When the heat-resistant steel castings work in atmospheric conditions, due to the influence of various external factors, the surface may have different degrees of corrosion. What would happen if heat-resistant steel castings were used in vacuum?

The heat-resistant steel castings are under the conditions of high temperature, low pressure and low oxygen content. Although corrosion may occur, this kind of corrosion is different from that under atmospheric conditions, resulting in the failure of heat-resistant steel castings. The results show that the damage process of heat-resistant steel castings is dominated by oxidation and volatilization under high temperature and vacuum.

In other words, oxidation dominates the failure process of heat-resistant steel castings in low vacuum, while volatilization dominates the failure process of heat-resistant steel castings in high vacuum. Therefore, the volatilization of alloy components in heat-resistant steel castings is very small under low vacuum.

However, at this time, the heat-resistant steel casting is in the low oxygen partial pressure medium, and the micro oxygen enters into the heat-resistant steel alloy through the oxide film, which causes the oxidation film to thicken, the effective cross-section decreases, and the resistance increases, which will also cause the casting failure.

It is only said that this process will be much slower than that in air, especially, it is very necessary to select suitable heat-resistant steel alloy, which can at least reduce the occurrence of failure, improve the utilization rate of heat-resistant steel castings and give full play to its value.