激光直接沉积成形15Cr21Ni7-xMo不锈钢显微组织及性能研究

发布时间：2018-06-29 15:27

本文选题：激光直接沉积成形 + CrNi-xMo不锈钢　；参考：《应用激光》2017年01期

【摘要】：通过激光直接沉积成形技术制备不同Mo元素含量的Cr-Ni不锈钢,对工艺参数进行优化,并对Cr-Ni不锈钢合金进行成分设计与组织性能评价。采用半导体激光器直接沉积成形15Cr21Ni7双相不锈钢合金粉添加xMo(x=0%、1%、2%、3%、4%),在激光功率1 800 W,激光扫描速度5mm/s,搭接率30%,送粉率8.9g/min的优化工艺参数下获得了长宽高分别为10mm×10mm×4mm的不锈钢块体样品。利用光学显微镜、电子探针、X射线衍射仪、显微硬度计及电化学测试系统进行了沉积层的显微组织、成分、物相及显微硬度、耐蚀性分析。实验结果表明,沉积层无气孔和裂纹等缺陷,成形性良好;沉积层的中部稳定,显微组织主要由岛状枝晶、奥氏体枝晶和枝晶间区域为铁素体、奥氏体、合金碳化物的混合组织组成;随Mo含量的增加,沉积层的耐蚀性随Mo含量的增加先升高后降低,当Mo含量达到3%时,耐蚀性获得最高值:自腐蚀电流密度为167.21nA/cm~2,自腐蚀电位为-142.26 mV。沉积层的显微硬度随Mo含量的增加变化不大,其平均显微硬度在340~390HV。
[Abstract]:Cr-Ni stainless steel with different Mo content was prepared by laser direct deposition. The process parameters were optimized and the composition design and microstructure and properties of Cr-Ni stainless steel alloy were evaluated. In this paper, 15Cr21Ni7 duplex stainless steel alloy powder formed by direct deposition of semiconductor laser is used to add XMo (XMo). The stainless steel bulk samples with length and width of 10mm 脳 10mm 脳 4mm are obtained under the optimized technological parameters of laser power 1 800 W, laser scanning speed 5 mm / s, lap ratio 30 mm, powder feeding rate 8.9g/min. The microstructure, composition, phase, microhardness and corrosion resistance of the deposited layer were analyzed by means of optical microscope, electron probe X-ray diffractometer, microhardness tester and electrochemical measurement system. The results show that there are no defects such as porosity and crack in the deposited layer and the formability is good, the middle part of the deposit is stable, the microstructure is mainly island dendrite, the zone between austenitic dendrite and dendrite is ferrite, austenite, and austenite. With the increase of Mo content, the corrosion resistance of the deposit increases first and then decreases with the increase of Mo content. When Mo content reaches 3, the corrosion resistance reaches the highest value: the self-corrosion current density is 167.21nA / cm ~ (-2), the self-corrosion potential is -142.26 MV. The microhardness of the deposited layer changed little with the increase of Mo content, and the average microhardness was 340 ~ 390HV.
【作者单位】：东北大学材料科学与工程学院材料各向异性与织构教育部重点实验室;
【基金】：国家重点研发计划资助项目(项目编号:2016YFB11002003) 教育部基本科研业务费重大创新资助项目(项目编号:N130810002)
【分类号】：TG142.71

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