FATIGUE BEHAVIOUR OF M/B DUPLEX STRUCTURE IN A HIGH CARBON Cr-Mo-W STEEL

Determination was carried out of fatigue crack propagation rate of steel 65Cr5Mo3W2VSiTi (LM2)with various bainite contents and M/B duplex structure tempered at various tempera- tures.The threshold value of fatigue for each processing was estimated by experimental data. The mechanism for fatigue crack propagation of M/B duplex structure in steel LM2 seems to be non-continuous.The calculated fatigue crack micro-propagation rates are found to agree with the experimental data.

高碳Cr—Mo—W钢M/B复相组织疲劳行为研究

用紧凑拉伸试样测定了65Cr5Mo3W2VSiTi(LM2)钢不同贝氏体量和不同回火温度的M/B复相组织的疲劳裂纹扩展速率,根据试验数据估算了各工艺的疲劳门槛值。结果表明,LM2钢M/B复相组织的疲劳裂纹扩展属非连续扩展机制。

韧性相数量对高碳Cr－Mo－W－V钢多相混合组织综合力学性能的影响

研究了不同热处理状态下６５Ｃｒ５Ｍｏ３Ｗ２ＶＳｉＴｉ钢中韧性相下贝氏体和残留奥氏体数量对钢综合力学性能的影响。结果表明：适量形态分布良好的韧性相可以改善高碳高合金钢的强韧性配合，提高其疲劳抗力。

热处理工艺对LM2钢超塑性的影响

本文研究了热处理工艺对LM2钢(65Cr5Mo3W2VSiTi钢)超塑性的影响。在1030℃下两次循环淬火是实现LM2钢超塑性的最佳热处理工艺;按此工艺进行预处理后,在830℃、初始应变速率7.8×10^(-4)s^(-1)的条件下,该钢的超塑延伸率可达247%。