Cr对TiC-VC增强铁基熔覆层耐蚀性及耐磨性的影响

Effect of Cr on corrosion and wear resistances of TiC-VC reinforced ferrite-based laser cladding coatings

通过X射线衍射、扫描电子显微镜、能谱仪、极化曲线和磨粒磨损实验分析,研究了不同Cr加入量对TiC-VC增强铁基激光熔覆层耐蚀性和耐磨性能的影响。结果表明:熔覆层中物相主要为α-Fe,TiC,VC和TiVC2。随着Cr加入量的增加,伴随有残余奥氏体及Cr3C2的出现,且Cr3C2呈长条状部分聚集、部分单独分布。熔覆层的耐蚀性与耐磨性随Cr加入量的增加呈现先增加后降低的趋势。熔覆粉末中加入适量的Cr元素能显著提高熔覆层的硬度与耐蚀性。当添加质量分数为3.0%的Cr时,熔覆层硬度高达1090HV0.2,且相同磨损条件下熔覆层磨损失重仅约为Q235钢的1/26;当添加质量分数为9.0%的Cr时,所得熔覆层的耐蚀性最好,约为不添加Cr时的3.26倍。

The effect of different amounts of Cr in cladding powders on corrosion and wear resistances of cladding layers was investigated by means of X-ray diffractometry(XRD),scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),potentiodynamic polarization and abrasive wear test.The results showed that phases of cladding layers wereα-Fe,TiC, VC and TiVC2.Retained austenite and Cr3C2 would appear with Cr content increasing,and Cr3C2 was long strip and distributed alone or together.The corrosion and wear resistances of cladding layers increased firstly and then decreased with the increasing of Cr addition.Moderate amount of Cr could improve hardness and corrosion resistance of cladding layers significantly.The hardness of the cladding layer with 3.0% Cr reached 1090HV0.2.The weight loss of cladding layer was only about 1/26of Q235steel under the same abrasive wear condition.When the addition of Cr was 9.0%,the cladding layer showed the best corrosion resistance and its corrosion resistance was about 3.26times than that of the cladding layer without Cr.