摘要
本文设计了由淬火、深冷步骤、回火步骤等不同组合的多种处理方式,着重考察深冷步骤的顺序对EM35合金组织与性能的影响。采用场发射扫描电镜、X射线衍射、洛氏硬度、干式摩擦等表征合金的组织结构与力学性能。研究结果发现3次550℃ ×1 h回火之后进行−180℃ ×6 h深冷的复合处理可使EM35合金具有最佳的硬度及耐磨性能。深冷步骤放置在回火之后(后置深冷)的处理方式有利于保持重元素的固溶强化效应和超细弥散强化效应;而深冷步骤放在回火之前的方式则促进重元素以MC碳化物相析出。深冷后实施的较高温度回火导致碳化物长大粗化、并降低合金的耐磨性能。
Different treatments including tempering and deep-cryogenically treating (DCT) were designed for the quenched EM35 alloy, focusing on investigating the effect of the sequence of tempering step and DCT step on the microstructure and performance. Scanning electronic microscopy, X-ray diffraction, HRC indentation, and dry sliding of the pin-on disk were used to characterize the microstructure, hardness, friction coefficient, and wear resistance. It is found that the complex treatment A2 of 550˚C ×1 h tempering for three times followed by DCT of −180˚C ×6 h can lead to a good performance combination of hardness and wear resistance. After tempering, DCT is beneficial to maintain the solid-solution strengthening of heavy elements of the matrix and to enhance the dispersion strengthening of carbide refinement. The treatment with tempering after DCT promotes the formation of heavy-element-rich MC carbide. After A2 treatment, over-tempering at elevated temperature induces overaging and degrades the wear resistance of EM35 alloy.
出处
《材料科学》
CAS
2021年第10期1098-1105,共8页
Material Sciences
