Calculation of Stresses in A 970 mm Diameter Forging, Comparison with Measurements

Abstract

Elsevier Science Publishers B. v., to be published For a cylinder of a 26 NiCrMoV 115 steel, forged to 970 mm diameter and a length of 3000 mm, residual stresses were measured. For this material an isothermal transformation diagram, physical and mechanical data were available. With these data the stresses and displacements were calculated by finite element analysis using the program Thepla for oil quenching from 1100°C and for air cooling from 900°C. The calculated values for the residual stresses at the surface are in good agreement with the measurements of the stresses in longitudinal and transverse direction.(AM 0284) Globularization of pearlite enhanced by thermomechanical processingA plain high-carbon steel (0.74% C) was used to study the globularization of pearlite and the resulting change of mechanical properties. After the variation of the deformation temperature it was found that only the deformation applied after the completion of the pearlite transformation leads to the spheroidization of pearlite. The reaction time of this process was shortened to 1;10000 compared with an annealing without deformation. The kinetics of pearlite spheroidization are dependent on the pearlite lamellar thickness as well as pearlite orientation with respect to the direction of deformation. The final microstructure is considerably finer and shows a higher toughness without a significant loss of strength.(AM 0287)