亚临界热处理Cr13Mn3MoV2高铬铸铁的硬化行为和耐磨性

Hardening Behavior and Abrasion Resistance of the Cr13Mn3MoV2 High Chromium Cast Iron Subjected to Sub-critical Treatment

研究了Cr13Mn3MoV2高铬铸铁在亚临界处理时的硬化行为和耐磨性。研究表明,通过亚临界热处理可以使含有大量残留奥氏体的高铬铸铁产生二次硬化,从而提高高铬铸铁的硬度和耐磨性。利用合金热力学理论计算了奥氏体中碳的活度,固溶于奥氏体中的Mo和V会降低奥氏体中C的活度,对C在亚临界热处理过程中扩散的阻碍作用,所以与没有添加Mo和V的高铬铸铁比较,添加Mo和V的高铬铸铁二次硬化峰的出现需要更长的保温时间。添加Mo和V的高铬铸铁在亚临界热处理时除了二次碳化物(Fe,Cr)23C6的析出外,还有Mo2C和VCr2C2碳化物析出,有效地提高了合金抗磨料磨损能力。

The hardening behavior and abrasion resistance of high chromium cast iron （HCCI） containing molybdenum and vanadium subjected to sub-critical treatment were studied. Investigation indicates that alloys with higher retained austenite content have obvious secondary hardening effect in sub-critical treating process. Hardness and abrasion resistance are improved due to austenite transforming into martensite and secondary carbide precipitation during sub-critical treatment. The activity of carbon in austenite is calculated by alloy thermodynamic theory. Molybdenum and vanadium soliddissolved in austenite can depress the activity of carbon, which has a inhibitive effect of the precipitation of secondary carbide during sub-critical treating process. Therefore, the secondary hardening peak occurs at longer holding time compared with that of the alloys without molybdenum and vanadium. During sub-critical treatment, the high chromium cast iron containing molybdenum and vanadium precipitates secondary carbides of Mo2C and VCr2 C2 besides （Fe, Cr）23 C6, which improves the abrasion resistance effectively.