表面纳米化AISI H13钢的渗铬处理及其耐磨性

对表面纳米化（SNC）处理后的热作模具钢AISI H13钢进行渗铬处理,用扫描电子显微镜、透射电子显微镜、纳米压痕仪和摩擦磨损试验机研究了渗铬层成分、微观结构、硬度和耐磨性。结果表明,经600及1 050℃的复合渗铬处理后,SNC样品表面形成了厚约30μm的连续渗层,是经相同复合渗铬处理的粗晶样品上渗层厚度的3倍。受益于渗铬层中较小的晶粒尺寸和较高的硬度,加之其成分、结构和力学性能在较大深度范围内较为平缓的梯度变化,SNC H13钢经渗铬处理后耐磨性得到显著提高。

Chromizing treatment of the surface nano-crystallized AISI H13 steel and its wear resistance

A hot-working AISI H13 tool steel was subjected to a combined process consisting of surface nano-crystallization(SNC) and chromizing treatment successively.The composition,microstructure,hardness and wear resistance of the chromized surface layer were characterized by using scanning and transmission electron microscopes,a nano-indenter and a tribometer.It was shown that a continuous chromized layer of approximately 30 μm in thickness was formed on the SNC sample after a dual chromizing treatment at both 600℃ and 1 050℃ consecutively,as thick as about 3 times of that on the coarse-grained sample after the same chromizing treatment.In addition,the wear resistance of the SNC-chromized sample was enhanced significantly,due to smaller grain size and a higher hardness,as well as smoother gradient variations of microstructure,composition and hardness across a greater depth in the formed chromized surface layer.