Cr3C2/镍基合金等离子堆焊层的组织及耐磨性能

采用光学显微镜、扫描电镜、X射线衍射仪以及磨损试验机等,研究了加入不同量的Cr3C2对等离子堆焊镍基合金堆焊层组织和耐磨性能的影响.结果表明:纯镍基合金堆焊层组织主要是由γ(Ni,Fe)、CrB和M7(C,B)3等物相构成,且存在着明显的成分偏析;加入Cr3C2以后,合金层中出现了Cr3C2相,且使堆焊层枝晶破碎,组织变细,成分偏析减弱直至消失;Cr3C2颗粒的加入,提高了堆焊层的磨粒磨损性能,且随其加入量的增加,耐磨性逐渐提高;当加入量达到30%时,耐磨性最好,随后耐磨性开始降低.

Microstructure and Wear Resistance of Cr3C2/Ni Composite Coating Deposited by Plasma Transferred Arc Surfacing

The nickel-based alloys with different Cr3C2 contents had been deposited by means of a plasma transferred arc (PTA) welding machine. The effects of Cr3C2 on the microstructure and wear resistance of the nickel-based alloy coatings were investigated using various techniques, including optical microscopy, SEM, XRD and dry sand abrasion test (DSAT). The Cr3C2-free nickel-based alloy coating is composed of y(Ni,Fe), CrB and M7 (C,B)3. The composition segregation exist in this coating. The addition of Cr3C2 particles led to the existing of Cr3C2 phase. The dendrites in the Cr3Cz-free coating are broken, which led to the refinement of the Cr3C2-modified coatings. The addition of Cr3 C2 particles led to the decreasing of the composition segregation till final disappearance. The wear resistance is improved because of the addition of Cr3 C2 particles. The wear resistance increase with the increasing of Cr3C2 contents from 0% to 30%. However, further increasing its content led to the decreasing of the wear resistance.