钛合金在高温高压过热蒸汽中的腐蚀机理研究

Study of Corrosion Mechanism under High Temperature and Pressure Watersteam with Overheating for Titanium Alloy

研究了T225NG和T42NG合金在高温、高压、过热蒸汽中长时间的氧化腐蚀规律。对试样表面氧化膜元素、相组成及表面形貌进行了测试与分析,给出了两种合金的腐蚀动力学模型,并对两种合金的腐蚀机理进行了初步分析。结果表明,两种钛合金中主元素Ti优先产生氧化腐蚀,合金元素Al和Fe及N、H、C等杂质元素对腐蚀起到促进作用,并在合金表面呈现出典型的结晶学特征。两种钛合金的腐蚀动力学规律均服从Wagner理论中的近抛物线规律。

This paper has studied the regular pattern of oxidization corrosion of T225NG and T42NG [(t)0(it)]anium alloy under high-temperature and high-pressure with long time. The element of the oxide film on surface, constitution and microstructures have been tested and analyzed, and the model of corrosion dynami-cal for T225NG and T42NG alloys has been[( )-136.5(obtai)]ned. The same time, the corrosion mechanism has been analyzed briefly .The results indicate that the main element Ti oxides first, and element Al and the impurity elements such as Fe, N, H, C promote corrosion behavior. All of this shows typical crystallographic character. The corrosion dynamics pattern of these two alloys all submits Para-curve in Wagner theory.