AN IMPROVED FERRITE-BAINITE HIGH STRENGTH LOW ALLOY STEEL COMPOSITION AND AN IMPROVED PROCESS FOR PRODUCING THE SAME

摘要

The present invention relates to an improved ferrite-bainite high strength low alloy steel composition comprising (by weight %) C: 0.18- 0.22; Si: 0.25-0.30; S: 0.035 max; P: 0.025 max; Mn: 0.99-1.10; Ni: 0.30-0.35; Cr: 0.45-0.50; Cu: 0.45-0.50; Al: 0.075 max; Nb: 0.050-0.055; V: 0.040-0.045; and N: 0.0100-0.0125. The invention also relates to a process for producing an improved ferrite-bainite high strength low alloy steel composition. The process steps comprises soaking plurality of metal plates, rolling the plates at predetermined rolling temperature, cutting predetermined size of strips from the rolled plates, making an appropriate length and diameter of hole in the strip, embedding a stainless steel sheathed thermocouple into the hole, soaking the strips in a furnace at an appropriate austenitisation temperature for predetermined period, removing the material from furnace after soaking and cooling the strips in air.