Effect of Stretch-Bending Straightening on the Residual Stress of C19400 Alloy Strips

Stretch-bending straightening is an effective method for controlling the internal residual stress of a strip. The evolutions of dislocation and grain orientation in the process of the bending straightening of the alloy strips was discussed by means of TEM and EBSD, and the influence mechanism of stretch-bending straightening on the residual stress of strips was explored. The results show that: When the tension force is 45 MPa, in this case, the strength increases from 424.4 to 427.8 MPa; the transverse and rolling direction residual stress levels decrease from - 6 and -66 MPa to - 5 and - 7 MPa, respectively, reductions of approximately 86.1 and 74.2%. The microstructure demonstrates that the material strength is increased due to the obstruction of dislocation motion, while the residual stress level is reduced due to the initiation of dislocation slip and the transformation of the texture to a more favourable one.