It turns out that crack closure is the main reason for retardation, and crack tip blunting, crack deflection and strain-induced martensite would reinforce it.

• 室温蠕变对裂纹扩展产生延滞的原因主要是裂纹闭合,同时裂尖钝化、裂纹偏折及形变诱发马氏体的形成也会起到一定的作用。