High Temperature Mechanical Properties and Calculation of Critical Strain for 42CrMo Ring Blank Based on Casting-rolling Forming

doi:10.3901/JME.2017.06.045

Abstract

Abstract:

Ring blanks removed from the mold under high temperature are easy to emerge crack defect in casting-rolling continuous forming process. According to this, high temperature tensile test of as-cast 42CrMo steel is carried out in a Gleeble-3500 thermal-mechanical simulator. Mechanical behaviors of the steel such as high temperature strength, thermoplastic, etc, are analyzed. The cracking sensitive to temperature zone is predicted. It is shown from the results that the tensile strength decreases with the increase of temperature and the decrease of strain rate, and reduction of area increases with the increase of strain rate. Dynamic recrystallization occur at the temperature of 1 100 ℃. There are two brittleness zones under the experimental conditions, which are red brittleness temperature zone and high temperature brittleness temperature zone respectively. High temperature brittleness is the intrinsic cause that leads to crack for as-cast 42CrMo high temperature ring blank. The energy spectrum analysis indicates that the cracks are easily induced by sulfide and oxide and other inclusions. Based on the experimental results, the peak flow stress model and the critical strain model of the crack are established for as-cast 42CrMo steel. The proposed models are helpful to optimize casting-rolling continuous forming process, avoid casting defects and improve the quality of the castings.

Key words: critical strain, dynamic recrystallization, high temperature mechanical property, metallic material

WU Yonghong, LI Yongtang, QI Huiping, FU Jianhua. High Temperature Mechanical Properties and Calculation of Critical Strain for 42CrMo Ring Blank Based on Casting-rolling Forming[J]. Journal of Mechanical Engineering, 2017, 53(6): 45-52.

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