| Internal friction is an extremely and efficient method to supervise and test steel and other metal materials.The coming out of bake-hardening (BH) steels is a mark of that the production of metallic structural materials development has entered the stage of control of the crystal atoms, Then bake hardening effect of BH Steel What are the factors and its aging behavior are to be studied.It is found, by the measurements of the internal friction of the wire cutting sample and machines cuting sample in a temperature range from room temperature to350℃of the ultra carbon bake hardening (BH) automotive steel sheet,which were all produced by the Masteel Corp. The mechanical spectrum of the machines cuting sample presents double peaks including Snoek peak, Snoek-Ke-Ko|’’ster (SKK) peak, while the wire cutting sample exhibits three small peaks including Snoek peak, B peak and Snoek-Ke-Koster (SKK) peak, internal friction spectrums are obviously different, The aging stability of the machines cuting samples obviously not as good as wire cutting. Furthermore, The internal friction spectra Which were deformed with1%,2%,7%and then were treated at170℃for various time respeetively from room temperature to350℃have been studied too. It was found that the three kinds of deformation samples were in the baking process the Q-1br deseends until it exhibits stable value, the Snoek peak deseends or even disappears,and the SKK peak gradually increased to a stable value,the steel has the bake hardening. |
PDF Full Text Request