莱钢科技—低合金耐磨钢的组织性能介绍.doc

低合金耐磨钢的组织与性能 刘春明王立军 (东北大学 材料与冶金学院, 辽宁 沈阳 110) 摘要：0.25C钢经不同工艺热处理后均获得了马氏体组织，并发生不同程度的自回火现象，硬度均大于45HRC，屈服强度大于1000MPa，抗拉强度大于1500MPa，并具有一定的塑性和韧性；在860℃淬火或920℃淬火并250℃回火后，实验钢的硬度、强度、塑性和韧性有最佳的配合，耐磨性最佳；V微合金化对钢的组织和性能没有明显影响。0.33C钢860℃或920℃奥氏体化后以等于或大于2.0℃/s的冷速连续冷却或风冷至室温，回火或不回火即可得到由贝氏体与马氏体组成的混合组织，硬度超过50HRC，屈服强度大于900MPa，抗拉强度大于1500MPa，有一定的塑性和韧性，耐磨性良好，与商用淬火-回火耐磨钢钢类似；但由于具有高的加工硬化能力和良好的冲击韧性，在冲击条件下的耐磨性会优于商用钢。不同工艺热处理后的试验钢的磨损率随砂纸粒度和载荷增大而增大，载荷的影响较大，而磨粒的影响较小。 关键词：耐磨钢；马氏体；磨损率中图分类号： 文献标识码：Ademand and development of abrasion resistant steel with high performance are in progress. In the present study, three types of low alloy abrasion resistant steels alloyed different considerations were trial-produced according demand on properties of abrasion resistant steel. And their microstructures and properties were investigated by optical microscopy, transmission electron microscopy, Rockwell hardness tester, universal testing machine, Charpy impact testing machine and grain abrasion tester and the relationship between microstructure and properties discussed. The experimental results showed that all of 0.25C type steel subjected to different heat treatments are obtained martensitic microstructure in which self-tempering happened, and have hardness larger than 45HRC, proof strength higher than 1000 MPa, tensile strength larger than 1500 MPa and a certain of plasticity as well as toughness. Optimal combination of hardness, strength, plasticity and toughness, and optimal abrasion resistance can be obtained for 0.25C type steel subjected to tempering at 250 oC after water-quenched from 860 oC or 920 oC. Microalloying of V has no evident effect on microstructure and properties of the steel. 0.33C type steel subjected to continuous cooling at cooling rate higher than 2 oC/s or blow-cooling to room temperature after austenized at 860 oC or 920 oC can obtain a mixed microstructure consisting of bainite and martensite, has a hardness higher than 50HRC, proof strength larger than 900 MPa, tensile strength larger