In order to increase yield strength of commercial microalloyed steel from 400MPa to 800MPa, grain refinement and high purity are taken into consideration.

• 为了将目前商业化微合金钢的屈服强度由40MPa级提高到800MPa级；拟采用超细晶粒和高洁净度的方法来提高强度和寿命.