The tempering temperature of high chromium cast iron

Plastic Infusion Apparatus Parts Manufacturers

They will not change in the subsequent heat treatment process. Inspection and use results After the heat treatment of the high chromium roll, the high chromium cast iron on the roll surface and the gray cast iron of the roll core were inspected. The high chromium rolls developed by our factory have reached the current level of similar foreign rolls, and some quality indicators have reached the current international level, setting a precedent for the successful use of high chromium rolls on old hot strip mills.. The higher the tempering temperature, the greater the effect of reducing the retained austenite and residual stress, but the excessively high tempering temperature will significantly reduce the hardness, which is obviously not what we want.

The choice of fire temperature The tempering temperature of high chromium cast iron can be seen from the table according to different situations. The sample can get the desired structure under the air-cooling condition, but the half-cooling time is the hardness of the required roll surface, which is equivalent to one. The half-cooling time is a significant increase in the hardness of the sample. The morphology and distribution of the eutectic carbides of the high chromium roller and the matrix structure of the eutectic carbides are mainly determined by the solidification rate of the alloy composition and the gravity coefficient for centrifugal casting.  According to past experience,

due to the residual stress of the composite roll, its hardness is higher than the hardness of the sample cut from the roll body, so it can be determined that the matrix and hardness value obtained at this cooling rate meet the requirements.The choice of cooling rate In order to verify whether the selected high chromium cast iron can Plastic Infusion Apparatus Parts Manufacturers obtain the required matrix structure and hardness under air cooling conditions, the samples are cooled to the inside for controlled cooling according to the half-cooling time, and part of the samples are tempered ,

The results are listed in the table and vary widely. During centrifugal casting, the eutectic carbides formed in high chromium cast iron are very uniform due to the large cooling rate and coefficient of gravity, which are in the pattern of typical eutectic carbides of high chromium cast iron. The hardness of the samples tempered at medium temperature is higher, so this tempering temperature is selected. The test results are compared with the data of high grid rolls from some foreign manufacturers

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