The Performance Research Of A3 Steel Pre-torsion Deformation

The A3 steel which is typical plastic material is widely employed in the engineering structure. In order to save the steel products and reduce the cost, people usually use the cold-work hardening to strengthen the metal , and the tension strengthen has the widespread project application. But the research of A3 steel mechanics performance under the pre-torsion deformation is not many, especially the experimental standard of constant amplitude torsion fatigue is not exist temporarily. In this paper, the mechanics performance of the A3 steel material which after the pre-torsion deformation is researched and analyzed, and the changing mechanism of mechanics properties has carried on the exhaustive elaboration from the microscopic aspect.The tension and compression mechanics performance of the A3 steel specimen which after the pre- torsion deformation is studied in this paper. The Baushinger's effect of the A3 steel which existed in the torsion process is researched . the results indicated that, the Baushinger's effect of the A3 steel which in torsion process is similar with the tension process, when the material pre-torsion deformation is not big, it can be used kinematic hardening model to describe the material constitutive relationship, when the material pre-torsion deformation is big, it can be used mixture strengthen model to describe the material constitutive relationship, and the research of this aspect is not reported at presentThe specimens of A3 steel and A3 steel after quenching and tempering treatment are carried on the big strain value pulsant fatigue and the symmetrical fatigue performance research separately, and the torque-torsion angle curves of the A3 steel and the A3 steel after quenching and tempering treatment are obtained. the curves of torsion angle-circle and the torque-torsion angle of the A3 steel and A3 steel after quenching and tempering treatment specimens which under symmetrical fatigue and pulsant fatigue are obtained, this may be have the project reference.The metallographic specimens was made by the fatigue destron specimen section of the A3 steel and analyzed. Changing properties of material mechanics performance caused by microcosmic structure was analyzed. There were two main reasons that plastic deformation caused hardening of material. One was the dislocation density aggrandizement caused by plastic deformation. The other was the contribution of refinement of sub-grain structure in A3 steel.The solid circular shaft torsion of Low-carbon steel is numerical simulation by use ANSYS software which the constitutive relationship is defined by the ideal elastic-plastic and the solid circular shaft trosion experiment. And the stress at any point in the cross section of the Low-carbon steel torsion process is studied. The qualitative conclusion was that the constitutive relationship model derivated by the method of circular shaft trosion experiment was more accurate than other models.