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本文着重研究了内燃机排气阀的热腐蚀疲劳破坏机理,并指出采用真空熔结合金涂层是解决这一问题的有效方法。为了全面讨论热腐蚀与疲劳应力的联合破坏作用,也适当研究了预燃室喷嘴的破坏机理与合金涂层的保护作用。以喷射盐水溶液的“HCF”全自动热腐蚀疲劳直接对比试验法,研究了 4Cr10Si_2Mo、18SR、20-14三种耐热钢与 Co-50、Ni-81两种合金涂层的抗热腐蚀疲劳性能。腐蚀程度的测量由试样的最大腐蚀深度来决定。并以金相、电子探针和 X 光衍射技术研究了各钢种的热腐蚀疲劳破坏过程,和两种合金涂层有效地抗热腐蚀疲劳的原因。
This paper focuses on the thermal corrosion fatigue failure mechanism of the exhaust valve of an internal combustion engine, and points out that the use of vacuum fusion bonding alloy coating is an effective way to solve this problem. In order to comprehensively discuss the combined destructive effect of hot corrosion and fatigue stress, the destructive mechanism of pre-combustion chamber nozzle and the protective effect of alloy coating are also properly studied. In this paper, direct corrosion test of “HCF” sprayed brine solution was used to study the thermal fatigue resistance of three kinds of alloy coatings of 4Cr10Si_2Mo, 18SR, 20-14 and Co-50 and Ni-81 performance. The degree of corrosion is measured by the maximum depth of corrosion of the specimen. The hot corrosion fatigue failure process of all kinds of steel and the reasons of the effective anti-hot corrosion fatigue of the two alloy coatings were studied by metallography, electron probe and X-ray diffraction.