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用25Cr2Ni4WA钢试样,经奥氏体化后用食盐水、油、空气冷却并低温回火,然后进行拉伸试验与冲击试验,并用光学金相、扫描断口、断口镀镍金相、断口-金相双面扫描以及X—射线衍射等分析方法,研究了力学性能的变化规律及其微观机理。结果发现,马氏体束的尺寸随着冷却速度的增大而减小,从而提高了强度及韧性;马氏体束是这种钢的抵抗变形和断裂的基本组织单元;自回火不能消除淬火应力,细化马氏体束的效果必须在充分消除淬火应力后才能显示出来。对于重要零件,条状马氏体钢要在淬火并低温回火后使用。
With 25Cr2Ni4WA steel samples, the austenitized salt water, oil, air cooling and tempering at low temperature, and then tensile test and impact test, and the optical metallography, scanning fracture, fracture nickel plating metallography, fracture - Metallographic double-sided scanning and X-ray diffraction analysis of the mechanical properties of the law of variation and its micro-mechanism. The results show that the size of the martensite beam decreases with the increase of the cooling rate so as to improve the strength and toughness; the martensite beam is the basic unit of the steel that resists the deformation and fracture; and the self-tempering can not be eliminated Quenching stress, the effect of refining the martensite beam must be fully eliminated after the quenching stress can be displayed. For important parts, strip martensitic steel should be used after quenching and tempering at low temperature.