In this research the effect of initial microstructure on hot deformation behavior in terms of Ferrite-to-Austenite ratios is studied. Two types of stainless steels C1 and C2 were homogenizing heat-treated and deformed under hot compression examinations at temperatures 900ºC and 1100ºC at strain rate of 0.1s-1. The results showed that the flow stress levels of specimens are strongly r...

The hot compression tests were carried on X45CrNiW189 valve steel (X45) in the temperature range of 1000– 1200 °C and the strain rate range of 0.004 – 0.5 s-1 in order to study the high temperature softening behavior of this steel. For the exact prediction of flow stress, the effective stress-effective strain curves were obtained from experiments under various conditions. On the basis of experi...

Many efforts have been made to model the the hot deformation (dynamic recrystallization) flow curves of different materials. Phenomenological constitutive models, physical-based constitutive models and artificial neural network (ANN) models are the main methods used for this purpose. However, there is no report on the modeling of warm deformation (dynamic spheroidization) flow curves of any kin...

In industrial metal-forming processes, quantitative and physical models are required to control and optimize the microstructure of the finished products. A detailed understanding of the behavior of polycrystalline materials during deformation processes is essential to develop such models. A number of instruments and analytical tools are available for deformation studies within the microscopy an...

A hot tear indicator based on the physics of solidification and deformation is presented. This indicator is derived using available data from computer simulation of solidification and solid deformation. Hot tears form when the mushy zone is starved of liquid feeding and deformed in tension. The unfed tensile deformation causes a small additional porosity. A physical model based on a mass balanc...

in the present study, the microstructural changes of a nickel based superalloy nimonic80a during a non-isothermal deformation were studied. therefore, microstructure evolutionduring hot side pressing test was predicted with combined methods of finite element analysis andprocessing map of the material. the predicted results were validated through experimentalmicrostructural studies. the results ...

experiments were carried out in which the dependence of the fractional softening on temperature, time and strain rate was determined in a 304h stainless steel. three prestrain ranges were identified pertaining to three different post-deformation softening behaviors: 1) prestraining to below the drx critical strain: strongly strain dependent softening by srx alone with softening kinetics control...

effect of small al additions, from 0.14% to 0.31% ai, on the hot deformation behavior of low carbon steels containing 1%cu-1.2%mn was investigated in the temperature range of 750-800•c over the strain rate range of 1o.3.1o.1s•1 by a hot compression testing machine. the flow curves obtained, exhibited typical characteristics of dynamic recovery type of softening mechanism, and the critical strai...