Simulation of Heat Treatment Response and Distortion of Bearing Steels

Abstract

The present paper is a review of recent results on simulation of heat treatment response of bearing steels. Two aspects are considered namely firstly the evolution of the microstructure during heat treatment, especially the carbide structure and the corresponding distribution of alloying elements in the austenite around the carbides. This information is important in order to understand the hardening response of the steel. The analysis is based on thermodynamics and kinetics of multi component systems. Both single carbide sizes and realistic size distributions are considered. Secondly the evolution of the residual stresses and the distortion is considered during the full heat treatment cycle including heating and cooling. These latter simulations focus on the behaviour of full components. Special interest is devoted to origins of out of roundness of bearing rings. Factors like original geometrical imperfections, residual stresses from mechanical manufacturing steps, segregation and uneven cooling action during quenching are considered.

FEM modeling and experimental validation of quench-induced distortions of large size steel forgings

“…The latter can only be precisely achieved with a comprehensive understanding of the conjugate consideration of thermal, mechanical, and metallurgical interactions and their relative sequences during the quench process. For example, in the presence of a large range of cooling rates [8] (due to part size, shape, quench intensity, hardenability, etc.) different scenarios of phase transformation are expected in the same component (i.e., time history of phase transformations).Therefore, quantifying phase transformation during the quench process is of critical importance because of its impact on distortion characteristics.…”

“…different scenarios of phase transformation are expected in the same component (i.e., time history of phase transformations).Therefore, quantifying phase transformation during the quench process is of critical importance because of its impact on distortion characteristics. The strain state during hardening is directly correlated with distortion, and is mainly driven by the thermal expansion and the volume change of the newly formed microstructures as a result of phase transformation [8]. The strain state is also affected by the transformation-induced plasticity (TRIP) phenomenon, which causes a permanent deformation of the soft austenite phase (parent phase) [9].…”

Manufacturing Residual Stress States in Heat Treatment Simulation of Bearing Rings

“…According to the temperature dependence of the thermal strain (Fig. 3) the maximum amounts of these compressive and tensile stresses were reached at a temperature of 10 C. During decreasing of the thermal strain (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) C) a rearrangement of the stresses can be observed which resulted in a residual stress distribution with tensile stress at the surface and compressive stress in a certain distance from the surface. At a distance of 0.25 mm the residual stresses were of negligible magnitude.…”

“…He investigated the influence of stress relieving on the distortion of rings (SAE 52100): In a first simulation a ring was deformed axially on a small segment, which generated a stress pattern. This stress pattern produced a significant out of roundness distortion during the subsequent stress relieving heat treatment [12]. In another paper the relieving of internal stresses in experiments and simulations, including three point bending of a tube to insert residual stresses, ring turning with cut off from the tube, and a soft annealing heat treatment for stress relieving was investigated.…”

Influence of clamping conditions on distortion during heating of bearing rings

“…Thuvander succeeded in overcoming these problems by using the commercial finite element code ABAQUS in combination with DistSIMR. He investigated the influence of stress relieving on the distortion of rings (SAE 52100) [4,11].…”