Cr13不锈钢CMT堆焊金属表面高压滚压层结构与性能研究

发布时间：2018-05-22 19:47

本文选题：CMT + 表面高压滚压　；参考：《机械工程学报》2017年08期

【摘要】：采用冷金属过渡(Cold metal transfer,CMT)(ER309L氩弧焊丝φ2.5 mm)焊接方法对Cr13不锈钢进行堆焊,为改善补焊工艺中堆焊金属的组织以及性能的不均匀性,对堆焊金属进行表面高压滚压塑性变形处理。滚压压力为12 k N,滚压时间为15 min,6个滚针(GCr15,φ8 mm×10 mm)等角分布,滚针旋转速率为2 r/min。之后借助光学显微镜(Optical microscope,OM)、扫描电子显微镜(Scanning electron microscopy,SEM)、显微硬度仪、摩擦磨损试验仪、电化学工作站对其显微组织、硬度、耐磨性和耐蚀性进行评价。结果表明,堆焊金属经表面滚压后,晶粒均明显细化且存在一定厚度的高压滚压层和过渡层。高压滚压层的平均显微硬度为403.62 HV,原始堆焊金属的平均显微硬度为287.83 HV。高压滚压层的摩擦特性更为稳定且磨损量更小,但耐蚀性变差。高压滚压后组织和性能的不均匀性得到改善。
[Abstract]:Cold metal transfer er 309L argon arc welding wire 蠁 2.5mm was used for surfacing welding of Cr13 stainless steel. In order to improve the non-uniformity of microstructure and properties of surfacing metal in the repair welding process, the surface of surfacing metal was treated with high pressure rolling plastic deformation. The rolling pressure is 12 KN, the rolling time is 15 min, the distribution of six needle GCr15, 蠁 8 mm 脳 10 mm) isobarameters, and the rotating rate of the needle is 2 r / min. The microstructure, hardness, wear resistance and corrosion resistance were evaluated by means of optical microscope, scanning electron microscope (SEM), microhardness tester, friction and wear tester and electrochemical workstation. The results show that after the surfacing metal is rolled on the surface, the grain size is obviously refined and there is a certain thickness of high pressure rolling layer and transition layer. The average microhardness of the high pressure rolling layer is 403.62 HVV and the average microhardness of the original surfacing metal is 287.83 HV. The friction characteristics of the high pressure rolling layer are more stable and the wear amount is smaller, but the corrosion resistance becomes worse. The nonuniformity of microstructure and properties was improved after high pressure rolling.
【作者单位】：武汉大学水力机械过渡过程教育部重点实验室;
【基金】：国家自然科学基金(51371128) 湖北省自然科学基金(2014CFB707)资助项目
【分类号】：TG455

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