摘要
本文研究了不同热处理规程对5CrMnMo钢的强度、塑性、冲击韧性等指标的影响。结果表明:随淬火温度升高,强度、塑性变化不大,冲击韧性下降,断裂韧性略有提高;随回火温度升高,强度下降,塑性和冲击韧性提高,断裂韧性在550℃回火时出现峰值;因此采用880℃加热淬火,550℃回火工艺可使钢获得较高的强韧性。
The effect of the differenf heat treatment rules on the indexes of the strength, the plasticity, the impact toughness and the fracture toughness was discussed. when the quenching temperaturs is raised, the strength and the pla- sticity arc not changed appreciably, but the impact toughness is decreased and the fracture toughness inereased a bit. when the tempering temperature is raised, the strength is decreased, the plasticity and the impact toughness arc increased and the fracture toughness gets the crest value at 550℃. The specimens after isothermal treatment at 249℃ for 3 hours and tempering at 480℃ were compared with those after 6 hour isothermal treatment at 450℃, and it was found that the strength and fracture toughness of the former are increased a bit, but the fracture toughness and impact toughness are lower than that of the commonly quenche and tempered specimens of the equal hardness. The results show that 5CrMnMo steel will obtain higher strength ant toughness when the technology of quenching at 880℃ and tempering at 550℃ is employed.
