5.6 Alloying Elements in Steels
As mentioned before, the steels that you may be asked to
weld at different times are likely to belong to different
specifications, or even to the same specification, and will have
different compositions depending on the steel mill supplying
the steel. Alloy atoms are of a different size than the iron
atoms. Some are smaller, some are larger. In either case
their intended effect is to cause small distortions in the cubic
structure of the steel, as shown in Figure 5.17.