne Thomas at The Welding Institute (TWI, UK) and found high-quality applications all over the world. All of these four new processes continue to be quite expensive due to the high cost of the necessary equipment, and this has limited their applications. The most common gas welding process is oxyfuel welding, also known as oxyacetylene welding. It is one of the oldest and most versatile welding processes, but in recent years it has become less popular in industrial applications. It

7920-475: Was one of the wealthiest tycoons of his day, with operations spanning 23 countries, Ludwig remained completely obscure due to his reclusive lifestyle. He "avoided the press like the plague", keeping a low profile throughout his business career. He only gave one interview during his lifetime, which he granted to Dero A. Saunders of Fortune Magazine in 1957. Ludwig was #1 on the Forbes 400 in 1982. Daniel Keith Ludwig

8010-457: Was the description of a stable arc discharge and the indication of its possible use for many applications, one being melting metals. In 1808, Davy, who was unaware of Petrov's work, rediscovered the continuous electric arc. In 1881–82 inventors Nikolai Benardos (Russian) and Stanisław Olszewski (Polish) created the first electric arc welding method known as carbon arc welding using carbon electrodes. The advances in arc welding continued with

8100-524: Was used in the construction of the Iron pillar of Delhi , erected in Delhi , India about 310 AD and weighing 5.4  metric tons . The Middle Ages brought advances in forge welding , in which blacksmiths pounded heated metal repeatedly until bonding occurred. In 1540, Vannoccio Biringuccio published De la pirotechnia , which includes descriptions of the forging operation. Renaissance craftsmen were skilled in

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