消除铸件,焊接件及机加工件残余内应力,应在精加工或淬火前进行的退火方式是() ["扩散退火","去应力退火","球化退火","完全退火"]
在镗孔系统刚性不足时,应增大镗刀主偏角,减小(),这样可减小径向力,提高镗孔精度。 ["A、刀尖圆角半径","B、副偏角","C、前角","D、后角"]
焊接时,焊缝坡口钝边过大,坡口角度太小,焊根未清理干净,间隙太小会造成()缺陷 ["气孔","焊瘤","未焊透","凹坑"]
加工台阶零件前,刀架不垂直,龙门刨床横梁溜板紧固螺钉未拧紧而让刀,导致阶台两侧面不()。 ["A、平行","B、同轴","C、对称","D、垂直"]
焊丝表面镀铜是为了防止焊缝中产生() ["气孔","裂纹","夹渣","未熔合"]
比转速