两种Ni-Cr-B-Si系合金等离子堆焊层组织结构和显微硬度的研究  

Study on Microstructure and Microhardness in PTA Weld Hardfacings of Two Types of Ni-Cr-B-Si Alloys

作　　者：葛言柳[1] 邓德伟[1] 鲁俊[1] 田鑫[2] 关锰[2] 

机构地区：[1]大连理工大学材料科学与工程学院,大连116024 [2]沈阳鼓风机(集团)有限公司,沈阳110869

出　　处：《表面技术》2012年第1期5-8,19,共5页Surface Technology

基　　金：国家自然科学基金(11072045);国家973课题(2011CB013402)

摘　　要：采用等离子堆焊技术在304L不锈钢表面堆焊Ni-Cr-B-Si合金粉末熔覆层。应用扫描电子显微镜、电子探针、X-射线衍射仪、显微硬度计等测试手段,研究两种Ni-Cr-B-Si系合金成分等离子堆焊层组织结构和显微硬度。结果表明:堆焊合金层组织由γ-Ni树枝晶和树枝晶间多元共晶组成;Cr,C,B和Si元素含量增加,树枝状组织含量大幅减少,碳化物和硼化物含量显著增加。硬度测试结果表明:硼化物和碳化物含量增大使得堆焊层硬度显著提高。The Ni-Cr-B-Si alloy powder was deposited on the surface of 304L stainless steel by plasma transferred arc welding（PTAW）. To determine the microstructure and properties of hardfacings with two types of alloys, scanning electron microscope, X-ray diffraction, electron microprobe and hardness tester were employed. The results show that the coatings consist of y-Ni dendrites and eutectic mixture as interdendritic constituents. It is found that the content fraction of the dendritic phases drastically decreases and the proportion of chromium borides and carbides increases with an increase of Cr, C, B and Si content. Microhardness testing reveals that an increase in content of chromium borides and carbides leads to a significant increase of hardness.

关 键 词：等离子堆焊 Ni—Cr—B—Si 显微组织 硬度 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG456.2[金属学及工艺—金属材料]