Hot forming processing simulation of torsion beam of high strength steel 22MnB5

To study the forming process of V-shape torsion beam using high strength steel tube 22MnB5 under the method of gas forming at elevated temperature, numerical simulation was carried out to analyze the temperature field, stress field, strain field, thickness distribution and form precision. Material flow stresses in different areas change because of difference of temperature distribution, so the max principal stress is located on the low temperature area and the max principal strain is located on the high temperature and high expansion rate area. With the raising of initial tube temperature, the lowest temperature and biggest thinning rate of formed torsion beam increase and the forming precision improves simultaneously. And with the raising of coefficient of friction, the biggest thinning rate of formed torsion beam increases. When the initial temperature is 850℃, the coefficient of friction is 0.1, and the calibration pressure is 20 MPa, the reasonable pieces with high precision and low thinning rate of 14% can be obtained, and at the same time the lowest temperature is 499℃ which is far higher than the beginning of martensitic transformation.