Abstract A graded surfacing layer for repairing a failed mandrel was prepared on the surface of H13 steel using the homemade flux-cored wires via submerged arc welding technology. The microstructure of the designed surfacing layer was controlled by modifying its chromium content based on the Fe-Cr binary phase diagram. The as-welded microstructure, phases, chemical composition, microhardness and wear resistance of the resultant surfacing layer were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), direct reading spectrometry, Vickers hardness testing and dry sliding wear testing. These results showed that the surfacing sample could be divided into seven zones based on cross sectional micrographs of the substrate, sublayer, wear layer and four fusion zones. The sublayer consists of a large amount of ferrite, lower bainite and carbides, which showed the lowest microhardness of 237 HV0.2. The wear layer was composed of martensite, lower bainite, residual austenite and carbides with a microhardness of 356 HV0.2 that was 80 HV0.2 higher than that of the H13 steel substrate. The weight loss of the H13 steel substrate after wear testing for 20 min was 25.3 mg, which was around 1.7 times that of the wear layer (15.1 mg), whilst wear scar with smaller width and depth was observed on the surface of the wear layer. This indicates that the wear resistance of the wear layer was better than for the H13 steel substrate. No appreciable cracks were observed in the four fusion zones after the surfacing process, suggesting that good fusion had occurred between the H13 steel substrate, sublayer and wear layer.

中文翻译：

---

使用埋弧焊技术制造用于修复失效 H13 芯棒的渐变堆焊层

摘要 采用国产药芯焊丝，采用埋弧焊技术，在H13钢表面制备了用于修复失效芯棒的梯度堆焊层。通过基于 Fe-Cr 二元相图修改其铬含量来控制设计的堆焊层的微观结构。使用光学显微镜（OM）、扫描电子显微镜（SEM）、X射线衍射（XRD）、直读光谱、维氏硬度分析所得堆焊层的焊态组织、物相、化学成分、显微硬度和耐磨性试验和干滑动磨损试验。这些结果表明，根据基材、亚层、耐磨层和四个熔合区的横截面显微照片，堆焊样品可分为七个区域。次层由大量铁素体、下贝氏体和碳化物组成，显微硬度最低，为 237 HV0.2。磨损层由马氏体、下贝氏体、残余奥氏体和碳化物组成，显微硬度为 356 HV0.2，比 H13 钢基体的显微硬度高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。下贝氏体和碳化物，其显微硬度最低，为 237 HV0.2。磨损层由马氏体、下贝氏体、残余奥氏体和碳化物组成，显微硬度为 356 HV0.2，比 H13 钢基体的显微硬度高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。下贝氏体和碳化物，其显微硬度最低，为 237 HV0.2。磨损层由马氏体、下贝氏体、残余奥氏体和碳化物组成，显微硬度为356 HV0.2，比H13钢基体高80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。其显微硬度最低为 237 HV0.2。磨损层由马氏体、下贝氏体、残余奥氏体和碳化物组成，显微硬度为 356 HV0.2，比 H13 钢基体的显微硬度高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。其显微硬度最低为 237 HV0.2。磨损层由马氏体、下贝氏体、残余奥氏体和碳化物组成，显微硬度为 356 HV0.2，比 H13 钢基体的显微硬度高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。残余奥氏体和碳化物的显微硬度为 356 HV0.2，比 H13 钢基体高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。残余奥氏体和碳化物的显微硬度为 356 HV0.2，比 H13 钢基体高 80 HV0.2。H13钢基体经过20 min磨损试验后的重量损失为25.3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕. 这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕。这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。3 mg，约为耐磨层（15.1 mg）的1.7倍，同时在耐磨层表面观察到宽度和深度较小的磨痕。这表明耐磨层的耐磨性优于 H13 钢基体。堆焊后四个熔合区均未观察到明显裂纹，表明 H13 钢基体、亚层和耐磨层之间发生了良好的熔合。