珠光体耐热钢焊接过程中,靠近熔合线的热影响区被加热到1300°C以上,此时钢中的( )等元素从碳化物溶入固溶体,当焊接接头再次被加热时,碳化物从固溶体中析出,使焊缝晶粒强化,在焊接应力松弛过程中,晶界处发生蠕变,导致产生再热裂纹。 A. C.Mg B. Mo、Cu、C C. Ag、C.Mg、Cu D. Cr、Mo、V、Ni、Ti
【简答题】Which of the following is NOT the secret of the couple's successful marriage? [A] Don't go to sleep on an argument. [B] Always kiss each other before going to bed. [C] Always hold hands each other whe...