低成本热轧700MPa级载重汽车车厢板的耐磨性能

摘要

通过常温摩擦磨损试验对低成本热轧700 MPa级载重汽车车厢板耐磨性能进行了研究,并探讨了显微组织、纳米析出物对其耐磨性能的影响规律.结果表明:当磨损时间为40 min时,700 MPa级车厢板的质量损失为40.7 mg,表面塑性变形层厚度为37μm;微裂纹易在铁素体与珠光体或贝氏体相界面形核并扩展；当碳化物呈条状或颗粒状时,变形过程中不易发生应力集中,碳化物与基体界面之间无明显的微裂纹形成；700MPa级车厢板中的纳米析出物(Nb,Ti)C可有效地提高其耐磨性,其磨损机理以磨粒磨损为主.%The wear resistance of low-cost hot-rolled 700 MPa grade plate for heavy duty truck carriage was studied by room temperature friction and wear test,and effects of microstructure,nano-scale precipitation on wear resistance were investigated.The results indicate that when the wear time was 40 rnin,the weight loss of the plate was 40.7 mg,and the thickness of surface plastic deformation layer was 37μu Microcracks nucleated easily and propagated on phase interface between ferrite and pearlite or bainite.When the carbides were stripe or granular in shape,stress concentration appeared difficultly,and there were no microcracks forming on phase interface between carbides and matrix The nano-scale precipitation (Nb,Ti)C in the plate could effectively improve its wear resistance,and the wear mechanism of the plate was mainly abrasive wear.