The LAB research of friction and formability of if galvanized steel sheets

摘要

The research of friction characteristics of two kinds of galvanized steel sheet (a: hot dip galvanized + electrogalvanized b; EG sheet of IF steel) and the base sheet of EG was done by the multi-function friction test device of sheet forming. The different forming conditions (lubrication, temperature, and the speed of punch) were conisdered. More attention was paid to study the effect of temperature to the friction characteristics. In addition, the fundamentla formability of electrogalvanized sheet and lab analysis of the strain distribution of EG sheet under stretching process were studied. It was tried to do some farther study of the relationship betwene the friction characteristics and the strain distribution, in order to get the simple indicator of formability of sheet by the multi-function friction test device. The initial result is as followed: (1) In the same forming process condition, the increment of friction coefficient for hot dip galvanized + electro-galvanized is less than that of electrogalvanized when temperature rised. (2) The strain distribution and maximum punch stroke of deformed sheet are applicable to evaluate the formability of sheet. (3) The base sheet of EG is less sensitive to temperature and punch speed. (4) Choosing the optimum lubrication can reduce the increment of friction coefficient of EG sheet when temperature rises.