X20Cr13钢的晶粒度测定及其抗氧化性能研究

Measurement of Grain Size and Research of Oxidation Resistance of X20Cr13 Steel

耐热钢的晶粒度及其抗氧化性能在一定程度上决定了其在实际服役过程中的安全性。对汽轮机组用X20Cr13钢的晶粒度进行测定并对其抗氧化性能进行了研究。结果表明:X20Cr13钢的晶粒度为5.2级,符合汽轮机组用材料的技术要求。热重及同步热分析结果表明:在566~650℃保温3 h后,试样质量未发生明显变化,且未发生明显的相变。氧化试验结果表明:在620℃保温不同时间(25~125 h)时,随着保温时间的延长,试样表面的氧化物逐渐增多并聚集长大成层片状,但总体数量仍相对较少,说明X20Cr13钢的抗氧化性能优异。

Safety in actual service of the heat resistant steel depends on its grain size and oxidation resistance to some extent. The grain size measurement and oxidation resistance test of X20 Cr13 steel used in steam turbine were carried out. The results showed that the grain size of X20 Cr13 steel was grade 5. 2,which could meet the technical requirements for the material used in steam turbines. The simultaneous thermogravimetry-differential thermal analysis results indicated that there was no significant change in mass and no obvious phase transition occurred in the samples after holding at 566 to 650 ℃ for3 h. The oxidation resistance test revealed that with the increase of holding time( 25 to 125 h) at 620 ℃,the oxides on sample surface gradually increased and aggregated into lamellae in shape,but their amount was relatively small,indicating that X20 Cr13 steel had excellent oxidation resistance.