一、前言冷轧低炭薄钢极成品常用来冲制汽车、拖拉机、仪表面板及日用品构件等.特别是其中的许多形状复杂的难冲件,都要求这种薄板钢在单轴拉伸时,无明显屈服点和屈服延伸现象.因为存在这种现象时,严重者会使冲压件拉裂、起皱,轻者也会由于拉伸滑移 First, the introduction Cold-rolled low-carbon steel very finished products commonly used to punching cars, tractors, instrument panels and daily necessities, etc. In particular, many of them are difficult to form complex pieces of red, require such sheet steel in the uniaxial stretching , No obvious yield point and the phenomenon of yield extension.Because of this phenomenon, severe cases will make the stamping parts of the crack, wrinkling, the light due to the slippage