1) The strength and elongation properties of y-block hot metal casting were compared. It can be seen that with the increase of silicon content, the strength of the casting increases and the elongation decreases, and the solid solution strengthening effect of silicon is similar to that of Y block.

2) The hardness data of different parts of the casting before, during and after the same ladle of hot metal are taken from the corresponding casting body.

It can be seen that the hardness difference of nodular cast iron puma main cover casting with silicon solution strengthening is hb19, while that of alloyed mixed matrix nodular cast iron puma main cover casting is hb40; The hardness difference of silicon solution strengthened nodular cast iron v348 differential case is hb19, while that of alloyed mixed matrix nodular cast iron v348 differential case is HB71.

The hardness process capacity CPK of Puma main cover and v348 differential case body of nodular cast iron strengthened by silicon solution are 5.17 and 2.25 respectively. The hardness distribution is shown in Fig. 1 and Fig. 2.

Compared with the original process of alloying mixed matrix nodular cast iron, it can be seen that the silicon solid solution strengthened nodular cast iron greatly improves the hardness stability and process ability of the casting, and has a good effect on improving the processability of the casting. After the trial production, the castings were well received by the manufacturers.