Study on Stress Concentration and Normal Magnetic Memory Signal Gradient of Q235 Steel

The metal magnetic memory testing technique was used to detect the magnetic properties of Q235 steel specimens under uniaxial tensile load. In this work, a new gradient Kxy was proposed, which is normal component of magnetic memory signal in the two directions where length and width of the specimen. The results show that it has a good correspondence with the stress concentration area in the elastic stage, the location of the stress concentration of the tested specimen can be determined by Kxy, it solves one problem that the position of the stress concentration is not accurate by zero crossing point of the normal component of magnetic memory signal curve of a single track line on the surface of the specimen.