A.兩個(gè)缺陷當(dāng)量相同 B.材質(zhì)衰減大的鍛件中缺陷當(dāng)量小 C.材質(zhì)衰減小的鍛件中缺陷當(dāng)量小 D.以上都不對(duì)
A.40% B.20% C.10% D.5%
A.底面回波 B.底面二次回波 C.缺陷回波 D.遲到回波