在谈到磷对铸件热裂的影响时,通常认为磷量过高,会形成低熔点的磷共晶(Fe-Fe_3P),降低固相线的温度,当铸件收缩受阻时,易形成热裂。因而,磷是一种有害元素。那么,当磷量过低时,会出现什么情况呢?事实上,磷量过低时,铸件也会出现热裂。我厂生产的主轴承盖是供东风EQ 140汽车装车用的,材质为HT 20-40,其尺寸见图1,工艺图见图2。该产品自1981年从第二汽车 When it comes to the effect of phosphorus on the thermal cracking of castings, it is generally considered that the phosphorus content is too high to form a low-melting phosphorus eutectic (Fe-Fe3P) and lower the solidus temperature. When the shrinkage of the castings is hindered, hot cracking . Therefore, phosphorus is a harmful element. So, what happens when the amount of phosphorus is too low? In fact, when the amount of phosphorus is too low, the casting will also have a thermal crack. The main bearing cover produced by our factory is for Dongfeng EQ 140 car loading, the material is HT 20-40, the size is shown in Figure 1, the process diagram is shown in Figure 2. The product since 1981 from the second car