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研究比较了不同低膨胀高温合金在模拟海洋盐雾环境中的耐腐蚀性能和表面沉积盐对不同低膨胀高温合金高温抗氧化性能和力学性能的影响。试验结果发现:在35℃模拟海洋盐雾环境下,GH907、GH909和GH929C低膨胀高温合金的耐腐蚀性能比较差,在16小时开始锈蚀,到258小时的平均腐蚀速率约为0.01-0.05 g/m2·h。GH783合金在50小时开始出锈,且为点蚀,到500小时的平均腐蚀速率在0.009-0.011 g/m2·h之间。GH242合金到550小时后仍不出锈。盐雾环境在合金表面产生的沉积盐对Fe-Ni-Co基低膨胀高温合金的高温氧化速率有显著的促进作用。在550-700℃,表面沉积盐使GH907和GH909合金高温氧化速率的提高为GH783和GH242合金的2-4倍。表面沉积盐引起合金表面氧化速率的提高使GH907和GH909合金在650℃的拉伸强度和持久寿命显著降低。
The effects of different low-expansion superalloys on corrosion resistance and surface deposition of salt in high-temperature oxidation resistance and mechanical properties of low-expansion superalloy were compared. The results showed that the corrosion resistance of GH907, GH909 and GH929C low-expansion superalloy was poor at 35 ℃ simulated sea salt fog environment, and corrosion started at 16 hours. The average corrosion rate at 258 hours was about 0.01-0.05 g / m2 · h. The GH783 alloy started rusting at 50 hours and was pitting corrosion with an average corrosion rate of 0.009-0.011 g / m2 · h at 500 hours. GH242 alloy does not rust after 550 hours. The depositional salt produced on the alloy surface in salt spray environment can promote the high temperature oxidation rate of Fe-Ni-Co based low-expansion superalloy. Surface deposition of salts at 550-700 ° C increased the high temperature oxidation rate of GH907 and GH909 alloys by 2-4 times higher than that of GH783 and GH242 alloys. Surface deposition of salt caused by the alloy surface oxidation rate of GH907 and GH909 alloy at 650 ℃ tensile strength and long-life significantly reduced.