近年来,随着飞机和导弹工程的发展,在冶金和热处理方面的要求越来越高。在提高抗拉强度的同时,要求有延展性,并消除裂纹、变形和内应力。为了发挥钢的最高强度和最好的性能,钢必须经过热处理。钢件在 In recent years, with the development of aircraft and missile engineering, the requirements for metallurgy and heat treatment have become higher and higher. In improving the tensile strength at the same time, require ductility and eliminate cracks, deformation and internal stress. In order to exert the highest strength and the best properties of steel, the steel must be heat treated. Steel in