Galling resistance of hardfacing alloys replacing Stellite
Galling resistance of hardfacing alloys replacing Stellite
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替代司太立合金的硬面合金的抗磨损性
DOI：
10.1016/0043-1648(94)90232-1
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发表时间：
1994
期刊：
影响因子：
5
通讯作者：
Jussi Vikström
中科院分区：
文献类型：
--
作者：
Jussi Vikström
传统上，钴相合金被用作核电站阀门、涡轮机和泵的堆焊材料，因为它们通常在滑动条件下表现出高耐腐蚀性和优异的摩擦学性能。在核电站中，由于阀门和泵的磨损，钴被输送到反应堆核心区。在那里，钴被转化为反应性的60Co，增加了辐射水平。本工作的目的是寻找一种耐磨性优于或等于广泛使用的钴基合金Stellite 6的无钴堆焊材料。将6种铁基和4种镍基合金与Stellite 6进行了比较。采用等离子转移弧焊(PTAW)、钨极气体保护焊(GTAW)、等离子喷焊和激光熔化等方法在奥氏体不锈钢表面沉积了合金。其中一种合金处于热等静压(HIP)状态。合金在室温、平均压力为140、275和415兆帕的空气中进行了耐刮擦性能测试。并对合金的组织和硬度进行了研究。使用扫描电子显微镜、光学显微镜和显微硬度测量对测试后的表面进行了检查。自配铁基Elmax、APM 2311、Norem A、NelSite、Everit 50 SO合金和Ni/Fe基合金组合表现出比Stellite 6更好的抗刮擦性能，特别是Elmax和APM 2311合金表现出极高的抗刮擦性能。表面不是被刮伤，而是由脆性机制造成的裂缝。这可能会导致广泛的裂纹扩展，最终导致大规模的表面退化。镍基Deloro合金的抗刮擦性能不如Stellite 6。由于本研究所研究的合金具有非常不同的显微组织特征，因此任何抗刮削性能与组织特征之间的关联都是非常不准确的。此外，还观察到抗刮擦性能与镀层的硬度无关，高应力刮削试验引起的硬度增加幅度为150-200HV，与试验前的硬度无关。
Cobalt-phase alloys have traditionally been used as hardfacing materials for nuclear power plant valves, turbines and pumps, since, in general, they show high corrosion resistance and superior tribological behaviour under sliding conditions. In nuclear power plants cobalt is transported to the reactor core region due to wear of valves and pumps. There cobalt is transmuted to reactive60Co, increasing the radiation levels. The objective of this work was to find a cobalt-free hardfacing material having a wear resistance better than or equal to the widely used cobalt-base alloy Stellite 6. Six iron-base and four nickel-base alloys were compared to Stellite 6. Alloys were deposited on austenitic stainless steel by plasma transferred arc welding (PTAW), gas tungsten arc welding (GTAW), plasma spray fuse and laser processes. One alloy was in hot isostatic pressed (HIP) condition. Alloys were tested for galling resistance in air at room temperature at mean pressures of 140, 275 and 415 MPa. Also the microstructure and hardness of the alloys were investigated. Post-test surfaces were examined using scanning electron and light microscopy and microhardness measurements. Self-mated iron-base Elmax, APM 2311, NOREM A, Nelsit, Everit 50 So alloys and Ni/Fe-base alloy combination showed better galling behaviour than Stellite 6. In particular, Elmax and APM 2311 alloys showed extraordinary high galling resistance. Instead of galling, the surface cracks by a brittle mechanism. This may lead to extensive crack propagation and finally large scale surface degradation. The nickel-based Deloro alloys showed a galling resistance inferior to Stellite 6. Since the alloys investigated in this study have very different microstructural characteristics, any correlation between galling resistance and microstructural features would be very inaccurate. Further, it was observed that the galling resistance was not related to the hardness of the deposit and, the increase in hardness caused by the high stress galling test is of the magnitude of 150–200 HV, independent of the pre-test hardness.