The phenomenon of HIC happened in NACE solution (5%NaCl+0.5%acetum,pH=3.5),and the banded structure (P+F) along the interface of inclusion/substrate and the rolling direction induced stepwise cracking.

• 管线钢在NACE试验介质中发生了氢致开裂 (HIC) ,沿夹杂物 /基体界面及轧制方向的 (珠光体 +铁素体 )带状组织导致了台阶状裂纹 ;