Q345B低温变形抗力模型及在矫直工艺中的应用

通过Gleeble-1500热模拟试验机对低合金钢Q345Bφ10mm×30mm圆件体试样在450～650℃以0.001～0.1s^-1变形速率进行真应变为0.15拉伸试验。结果表明,低温低变形速率状态下的变形抗力处于弹塑性变形区,线性段较长,当变形量大于0.06以后出现较明显塑性变形,变形抗力的变化规律与较高温状态基本类似。通过采集实验数据,应用Origin软件通过多元非线性回归建立了Q345B钢变形抗力的数学模型。应用该模型结合矫直理论公式计算了中厚板9辊矫直机矫直力,计算结果的相对误差为0.01%～6.71%。

Math Model for Deformation Resistance of Steel Q345B at Low Temperature and Its Application in Straightening Process

The hot tensile test ofΦ10 mm×30 mm cylinder specimen of low alloy steel Q345B with true strain 0.15 and strain rate 0.001 ⁰.1 s^-1 at 450～650℃has been carried out by Gleeble-1500 thermal test machine.Results showthat with low strain rate at lower temperature the deformation resistance is at elastic-plastic deformation stage and its linear section is longer,and as deformation is larger than 0.06,the apparent plastic deformation of steel occurs and the change rule of deformation resistance is basically similar to that at higher temperature.Based on test data the math model for deformation resistance of steel Q345B is established by using Origin software with multivariate nonlinear regression.The straightening force of 9 rolls straightener for medium and heavy plate is calculated by using this model combined with straightening theoretical equation,the relative error of calculated results are 0.01%⁶.17%.