Life prediction of l6 steel using strain-life curve and cyclic stress-strain curve by means of low cycle fatigue testing

7th International Conference on Key Engineering Materials

材料科学;工业技术

Inamdar, Sanket^1 ; Ukhande, Manoj^2 ; Date, Prashant^3 ; Lomate, Dattaprasad^1 ; Takale, Shyam^2 ; Singh, R.K.P.^1

Kalyani Centre for Technology and Innovation, Bharat Forge Ltd., Pune

411036, India^1

R and D CDFD Engineering, Bharat Forge Ltd., Pune

411036, India^2

Indian Institute of Technology Powai, Mumbai

400076, India^3

关键词: Closed-die hot forging;    Cyclic stress strain curves;    Cyclic stress-strain behavior;    Fatigue test machine;    Low cycle fatigue testing;    Low-cycle fatigue tests;    Metal-forming process;    Strain life curve;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/201/1/012037/pdf
DOI  :  10.1088/1757-899X/201/1/012037

来源: IOP

【 摘 要 】

L6 Steel is used as die material in closed die hot forging process. This material is having some unique properties. These properties are due to its composition. Strain softening is the noticeable property of this material. Due to this in spite of cracking at high stress this material gets plastically deformed and encounters loss in time as well as money. Studies of these properties are necessary to nurture this material at fullest extent. In this paper, numerous experiments have been carried on L6 material to evaluate cyclic Stress - strain behavior as swell as strain-life behavior of the material. Low cycle fatigue test is carried out on MTS fatigue test machine at fully reverse loading condition R=-1. Also strain softening effect on forging metal forming process is explained in detail. The failed samples during low cycle fatigue test further investigated metallurgically on scanning electron microscopy. Based on this study, life estimation of hot forging die is carried out and it's correlation with actual shop floor data is found out. This work also concludes about effect of pre-treatments like nitro-carburizing and surface coating on L6 steel material, to enhance its fatigue life to certain extent.