![]() Welding technology advanced quickly during the early 20th century as world wars drove the demand for reliable and inexpensive joining methods. Arc welding and oxy-fuel welding were among the first processes to develop late in the century, and electric resistance welding followed soon after. 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. Welding 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. While often an industrial process, welding may be performed in many different environments, including in open air, under water, and in outer space. 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. Welding also requires a form of shield to protect the filler metals or melted metals from being contaminated or oxidized. Pressure may also be used in conjunction with heat or by itself to produce a weld. In addition to melting the base metal, 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, based on weld configuration (butt, full penetration, fillet, etc.), can be stronger than the base material. Welding is distinct from lower temperature techniques such as brazing and soldering, which do not melt the base metal (parent metal). Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. It was voluntary on both sides: the military had the ability to allocate negotiated contracts rather than run a competition and select the lowest priced bidder."Welded" redirects here. One thing about giving contracts to innovative firms and the voluntary nature of it, Bill Knudsen would just call companies up to see whether they could take orders, and then he had the power to clear contracts for those purposes. That was Arthur Herman’s 2013 book talk, “ Freedom’s Forge: How American Business Produced Victory in World War II.” Herman says that Bill Knudsen - who helped create flexible mass manufacturing at Ford - had a few main principles: (1) Give contracts to the most innovative firms, not just defense firms or arsenals (2) Contracts should be voluntary to maximize market incentives and (3) bring in underutilized labor including women, poor Southerners/Appalachians, and African Americans. And that’s why, while the first models of the Lee tank were all riveted, by tanks like the M4 Sherman’s are all welded. Flew it back, showed it to the Army, and said, “There, try and pull it apart if you can.” And so the Army says, “Well, maybe you try welding.” And of course, what they discovered was that the welding not only made it easier and faster to produce the tanks, but it also made them safer because when shells hit riveted armor from the outside, anti-tank shells, those rivets would shake loose and you get flying pieces of metal flying around inside the tank - lethal pieces of metal that we’re killing and injuring the crewmen. So he went out to Detroit, got some guys who he knew understood real industrial welding, and welded together two giant slabs of iron. Rivets are the way to go.” And Knudsen and says, “I don’t believe that.” We use the rivets because the welding is not strong enough. And Bill Knudsen goes to the Army and says why don’t you weld them? And the Army says, “No, it won’t work - the welding. For example, the fact that the Lee tanks that they were making and generating for the British, the M3, was all riveted armor. So they went to work, but in the process - and Bill Knudsen knew this was gonna happen - when you got people who were experts in mass production and who understood how to make changes, modifications, the first things they noticed was that these kinds of tanks had all kinds of design flaws and problems that made them not only hard to produce but that they thought make them not such effective vehicles for war. I don’t know what a tank looks like, but show me one and I’ll tell you whether I can make it or not.” So they fly out to Rock Island Arsenal in Illinois, they put him into a tank one of those old Lee tanks and they drive him around out there with his chief engineer Eddie Hunt and they step out they said, “Yeah, we can make these. One of the first things he does in the process, he makes a call in the summer of 1940 to his pal KT Keller president of Chrysler and says, “KT, can you make tanks?” And KT said, “Well, I don’t know.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |