Effect of Alloying Elements on Mechanical Properties of High P Low Alloy Steels

Four numbers of laboratory heats containing 0.19 % P, 23–60 ppm B and varying amounts of other elements, viz. Cr, Cu, Ni, B and Nb were made through ingot casting route. Effects of these elements on mechanical properties were studied after hot rolling the ingots in an experimental rolling mill. Nb increased yield strength and ultimate tensile strength considerably though its beneficial effect on toughness was not realized in the presence of boron. While the beneficial effect of B in the range of 23–60 ppm was not realized, the steel without B exhibited highest toughness value. In this particular steel, the volume fraction of {100}〈001〉 texture component was lowest and percentage of HAGBs was highest, both of which contributed to the increase in toughness value. Further, this steel also exhibited the distribution of highest numbers of fine grains suitable for structural applications.