P550不锈钢表面激光熔覆Ni-Cr-Mo合金涂层的实验研究  

Experimental study on laser cladding of Ni-Cr-Mo alloy coating on surface of P550 stainless steel

作　　者：毛洁 刘宗德[1] 路鑫杰 潘朝阳 申越 MAO Jie;LIU Zongde;LU Xinjie;PAN Chaoyang;SHEN Yue(School of Energy Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《兵器材料科学与工程》2024年第5期84-92,共9页Ordnance Material Science and Engineering

基　　金：装备预研领域基金项目(61409220202)。

摘　　要：采用激光熔覆技术在P550无磁不锈钢表面制备了Ni-Cr-Mo耐蚀合金熔覆层,研究了激光扫描速率对磁性能与耐蚀性的影响。结果表明:激光扫描速率为1 cm/s时,熔覆后样品的磁性显著增加,相对磁导率由1.005增至1.012,矫顽力由28.075 Oe增至163.197 Oe,剩磁由0.125 Gs增至1.627 Gs;当扫描速率大于5 cm/s时,熔覆后的样品无磁性能良好。激光扫描速率较低时,热影响区内发生多晶转变,生成高温铁素体,高温铁素体具有铁磁性,从而使样品磁性显著增加。P550无磁不锈钢钝化区窄,点蚀电位为0.146 VSCE,动电位极化后样品表面出现大量点蚀坑。而Ni-Cr-Mo合金熔覆层的钝化区较宽且稳定,点蚀电位高达0.866 VSCE,熔覆层耐点蚀能力显著优于P550无磁不锈钢;随扫描速率的提高,熔覆层的钝化电流密度下降,阻抗模值增大。这是因为随扫描速率的提高,熔覆层晶粒尺寸细化、元素偏析减弱,有利于生成均匀、稳定、致密的钝化膜。Ni-Cr-Mo corrosion resistant alloy cladding layer was prepared on P550 non-magnetic stainless steel surface by laser cladding technology.The influence of laser scanning rate on magnetic properties and corrosion resistance was studied.The results show that when the laser scanning rate is 1 cm/s,the magnetic properties of the samples after coating increase significantly,the relative permeability increases from 1.005 to 1.012,the coercivity increases from 28.075 Oe to 163.197 Oe,and the remanence increases from 0.125 Gs to 1.627 Gs.When the scanning rate is greater than 5 cm/s,the non-magnetic properties of the coated sample are good.When the laser scanning rate is low,polycrystalline transformation occurs in the heat affected zone and high temperature ferrite is formed.The high temperature ferrite is ferromagnetic,which significantly increases the magnetic properties of the sample.The passivation zone of P550 non-magnetic stainless steel is narrow,the pitting potential is 0.146 VSCE,and a large number of pitting pits appear on the sample surface after potentiodynamic polarization.The passivation zone of Ni-Cr-Mo alloy cladding layer is wide and stable,the pitting potential is as high as 0.866 VSCE,and the pitting resistance of Ni-Cr-Mo alloy cladding layer is significantly better than that of P550 non-magnetic stainless steel.With the increase of scanning rate,the passivation current density of cladding layer decreases and the impedance mode value increases.This is because with the increase of the scanning rate,the grain size of the cladding layer is refined and the element segregation is weakened,which is conducive to the formation of uniform,stable and dense passivation film.

关 键 词：激光熔覆 扫描速率 NI-CR-MO P550无磁不锈钢 磁性能 耐腐蚀性能 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG178