煤化工装备中关键阀内件的失效行为及表面强化技术

The failure behavior and surface strengthening technology of valve trims in coal chemical industry equipment

针对煤化工装备中关键阀内件材质的劣化问题,采用宏/微观多尺度分析方法研究在不同服役工况下阀内件的失效风险因素,并提出阀内件表面的强化策略。结果表明:气-固稀相介质下阀内件失效行为是气-固两相冲蚀导致材料流失;气-固浓相介质下阀内件失效是气相和固相煤粉冲蚀、颗粒及黏着磨损等多种因素耦合,冲蚀所占比例较大;液-固介质下失效机理是腐蚀、冲蚀、磨损等多种因素耦合。基于阀内件失效风险,并结合材质的强-塑-韧适配性原理,提出了多功能一体化涂层的防控策略。通过超音速等离子喷涂技术在基体表面制备Ni Cr-Cr_(3)C_(2)金属-陶瓷涂层,涂层结构致密,硬度提高至HV_(0.3)1013。相比不锈钢材质,涂层硬度提高近5倍。拉伸测试表明,Ni Cr-Cr_(3)C_(2)涂层与基体结合强度达到67 MPa,且耐冲击性能优异,实现了材质表面的强化。

In view of the deterioration of the material of key valve internal parts in coal chemical equipment,the macro-micro multi-scale analysis method was used to study the failure risk factors of valve trims under different service conditions,and surface strengthening strategy for valve trims was proposed.The results show that in the gas-solid dilute phase medium,the material loss caused by gas-solid two-phase erosion leads to the valve trim failure;In gas-solid dense phase medium,the coupling of multiple factors such as pulverized coal erosion,particle and adhesive wear leads to the valve trim failure,and erosion is the main factor.In liquid-solid medium,the coupling of corrosion,erosion,wear and other factors leads to the valve trim failure.Based on failure risk of key valve trims and in combination with the principle of strength-plasticity-toughness adaptability of materials,a failure prevention and control strategy of multi-functional integrated coatings was proposed.NiCr-Cr_(3)C_(2) metal-ceramic coatings on the substrate surface were prepared by supersonic plasma spraying technology.The morphology of the coating displayed dense structure and the hardness was increased to HV_(0.3)1013.Compared with the hardness of stainless steel,the hardness of the coating was increased by nearly 5 times.The tensile testing of bonding between the coating and the substrate shows that the strength reaches 67 MPa and the excellent impact resistance performance,thus realizing the reinforcement of materials surface.