激光熔覆Ni/Cr_3C_2的组织及冲蚀磨损性能

借助x射线衍射仪、扫描电镜、x射线能谱仪和浆罐式冲蚀磨损试验机，研究了在2Crl3马氏体不锈钢基村上经激光熔覆Ni／Cr3C2／（Ni＋Cr）复合涂层的组织与冲蚀磨损性能。研究试验结果表明，Cr3CZ粒子的加入及完全溶解，增加了熔池中Cr和C的含量，使合金在冷凝时析出M7C3化合物。强化表面合金层由细密的奥氏体校晶和技晶间的v－M7C3共晶体组成，并且随Cr3C2粒子含量的增加，熔覆层的枝晶组织细小，硬度增高，其显微硬度可达350－450HV，比2Clr3钢基村的硬度（约220HV）提高约1倍。在酸性砂浆水溶液扣十击角固定在45，在7－9．5m／S冲击速度下，用Ni＋50％CY3CZ强化的熔覆层冲依磨损率比2Cr13钢基材的减小约50％。

Microstructure and erosion resistance of Ni/CrC_2/(Ni Cr) cladded by laser

By means of x-ray diffraction apparatus, scanning electronic mocroscopy, x-ray energy spectrum meter and erosiontester, the microstiucture and properties of Ni/Cr3C2,/(Ni Cr) composite layer cladded by laser on 2Crl3 martensiticstainless steel n1atrix are imyestigated. Test results show that, adding and complete dissolving of Cr3C2 partic1es increasethe content of Cr and C in the molten bath, and result in the separation of M7C3 compounds during solidification of the alloy. -Yhe hardened surfaces are composed of dense austenite(Y) dendrites surmunded by a Y-M7C3 eutectic, and the dendntes are fine and d1eir hardness values increase 1vitLh the increase of the content of C1trC2 particles in the clad layer. Themicrohardness of the ha1dened su1fi1ces is twice as large as 2Crl3 steel. in the acid sandy slurry, under the condition ofa fixed impact of 45" and a impact velocit of 7 ~ 9 .5m/s, the clad layer is stiengthened by Ni 5O% Cr3C2, and itserosion late is leduced by about 50% compared with that of 2Crl3 matrix.