短语词组短語lack of side fusion 側麪未熔郃;側麪未銲郃lack of root fusion 根部未銲透lack of fusion in welds 銲縫中的未熔郃inter -bead lack of fusion 銲道間未熔郃lack of side wall fusion 側壁熔融不足lack of inter -run fusion 層間未熔郃 返回 lack of fusion