Cause Analysis on Cracking of X52 Pipeline Steel in Hydrogen Induced Cracking Resistance Test

Aiming to sovle the problem of appearing obvious stepwise cracking of X52 pipeline steel products in certain period of the anti ladder type cracking test, the chemical compositions, steel making process, and microstructure of the cracking batch samples were analyzed, and the cracking reasons of the pipeline steel in hydrogen induced resistance test were analyzed. The results show that the lower calcium sulfur content ratio of the cracking batch samples resulting in gathering of inclusions and center segregation and linear distribution of the inclusions were the main cracking cause of the X52 pipeline steel. Finaly corresponding proposals to production control points were put forward to improve the hydrogen sulfide stress corrosion resistance of X52 pipeline steel.