Determination of the critical damage for 100Cr6 steel under hot forming conditions

Abstract

In this study, the critical values of damage were determined for 100Cr6 grade steel specimens subjected to forming in the temperature range of 950–1150 °C. This was done using 8 phenomenological criteria of failure and 3 calibration tests based on uniaxial tension, torsion and rotary compression. Experiments were performed on test stands installed at the Czestochowa University of Technology and the Lublin University of Technology. The above calibration tests were modelled numerically using the commercial simulation software Simufact. Forming v. 15. The average values of temperature, strain rate and critical damage were calculated for every calibration test. Results showed a significant relationship between critical damage and forming temperature. A comparison was made between the critical damage values obtained in the torsion and tensile tests, performed at similar temperatures and strain rates. It has been found that the relationship between the critical damage values determined via torsion and uniaxial tensile testing is fairly stable for the dimensionless fracture criteria, i.e. those formulated by Oh, Oyane and Brozzo.