Calculation and comparison between alternate and continuous controlled cooling technology for X65 pipeline steel plate
1.Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650093,China; 2.Faculty of Applied Technology, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; 3.Office of Vocational Skills, Kunming Metallurgy College, Kunming, Yunnan 650033, China
Abstract：To decrease the residual stress and warping of X65 pipeline steel plate after controlled cooling, a thermo-mechanical coupled FEM model was established according to linear mixture thermal expansion model, modified Avrami transformation dynamics model and Leblond transformation induced plasticity (TRIP) model. All relevant physical effects of elastoplastic deformation, thermal expansion, latent heat, transformation dilatation and TRIP effect were considered in the FEM model. Temperature, residual stress, residual strain and warping of X65 pipeline steel plate were analyzed by the proposed model under two controlled cooling technologies. The results show that the temperature of plate under alternate controlled cooling is 7 ℃ less than that under continuous controlled cooling. The residual tensile stress peak value near top surface is decreased by 44 MPa with enhanced residual compressive strain peak value of 0.001 near bottom surface, while the warping is reduced from 0.54×10-3 to 0.09×10-3. Alternate controlled cooling can reduce residual stress and warping of plate.
2012, Vol. 33 
