【摘要】 采用药芯焊丝埋弧堆焊方法制备含有C 1.2%~1.8%(质量分数,下同),Cr 15%~20%,V 2.0%~3.0%,B0%~1.0%的高铬堆焊合金。借助光学显微镜、扫描电镜和X射线衍射等分析手段,研究其显微组织及碳化物分布形貌,结果表明:其显微组织由α-Fe+-γFe+(Fe,Cr)7C3+(Fe,Cr)3C+Fe3(C,B)+B4C等组成,加入B4C可显著细化该堆焊合金晶粒,降低-αFe,-γFe基体组织的Cr,V等合金元素的固溶量,使碳化物(Fe,Cr)7C3数量增加且呈弥散分布。另外,考察了B4C含量对高铬堆焊合金硬度及耐磨性的影响,耐磨粒磨损实验结果表明其相对磨损系数是H25Cr3Mo2MnV堆焊合金的6~17倍,其中碳化物颗粒四周均匀分布的-αFe等基体组织使其可承受较大的磨粒冲击而不脱落。更多还原

【Abstract】 High-chromium hardfacing alloys containing 1.2%-1.8%C,15%-20%Cr,2.0%-3.0%V and 0%-1.0%B(mass fraction) were deposited by the method of flux-cored wire submerged arc welding.The microstructure and carbide morphology were investigated by optical microscopy(OP),scanning electron microscopy(SEM) and X-ray diffraction(XRD).The results show that the microstructure consists of α-Fe,γ-Fe,carbide such as(Fe,Cr)7C3,(Fe,Cr)3C and boride such as Fe3(C,B),B4C etc.The addition of B4C powders results in grain refinement and Cr,V content in the solid solution matrix decreased,which made the volume fraction of(Fe,Cr)7C3 increase.The effects of B4C in flux-core wire on hardness and wear resistance were evaluated and the experimental results demonstrated that its relative coefficient was 6-17 times of solid wire H25Cr3Mo2MnV.Dispersed carbide which was surrounded by α-Fe matrix can suffer stronger attacking of abrasive particles without pulling off.更多还原