热处理工艺对高C-Cr高强耐磨钢组织和性能的影响

设计了一种高C-Cr高强耐磨钢,测试了末端淬透性,研究了不同热处理工艺对微观组织演变和性能的影响,测试了力学性能和耐磨损性能,利用SEM和TEM表征了微观组织。试验结果表明,随距离淬火端距离的增大,试验钢的硬度呈现单调递减的趋势,0~2.5 cm为硬度平缓降低阶段,布氏硬度在63~65HRC的区间。马氏体淬火+回火处理后,试验钢基体组织主要为马氏体板条,板条尺寸大小不一。经贝氏体等温淬火处理后,贝氏体板条相互平行,板条尺寸平均。贝氏体板条间存在薄膜状的残留奥氏体,贝氏体板条内部存在长度为100~150 nm的碳化物析出相,析出相与贝氏体板条呈60°取向排列。磨损过程中,达到800转时,马氏体基体试验钢失重168 mg,贝氏体基体失重192 mg,增加了14.28%,马氏体基体的耐磨损性能更高。而贝氏体基体的力学性能却明显高于马氏体基体,屈服强度达到1 955 MPa,抗拉强度达到了2 485 MPa,伸长率仍然达到了7%。

Influence of heat treatment on microstructure and properties of high C-Cr high strength wear-resistant steel

A high C-Cr high strength wear-resistant steel was designed. The end hardenability was tested. The influence of heat treatment on microstructure and properties was studied. The mechanical property and wear behavior was tested. The microstructure was characterized using SEM and TEM. The results indicated that the hardness was decreased with the increase of distance from the quench place, and it had a gently decrease trend at a distance of 0-2.5 cm, where the Brinell hardness was 63-65HRC. The microstructure of the experimental steel was almost martensite after quench and temper treatment, and the size of the martensite plate was different. After bainite isothermal quenching treatment, the bainite plates were parallel to each other, and the size of the bainite plate was uniform. There were thin films of retained austenite between bainite laths, and carbide precipitates with the length of 100-150 nm in the bainite plate. The precipitates and bainite laths were arranged in a 60° orientation. During the wear process, at 800 r/min, the weight loss of martensite was 168 mg, while 192 mg of bainite increased by 14.28%. The wear resistance of the martensite matrix was higher, while the mechanical properties of the bainite matrix were obviously higher than that of the martensite matrix. The yield strength was 1 955 MPa, tension strength was 2 485 MPa and the elongation was still 7%.