压铸机用镁液坩埚失效分析

Failure Analysis of Crucible Used in Hot Chamber

摘要: 镁合金热室压铸机所用坩埚在使用3～4个月后在靠近外焰的底部和侧面结合处发生严重的变形开裂,对开裂原因进行了分析.结果表明:开裂的主要原因是坩埚在使用过程中沿横截面存在温度梯度;温度过高的外表面在奥氏体化过程中产生了拉应力,同时表面存在脱碳使强度降低,最终在该拉应力的长期作用下坩埚表面开裂直至报废.

Abstract: After been used for 3-4 months,the crucible had serious crack at the joint of the bottom and side closing to the outer flame.Its analyzed that the temperature gradient along cross section causes the crack.The outer surfaces temperature is too high,so that the stress in the process of austenization,and the surface losing carbon makes the intensity decrease,eventually,the crucible cracked.