Effect of Al and Ni on Hot Deformation Behavior of 1Cr9Al(1∼3)Ni(1∼7)WVNbB Steel

The addition of Al and Ni to ferritic heat resistant steel can improve its high temperature strength and high temperature oxidation resistance. Al and Ni in steel have some effects on the thermal deformation behavior of steel. But there is less research on it. In this work, a new type of 1Cr9Al(1 similar to 3)Ni(1 similar to 7)WVNbB high aluminum ferrite heat-resistant steel was prepared by adding Al element to T92 steel and adjusting Ni content properly. Gleeble-3800 thermal simulation test machine was used to conduct isothermal and constant speed thermal compression experiment with 60% deformation at 950 similar to 1150 degrees C and 0.1 similar to 10 s(-1) strain rates, respectively. The effects of Al and Ni additions on the hot deformation behavior, peak stress and activation energy of hot deformation of the steel were studied. The rheological stress expression containing Zener-Hollomon parameters were obtained by fitting, and the constitutive equation of the test steel was established. The results show that the addition of Al and the increase of Al content significantly reduces rheological stress and peak stress under thermal compression, which greatly reduces the difficulty of test steel processing. Compared with T92 steel, the thermal deformation activation energies of four sample groups increase by 38.136%, 19.188%, 28.003%, and 11.915%, respectively. The peak stress calculated by the constitutive equation is in good agreement with the experimental data. The results show that the constitutive equation has high accuracy. The relationship between peak flow stress, deformation temperature and strain rate can be expressed well.