摘要
以纳米和微米级的W Fe/C复合粉末为主要原料制备了D707药皮焊条。用扫描电镜、X射线衍射、硬度等对堆焊层的显微组织、相组成、化学成分、硬度进行了分析。结果表明,纳米焊条堆焊层的组织中碳化物大多呈细小块状,组织由大量的碳化物(Fe3W3C)、奥氏体和少量的马氏体组成;而微米焊条堆焊层的组织中碳化物大多呈粗大树枝状,成分偏析严重,组织由大量的碳化物(Fe3W3C)和奥氏体组成。两种焊条堆焊层碳化物中的W含量分别为71.78%和64.75%,说明前者合金元素过渡较好。纳米焊条堆焊层硬度高于微米焊条堆焊层,可达61.5HRC,回火后硬度最高可达65HRC。
The D707 welding rods were fabricated with the nanostructured and microsized WFe/C composite powders as main starting materials. The scanning electronic microscope, Xrays diffraction and hardness test were used to analyze the microstructures, chemical and phase compositions and hardness. The results showed that the carbides in the microstructures welded with nanostructured powder rods (NPR) were granular and fine, and the most carbides in the microstructures welded with microsized powder rods (MPR) were dendritic, coarse, and severe in compositional segregation. The contents of element W in the carbide welded with NPR and MPR were 71.78% and 64.75%,respectively, which showed that the alloy element transition of the former was better than that of the latter. The microstructure welded with NPR consisted of numerous Fe3W3Ctype carbides, austenite and a small quantity of martensite. And that welded with MPR was composed of numerous Fe3W3Ctype carbides and austenite. The hardness of layers welded with NPR was 61.5HRC aswelded and 65HRC astempered, all of these were higher than that welded with MPR.
出处
《机械工程材料》
CAS
CSCD
北大核心
2003年第2期25-27,36,共4页
Materials For Mechanical Engineering
基金
辽宁省科学技术基金资助项目(9910300503)
关键词
纳米粉末
焊条
显微组织分析
nanostructured composite powder
welding rod
microstructure analysis
