论文部分内容阅读
本文研究了不同热处理工艺对5CrNiMo 钢的组织与性能的影响。结果表明,当淬火温度高于900℃时,其马氏体形态是以板条状为主;当回火温度高于450℃时,随着淬火温度的提高,钢的断裂韧性有明显的提高,其室温、高温冲击韧性略有下降。锻模在950～1000℃加热淬火,再高于450℃回火,比传统的热处理后有更好的强韧性。试验结果还表明,此钢臭氏体化后在230℃、280℃等温淬火后获得下贝氏体组织;回火下贝氏体比上贝氏体有较高的断裂韧性、冲击韧性和强度,在230℃等温淬火再500℃经回火后,它的强韧性还优于回火马氏体组织。因此,5CrNiMo 钢热锻模应获得回火板条状马氏体、回火下贝氏体或二者的复合组织为宜。
In this paper, the effects of different heat treatment processes on the microstructure and properties of 5CrNiMo steel were studied. The results show that when the quenching temperature is higher than 900 ℃, the martensite morphology is dominated by lath. When the tempering temperature is higher than 450 ℃, the fracture toughness of steel increases obviously with the increase of quenching temperature , Its room temperature, high temperature impact toughness decreased slightly. Forging die at 950 ~ 1000 ℃ quenching, and then higher than 450 ℃ tempering, heat treatment than the traditional have better toughness. The test results also showed that this steel after the deodorization at 230 ℃, 280 ℃ after isothermal quenching to obtain lower bainite; bainite tempered lower than the upper bainite fracture toughness, impact toughness and strength , After isothermal quenching at 230 ℃ and 500 ℃ after tempering, its toughness is better than the tempered martensite. Therefore, 5CrNiMo steel hot forging dies should be tempered martensite strip, bainitic tempered or both of the composite tissue is appropriate.