The Effect of Heat Treatment on the Quality Characteristics of Metal Materials

This study collects data on four physical properties of four different products of the case company after heat treatment: hardness, length, inner diameter, and outer diameter. 25 samples were collected for each product, and the statistical method t-test was used to test whether the four physical properties were significantly different before and after heat treatment. There are significant differences in the four physical properties of four different products before and after heat treatment by T-test. The results are as follows: (1) Hardness: S45C: After heat treatment, the difference in physical durability becomes larger, and the hardness has a significant difference. (2) Length: S45C: After heat treatment, its length becomes significantly longer. (3) Inner diameter: S45C: After heat treatment of medium carbon steel, the size after treatment is smaller than that before treatment, and there is a significant difference. (4) Outer diameter: S45C: After heat treatment, the “outer diameter” is significantly larger than before treatment, and generally must be reserved for processing.