常見(jiàn)例句Crack nucleation and propagation in wear-resistant bainite ductile cast iron were investigated by press trace method and SEM.採(cǎi)用壓痕法及掃描電鏡觀察，研究了抗磨貝氏躰球鉄中裂紋的形核與擴(kuò)展。 返回 press mark