FOR INTERNAL USE ONLY
Figure 1
1.2
Role of Carbon in Steel
WELDABILITY OF STEELS
When considering a weld, the engineer is concerned with many factors such as design, physical properties, restraint, welding process, fitness-for-purpose etc., which can conveniently be summarized as the base materials “weldability”. Weldability can be defined as “the capacity of a metal to be welded under the fabrication conditions imposed into a specific, suitably designed structure, and to perform satisfactorily in the intended service.” Welding is one of the most important and versatile means of fabrication and joining available to industry. Plain carbon steels, high strength low alloy (HSLA) steels, quench and tempered (Q&T) steels, stainless steels, cast irons, as well as a great many non-ferrous alloys such as aluminium, nickel and copper are welded extensively. Welding is of great economic importance, because it is one of the most important tools available to engineers in his efforts to reduce production, fabrication and maintenance costs. A sound knowledge of what is meant by the word “weld” is essential to an understanding of both welding and weldability. A weld can be defined as a union between pieces of metal at faces rendered plastic or liquid by heat, or pressure, or both, with or without the use of filler metal. Welds in which melting occurs are the most common. The great majority of steels welded today consist of low to medium carbon WELDING AND COATING METALLURGY2
12 October 1999
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