Stress Corrosion Behavior of Car Body Steel for Rail Wagons

Taking Q450NQR1 and S500AW car body steels as research objects, the stress corrosion cracking susceptibility of two car body steels was studied through four-point bending, U-shaped bending, slow strain rate tensile loading methods combined with electrochemical tests. The results showed that the open circuit potential of the two four-point bending specimens was the highest after being loaded with 50% yield strength stress.When the load increased, the potential gradually shifted negatively. After U-shaped bending test, no cracks were found in the bend of the two samples, and with the extension of the corrosion time, the open circuit potential shifted negatively and gradually stabilized. After the slow strain rate test, the post-yield plastic deformation area and elastic deformation area of the S500AW specimen were higher than those of the Q450NQR1 specimen, and its mechanical properties were relatively good.