Thermal Fatigue Analysis of Hot Forging Closed Dies

Abstract

The aim of this work is to develop a numerical subroutine for the commercial finite element method software QFORM VX 8.1.4 capable of predicting, simultaneously, regions of closed dies which are prone to thermal fatigue as well as the number of cycles required for thermal fatigue cracking. The numerical subroutine was based on Manson (thermal fatigue) and Coffin-Manson (number of cycles) equations. Hot forging of AISI 1045 grinding balls using AISI H13 closed dies was performed and the numerical and experimental results were compared. The findings indicated that after forging 66 grinding balls, the numerical model achieved steady state for the temperature inside the die. After forging 600 grinding balls, both the experimental and numerical results showed that the regions of the dies subjected to the highest thermal gradient were prone to thermal fatigue. In addition to that, the numerically predicted values for the onset of thermal cracking were consistent with the experimental results: 517 and 600 cycles, respectively.

A Systematic Review of Factors Affecting the Process Parameters and Various Measurement Techniques in Forging Processes

“…3D scanning technique, acoustic emissions, force waveforms, novel fasteners, measuring arm with laser scanner, expert system, and QFORM software are used for measuring quality of forging tools. [157][158][159]162] The robotized system, infrared spectrum, and laser measurement are used for monitoring forging parameters. [172,173,175] Optical sensors and 3D scanning techniques are used for monitoring quality of forgings.…”

“…Vianello et al [ 162 ] designed a subroutine for QFORM software that had the ability to predict areas of dies that are prone to thermal fatigue and number of cycles after which thermal fatigue might occur. For validation, AISI 1045 grinding balls were forged using AISI H13 dies and after 600 balls, experimental and simulation results matched to show that areas of die with thermal gradient might be thermal fatigue prone areas.…”

A New General Fatigue Limit Diagram and Its Application of Predicting Die Fatigue Life during Cold Forging

“…To the contrary, the high-cycle fatigue (HCF) life of die parts is of great importance in cold forging [ 2 ], especially during automatic multi-stage cold forging. Die fatigue life is becoming a major issue because complicated die structural analysis has become increasingly possible owing to recent advances in metal forming simulation technologies [ 3 , 4 , 5 ].…”