甲:老王,最近我厂铸件不断出现皮下气孔缺陷。它的直径为1～3毫米,形状象个灯泡,用针可以刺入,也有人叫它针孔。这种缺陷讨厌的是在落砂清理铸件后并不能被发现,往往在退火和喷丸清理后,甚至在经机加工后才被暴露。你想,费了那么多的力气, A: Pharaoh, I plant the recent emergence of subcutaneous pneumoperitoneum defects. Its diameter is 1 ~ 3 mm, the shape of a light bulb, needle can pierce, but also some people call it a pinhole. The drawback of this defect is that it can not be found after the sand is removed from the casting and is often exposed after annealing and shot peening, even after machining. You think, spent so much effort,