Low alloy steel composition

(1) Low carbon: Due to high requirements for toughness, weldability, and cold formability, its carbon content does not exceed 0.20%;
(2) Adding alloy elements mainly composed of manganese;
(3) Adding auxiliary elements such as niobium, titanium, or vanadium: A small amount of niobium, titanium, or vanadium forms fine carbides or carbonitrides in the steel, which is beneficial for obtaining fine ferrite grains and improving the strength and toughness of the steel;
In addition, adding a small amount of copper (≤ 0.4%) and phosphorus (about 0.1%) can improve corrosion resistance. Adding a small amount of rare earth elements can remove sulfur and gas, purify steel, improve toughness and process performance.