CRACKING ANALYSIS OF STEAM PIPE

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.