单项选择题
A.〈1.5倍B.〉1.5倍C.≤1.5倍D.≥1.5倍
A.±0.015H0,最小士0.3B.±0.020H0,最小士0.4C.±0.030H0,最小土0.6D.±0.040H0,最小土0.8
A.时效B.正火C.去应力退火等工D.回火