| 摘要: |
| 针对再制造大型热轧支承辊堆焊层的服役早期开裂现象,通过检测分析堆焊层硬度、显微组织和断口形貌,确定堆焊层开裂失效机制是低周接触疲劳破坏。由于堆焊层内残余奥氏体含量过多,马氏体相含量相对不足,堆焊金属低硬度、低强度,降低了再制造热轧支承辊面堆焊层的抗接触疲劳性能。通过高温回火热处理促使堆焊层残余奥氏体向马氏体转变,调控辊面堆焊层亚稳相残余奥氏体和马氏体含量,提高再制造支承辊面硬度、强度,可有效避免服役期内再制造热轧支承辊面堆焊层开裂现象,从而提高再制造大型热轧支承辊的质量稳定性和使用寿命。 |
| 关键词: 再制造 大型热轧支承辊 堆焊层 残余奥氏体 裂纹 |
| DOI：10.11951/j.issn.1005-0299.20210188 |
| 分类号:TG405 |
| 文献标识码:A |
| 基金项目: |
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| Failure analysis of cracked surfacing layer of remanufactured large hot-rolled backup roll |
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NIE Binying
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(Chemical and Biological Engineering College, Yichun University, Yichun 336000,China)
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| Abstract: |
| In order to investigate the cracking failure mechanism of surfacing layer on the remanufactured large hot-rolled backup roll at the early stage of service, the hardness, microstructure, and fracture morphology of surfacing layer were characterized and analyzed. The research results confirmed that the cracking failure mechanism of surfacing layer was low-cycle contact fatigue failure. Since the content of residual austenite was too high and the content of martensite phase was relatively insufficient in the surfacing layer, the hardness and strength of the surfacing metal were lower, which reduced the contact stress fatigue resistance of the surfacing layer of remanufactured hot-rolled backup roll. The high-temperature tempering heat treatment was adopted to promote the transformation of residual austenite to martensite in the surfacing layer, which could effectively control the content of residual austenite and martensite in the surfacing layer on the roll surface, enhance the hardness and strength of the surfacing layer on the roll surface, avoid the cracking of the surfacing layer, and thus improve the quality stability and service life of remanufactured large hot-rolled backup roll. |
| Key words: remanufacturing large hot-rolled backup roll surfacing layer residual austenite crack |
