【摘要】 低成本、高性能耐磨钢的需求增长及其开发都在进行中.本研究根据对耐磨钢性能的要求,试制了三种不同合金化方式的低合金耐磨钢,利用金相显微镜、透射电子显微镜、洛氏硬度计、万能材料试验机、夏氏冲击试验机和磨粒磨损实验机研究了其组织和性能,讨论了它们间的关系.结果表明: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45 HRC,屈服强度大于1 000 MPa,抗拉强度大于1 500 MPa,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50 HRC,屈服强度大于900 MPa,抗拉强度大于1 500 MPa,有一定的塑性和韧性,耐磨性良好,与商用淬火-回火耐磨钢类似;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.更多还原

【Abstract】 Increase of demand and development of abrasion resistant steel with low-cost and high performance are in progress. In the present study,three types of lowalloy abrasion resistant steels alloyed according to the 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. 25 C type steel subjected to different heat treatments are obtained martensitic microstructure in which self-tempering happened,and have hardness larger than 45HR C,proof strength higher than 1000 MPa,tensile strength larger than 1 500 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. 25 C type steel subjected to tempering at 250 ℃ after water-quenched from 860 ℃ or 920 ℃. Microalloying of V has no evident effect on microstructure and properties of the steel. 0. 33 C type steel subjected to continuous cooling at cooling rate higher than 2 ℃ / s or blow-cooling to room temperature after austenized at 860 ℃ or 920 ℃ can obtain a mixed microstructure consisting of bainite and martensite,has a hardness higher than 50HR C,proof strength larger than 900 MPa,tensile strength larger than 1500 MPa and a certain of plasticity as well as toughness,and an excellent abrasion resistance similar to that of commercial abrasion resistant steel which must be tempered after austenized. However,abrasion resistance of the steel under impact condition will be better than that of the commercial steel because it has higher work-hardening ability and excellent impact toughness. The wear rate of the tested steels subjected to different heat treatment increases with the grain size of abrasive paper and the load. The effect of load is larger,while effect of grain size of abrasive paper is smaller.更多还原