一、避免铸造应力一个铸件不同部分的冷却速度的差异往往是造成铸造应力的原因。由于金属凝固时收缩不均或收缩受阻而造成裂纹、变形以及其它结构缺陷。一个铸件从开始凝固直至冷却到室温的过程中,最初一直是收缩,但到碳化物临界转变时则出现显著的膨胀现象,然后又继续正常收缩。因此,为了减少以至消除铸造应力,必须: 1.避免沿铸件收缩方向出现突然的形状改变。 2.避免凹入角。 3.避免使用过多的泥芯——因为泥芯聚集太多,遇热时铸件会有很大的 First, to avoid casting stress Casting different parts of a cooling rate of the difference is often the cause of casting stress. Due to uneven metal shrinkage or shrinkage caused by solidification cracks, deformation and other structural defects. During the initial solidification of a casting until it cooled to room temperature, the initial shrinkage was followed by a significant expansion until the critical carbides transitioned to normal shrinkage. Therefore, in order to reduce and eliminate the casting stress, you must: 1. Avoid sudden changes in shape along the casting shrinkage direction. Avoid concave angle. 3. Avoid using too much mud core - because mud core aggregation too much, when the castings will have a lot of heat