牙轮钻头强化用YQ4堆焊层组织性能研究

利用自主开发NiCrBSiCu合金粉研制了YQ4堆焊焊条，采用氧乙炔堆焊工艺制作了堆焊试样，利用剪切实验测试了堆焊层强度，冲击磨料磨损实验测试了试样的耐磨性，利用扫描电子显微镜观察了断口显微组织特征。实验结果表明：YQ4硬质合金堆焊层中过渡层组织细小，耐磨层中脆性硬质合金相上均匀分布了韧性微孔结构低熔点合金，硬质合金分布致密、均匀、多层堆垛，基体与过渡层以及硬质合金之间结合良好，平均剪切强度600MPa，高于牙轮钻头工作要求，抗冲击磨料磨损能力提高近2倍，在组织与性能上都满足牙轮钻头齿面强化要求

MICROSTRUCTURE AND PROPERTIES OF HARDFACING COATING ON TOOTH CONE BIT BY USING YQ4

By adding self-developed Ni-Cr-B-Si-Cu alloy powder，the YQ4 surfacing welding electrode is prepared，and the samples are made with Oxyacetylene welding process.The shear strength of surface layer and the wear resistance of impact abrasive wearing is tested，the microstructure of the fracture is investigated with scanning electronic microscope (SEM).The results show that the microstructure of transition layer of YQ4 cemented carbide surfacing layer is fine，the tough low melting point alloy with microporous structure is uniformly dispersed on the brittle carbide phase，and the cemented carbide distributes compact and homogeneous as well multilayer stacking.The substrate and transition layer combines effectively with the cemented carbide.The 600MPa shear strength is higher than the requirements of the cone bit，the impact abrasive wearing resistance is improved almost 2 times，and the microstructure and properties meet the requirements of the steel tooth cone bit.