Abstract: The content of carbon and alloying elements, surface residual stress in the microstructure of 40Cr steel after quenching on various time held at temperature is studied by means of electron probe and X-ray diffraction techque, The tensile, once and repeated impact, residual stress, scope impact, wear etc are tested after tempering. The influence of shortening the heat of the quenching held at temperature on microstructure and properties is studied in this paper. Hence the austenitic nonuiformity quenching is adoptable from the point of view of strength materials.

Key words: 淬火保温时间, 中碳结构钢