In addition to chemical composition, the influence of other production processes mainly refers to the influence of melting process, spheroidizing treatment process and inoculation treatment process on the mechanical properties of nodular cast iron.
The effects of process parameters of A1-A5 on mechanical properties are listed in the table.
| Number | T out | T pouring | T reaction | Spheroidizing agent | Inoculant | Package bottom | Follow flow | Instantaneous | Mg residue | Re disability | Tensile strength | Impact absorption energy |
| A1 | 1536 | 1389 | 147 | 1.5 | 1.5 | 0.8 | 0.6 | 0.1 | 0.03 | 0.01 | 381 | 8.7 |
| A2 | 1495 | 1321 | 115 | 1.5 | 1.7 | 1.0 | 0.6 | 0.1 | 0.04 | 0.01 | 389 | 10.5 |
| A3 | 1472 | 1360 | 80 | 1.7 | 1.7 | 0.8 | 0.8 | 0.1 | 0.06 | 0.01 | 413 | 11.8 |
| A4 | 1468 | 1355 | 113 | 1.4 | 1.7 | 0.8 | 0.8 | 0.1 | 0.05 | 0.01 | 422 | 12.6 |
| A5 | 1510 | 1383 | 110 | 1.5 | 1.7 | 0.8 | 0.8 | 0.1 | 0.04 | 0.01 | 480 | 10.4 |
It can be seen from the table that when the discharge temperatures of A1, A2 and A5 are high, the burning loss of magnesium is large and the content of residual magnesium is low. When the discharge temperature of A3 and A4 is low, the burning loss of magnesium is small. Even if the amount of spheroidizing agent is reduced, the content of residual magnesium is also high. Because an appropriate amount of residual magnesium will ensure the spheroidizing effect and improve the mechanical properties of nodular iron. In order to control the residual magnesium content in nodular cast iron, the discharge temperature of molten iron should be controlled first. The experiment shows that the optimum temperature of molten iron is about 1470 ℃.
In the experiment, when the amount of A3 spheroidizing agent is too much, the residual magnesium content is high, and the low-temperature impact toughness of nodular cast iron will also be reduced. It can be seen that the amount of spheroidizing agent is not the more, the better. From the experimental results, the mechanical properties of nodular cast iron are better when the residual magnesium is 0.05%.
In addition, inoculation treatment process will also affect the mechanical properties of nodular cast iron. In the experiment, after reducing the inoculation amount at the bottom of the ladle and increasing the inoculation amount with the flow, the mechanical properties are improved, and the effect of inoculation with the flow is better than that at the bottom of the ladle. Therefore, in order to obtain high performance in production, the method of multiple inoculation should be adopted, and the flow inoculation should be strengthened as much as possible on the premise of ensuring the addition time.