The results indicated that the steel is composed of quasi bainite, lath martensite and twin martensite under air cooling condition, and also has better combination of strength and toughness.

• 试验表明:该钢空冷条件下即可获得准贝氏体、板条马氏体及孪晶马氏体的复合组织,且具有较好的强韧性配合。