送粉速率对激光熔覆内壁FeCoNiCrMo0.2涂层组织及性能的影响  

Effect of Powder Feeding Rate on Microstructure and Properties of Internal FeCoNiCrMo0.2 Coating by Laser Cladding

作　　者：任向宇 孙文磊[1] 田爽 王秋雨 REN Xiangyu;SUN Wenlei;TIAN Shuang;WANG Qiuyu(College of Mechanical Engineering,Xinjiang University,Urumqi 830017,China;Chongqing Pengshui Minzu Secondary School,Chongqing 409600,China)

机构地区：[1]新疆大学机械工程学院,乌鲁木齐830017 [2]重庆市彭水民族中学,重庆409600

出　　处：《表面技术》2025年第5期188-202,共15页Surface Technology

基　　金：新疆维吾尔自治区重点研究项目(2022B01036);新疆维吾尔自治区科研创新项目(XJ2022G011)。

摘　　要：目的改善石化领域管状内壁零件的抗磨损、抗腐蚀性能,延长零件的使用寿命。方法使用激光熔覆技术在316L钢管内壁制备5种不同送粉速率下的FeCoNiCrMo0.2高熵合金(HEA)涂层。通过物相组成、晶粒结构、硬度测试、磨损试验,分别评价5种HEA涂层中固溶体的分布情况、微观组织细密程度,以及硬度和抗磨损抗犁切性能,并对磨损机制进行分析。最后利用动电位极化曲线表征HEA涂层的抗腐蚀性能。结果HEA涂层由单相FCC构成,且其微观组织主要由柱状晶、胞状晶组成。涂层的磨损机制均包括黏着磨损和磨粒磨损。在送粉速率为15 g/min时,涂层形成了更多细密的胞状晶粒组织,增加了涂层中硬质相的含量,固溶强化效应较大,涂层的摩擦因数降至0.58,改善了HEA涂层的摩擦学性能。在电化学测试中,送粉速率为15g/min时HEA涂层拥有最低的自腐蚀电流密度(J_(corr)),该涂层表面原位生成的钝化膜中含有更多的抗腐蚀性物质(例如Cr_(2)O_(3)等)。结论送粉速率通过影响内壁HEA涂层的物相组成、组织演变和元素分布,显著提升了涂层的硬度和摩擦学性能。通过优化送粉速率,有助于降低HEA涂层的摩擦因数和磨损,也有助于增强涂层在腐蚀过程中形成钝化膜的密度,增大Cr_(2)O_(3)、MoO_(2)等抗腐蚀性物质的含量。The work aims to improve the wear and corrosion resistance of tubular and inner wall parts(such as oil and gas transmission pipes)in petrochemical and other fields,and then extend the service life of parts.In this paper,high entropy alloy(HEA)coatings of FeCoNiCrMo0.2 were prepared by laser cladding at five different powder feeding rates on the inner surface of the 316L tube.Based on the macroscopic morphology,phase composition,grain structure,element distribution,hardness test,wear test and electrochemical corrosion characterization,the solid solution distribution,microstructure fineness,alloying element distribution,hardness and wear resistance of the five HEA coatings were evaluated,and the wear mechanism was analyzed.Finally,the corrosion resistance of HEA coatings were characterized by potentiodynamic polarization curve.The results showed that the five coatings were all composed of simple FCC phases,and the microstructure was mainly composed of columnar and cellular crystals.The microstructure of HEA coatings with 6 g/min and 18 g/min powder feeding rates were mainly composed of coarse columnar crystals,accompanied by a small amount of fine cellular crystals.The HEA coating at 6 g/min had the greatest dilution of 52% and had the greatest thermal impact on the substrate.Moreover,the HEA coating prepared at the powder feeding rate of 18 g/min contained obvious unmelted particles,and the forming quality was poor.The curves of coefficient of friction(COF)for 6,9,12,15,18 g/min were approximately stabilized at about 0.68,0.65,0.61,0.58,and 0.63,respectively.The powder feeding rate of 15 g/min had a greater solid solution strengthening effect on the coating,and the solid solution was uniformly distributed.And the solidification of the coating at this time formed more fine cellular crystals,which reduced the elemental segregation during the solidification process and increased the hard phase content in the coating.In addition,the rate decreased the COF of the coating to 0.58,and its wear volume loss was 2.456 mg,wh

关 键 词：激光熔覆 高熵合金 微观组织 显微硬度 磨损行为 电化学腐蚀 

分 类 号：TG174.4[金属学及工艺—金属表面处理]