Study on plasma surfacing technology of nickel base alloy for a 20CrNiMo component

某20CrNiMo部件等离子堆焊镍基硬质合金工艺研究 Study on plasma surfacing technology of nickel base alloy for a 20CrNiMo component 陈兴东 CHEN Xingdong 1 2 first-author 郭洋 GUO Yang 1 2 黄岚 HUANG Lan 1 2 黄滔 HUANG Tao 1 2 黄丽 HUANG Li 1 2 王大勇 WANG Dayong 1 2 东方电气集团东方汽轮机有限公司 东方电气集团东方汽轮机有限公司 Dongfang Turbine Co.,Ltd.of Dongfang Electric Corporation Dongfang Turbine Co.,Ltd.of Dongfang Electric Corporation 长寿命高温材料国家重点实验室 长寿命高温材料国家重点实验室 State Key Laboratory of Long-Life High-temperature Materials State Key Laboratory of Long-Life High-temperature Materials 采用等离子粉末喷焊工艺在某20CrNiMo产品上制备Ni基硬质合金层,并进行PT、微观金相、硬度及SEM扫描等分析。结果表明,硬质合金层制备工艺的重复性良好,熔合线平滑、无缺陷。堆焊接头焊层距离熔合线约100μm处有析出相减少带,熔合线处有宽2.5μm的白亮带,熔合线母材侧面存在宽100～200μm的扩散带。扩散带组织为珠光体铁素体及WC的混合组织。通过SEM-EDS分析可知,焊层组织为γ镍固溶体基体及枝晶间碳化物共晶组织。堆焊层硬度检测分布均匀,硬度满足要求,同时焊层具有加工硬化特征。 In this paper,the hardfacing technology of nickel based cemented carbide layer prepared by plasma powder spray welding on a 20CrNiMo product is studied,and the PT,microstructure,hardness and SEM scan are analyzed. The experimental results show that the preparation procedure of cemented carbide layer has good repeatability,smooth bond line and no defects. There is a precipitate reducing band about 100 μm away from the bond line,a 2.5 μm wide white bright band at the bond line, and a about 100～200 μm wide diffusion band at the side of the base metal of the bond line. The microstructure of the diffusion band is a mixture of pearlitic ferrite and WC. Through SEM-EDS analysis,the microstructure of the welding layer is composed of γ-Ni solid solution matrix and interdendritic carbide eutectic structure. The hardness testing of the hardfacing layer is evenly distributed,and the hardness meets the requirements. At the same time,the welding layer has the characteristics of work hardening. 等离子喷焊 WC 镍基硬质合金 金相组织 plasma spray welding WC nickel base cemented carbide microstructure TG455 2022-03-08 6 50