厚向强度分布对特厚板三辊预弯成形的影响

Influence of material strength distribution along thickness on three-roller edge pre-bending of thick plate

选取100、220mm两种厚度Q235热轧板，在厚向多个等间距分布位置切取圆棒试样，采用WAW-E100试验机获得各试样在3．0×10%^-5S^-1应变速率时的拉伸应力应变曲线。根据拉伸试验数据建立考虑厚向强度分布的材料应力-应变函数。分析特厚板在CDWllXNC-300＼420mm〈2500mm重型三辊卷板机上的预弯成形过程并建立预弯工艺模型。预弯模型计算结果表明，特厚板厚向强度变幅为0～20％时，上辊垂直力增幅约为0～13％，回弹比略有增加，卸载前预弯角无明显变化。

Three-roller edge pre-bending of thick plate is affected by non-uniform material strength distribution along the thickness introduced by multi-pass roll forming and heat treatment. Hot-rolled Q235 plates with thickness of 100 mm and 200 mm were investigated by tensile testing of round bars from equal spaced multi-positions along the thickness. The material stress-strain curves of tensile bars were achieved by tensile testing on WAW-E100 machine at a strain rate of 3. 0 ×4 10 ^-5 s^- 1. The stress-strain relationship of the material considering the non-uniform distribution was obtained. Three-roller edge pre-bending process of thick plate on CCDWllXNC-300／420 × 2500 mm heavy machine with bottom rollers horizontally adjustable was analyzed and an edge pre-bending model was developed. Numerical results by this model show that a strength variation of 0～20 % along thickness could result in top-roller force variation of 0～13%, on pre-bending angle before unloading. little increase in springback ratio, and no effect