蒸汽管材料为15CrMoG,设计寿命为15~20 a(年),使用一年半后发生了爆裂,现场调查表明蒸气管有超温使用现象。通过化学成分分析和常温力学性能分析表明蒸气管用料符合技术要求。金相分析结果表明蒸汽管有蠕变空洞和珠光体球化现象,高温瞬时力学性能试验结果表明蒸汽管于705 ℃时力学性能已明显降低,断口宏观检验和断口微观分析均表明该蒸汽管爆裂具有超温爆裂特征。

The steam pipe was cracked by one and a half year after plunged in use,whose expected service life should be 15~20 years and the materials was 15CrMoG. It was proved that the pipe was used in super temperature condition according to the spot survey. The analysis showed that the chemical composition and mechanics properties of materials met that the technology standard stated. The creep hole and g metallographic examination implied that sphere shape pearlite was formed. The high temperature mechanical properties dramatically dropped at a temperature of 705 ℃. And the fracture analysis showed that the fracture was a kind of crack character.