Theoretical Calculation And FEM Simulation Analysis In Steel Tube Reducing Process

As the finishing step in hot rolling of seamless steel tube, reducing technology decides the end product rate and quality. It is the development trend of steel tube reducing technology to go through from empirical analysis to quantitative analysis as every modern science and technology.There is obvious metal flow in tube reducing. Based on the calculation of rolling pressure after study on strain and stress distribution, it can help to make proper choice of rolling mills, profile and strength of rollers; dimensional relationship between raw tube and its end product can be determined by analysis on the law of metal flow in reducing deformation, so it's worth of studying for working out a reasonable tube reducing technology.Rolling process of raw tubes reduced by 12 slight stretch reducing mills from 219*6.55 to 194*6.8 were analyzed with classical rolling deformation theory and plastic-elastic FEM. Thus, the wall thickness and rolling pressure of each mill were calculated by engineering method, 3D metal flow is visually simulated by ANSYS/LS-DYNA; the result of engineering calculation is verified by experiment data to establish model.The experimental data of wall thickness at both ends were approximate to the theoretical values and FEM analysis. As wall thickness has effect on the product rate, engineering calculation is practical to wall thickness control at both ends and arrangement of rolling line; strain and stress distribution, rolling pressure and thickness changing law obtained by FEM matches well with reality and can give good explanation to phenomenon of non-uniform wall thickness, therefore it's effective to use 3D plastic-elastic FEM in analysis of tube reducing process. Practical wall thickness model has been established by regression on major effect factors, and it plays an important and practical role in actual production process.Further study of reducing process with combination of 3 methods above is helpful in determination of the best processing technology as well as shortening new products developing circle, and it is also significant in enhancement of production, quality and product rate.