The Influential Factors of Baking Time in Internal Friction and Bake-Hardening Properties on Low Carbon Steel

This paper aims at exploring the distinctive ways of baking time affecting the hardening degree of the cold-rolled steel. Therefore, with different time span, the annealed sample was baked to test its baking hardening properties. The sample was analyzed micro-structurally after being annealed, pre-deformed and baked. The internal friction was simultaneously measured in terms of different processing conditions during experiments. The following findings are the significant conclusion of the experiments: The important experiment result indicated that when the degree of pre-deformation setting at 5% and the baking temperature at 170°C, the BH value increased but remained unchanged afterwards. Furthermore, when the baking time span was set at 1000 minutes, the BH value reached the maximum but would remain unchanged afterwards. When the degree of pre-deformation was set at 5%, and the baking temperature was set at 17°C with baking time 20 minutes, the SKK peak reached the maximum. When the baking time was 1000 minutes and constantly extended, the height of SKK peak rarely changed. The above experiments are designed to better illustrate and understand the significance of the hardening steel properties for future application in the automobile industry.