Ti掺杂对Cr-Fe合金粉激光熔覆层组织与性能的影响

Influence of Ti-doping on microstructure and properties of Cr-Fe alloy powder laser cladding

采用CO2激光加工机,在Q235钢基体表面预涂覆加入不同Ti含量(1%~4%)的高碳Cr-Fe合金粉,制备熔覆涂层。采用OM、XRD及硬度测试、耐磨测试、腐蚀性能测试等手段,研究了Ti掺杂对涂层组织性能的影响。结果表明,加入Ti减小了熔覆涂层初生碳化物尺寸,使组织均匀细化,物相为α-Fe、CrFe、(Cr,Fe)7C3、Cr7C3、TiC和Cr23C6。当加入Ti量为2%时,涂层表面平均硬度达到最高917.8 HV0.2,磨损率为0.491 mg·mm-2,自腐蚀电流密度最小,为517.6μA·cm-2。

Q235 steel substrate surface was pre-coated with high-carbon Cr-Fe alloy powder with different contents ( 1%-4%) Ti doping, and laser cladding was prepared by using CO2 laser. Influence of Ti doping on microstructure and properties of the cladding was investigated by using OM, XRD, hardness, abrasion and corrosion test. The results show that Ti doping decreases the size of the primary carbide of the cladding, makes the microstructure homogeneous and precise. The phases of the cladding include α-Fe, CrFe, (Cr,Fe)7C3, Cr7C3, TiC and Cr23 C6 . When mass fraction of Ti is 2%, the average hardness reaches maximum value of 917. 8 HV0. 2, the wear rate of the coating surface is 0. 491 mg·mm-2 , and the corrosion current density reaches the minimum value of 517. 6 μA·cm-2 .