High cycle fatigue property and fracture behavior of high-strength austempered ductile iron

Abstract

The high cycle fatigue tests of high-strength austempered ductile iron of grade 1200/850/04 (ASTM 897 M-06) were conducted by the high frequency fatigue machine. The results show that the S–N curve decreases continuously and there is no conventional fatigue limit at 10⁷ cycles. According to the fracture surface observations, at short fatigue life region the specimens fail from defects at specimen surface and at long fatigue life region the specimens fail from internal defects with fish-eye area around it. According to the defect sizes measured in the standard inspection areas of the material, the maximum defect size evaluated by the statistics of extreme values method is in accordance with that of the fatigue test results. Meanwhile, it is obvious that the fatigue strength of austempered ductile iron is influenced by the original defect size and the fatigue limit can be well evaluated by the Murakami equation.

Keywords

Austempered ductile iron high cycle fatigue S–N curve fracture surface defect size

Get full access to this article

View all access options for this article.

References

Lerner

Kingsbury

. Wear resistance properties of austempered ductile iron. J Mater Eng Perform 1998; 7: 48–52.

Batra

Ray

Prabhakar

. Austempering and austempered ductile iron microstructure in copper alloyed ductile iron. J Mater Eng Perform 2003; 12: 426–429.

Eric

Sidjanin

Miskovic

. Microstructure and toughness of CuNiMo austempered ductile iron. Mater Lett 2004; 58: 2707–2711.

Zhang

. Microstructure and mechanical properties of austempered ductile iron with different strength grades. Mater Lett 2014; 119: 47–50.

Chapetti

. High-cycle fatigue of austempered ductile iron (ADI). Int J Fatigue 2007; 29: 860–868.

Lefevre

Hayrynen

. Austempered materials for powertrain applications. J Mater Eng Perform 2013; 22: 1914–1922.

Aslantas

Tasgetiren

. A study of spur gear pitting formation and life prediction. Wear 2004; 257: 1167–1175.

Kuna

Springmann

Madler

. Fracture mechanics based design of a railway wheel made of austempered ductile iron. Eng Fract Mech 2005; 72: 241–253.

Stokes

Gao

Reed

PAS

. Effects of graphite nodules on crack growth behaviour of austempered ductile iron. Mater Sci Eng A Struct Mater Prop Microstruct Process 2007; 445: 374–385.

10.

Tayanc

Aztekin

Bayram

. The effect of matrix structure on the fatigue behavior of austempered ductile iron. Mater Des 2007; 28: 797–803.

11.

Zammit

Mhaede

Grech

. Influence of shot peening on the fatigue life of Cu-Ni austempered ductile iron. Mater Sci Eng A Struct Mater Prop Microstruct Process 2012; 545: 78–85.

12.

A 897M-06. Standard Speciﬁcation for austempered ductile iron castings. In: Annual Book of ASTM Standards, 2006.

13.

Murakami

. Metal fatigue: effects of small defects and non-metallic inclusions, Tokyo: Yokendo Ltd, 1993.

14.

Murakami

Toriyama

Coudert

. Instructions for a new method of inclusion rating and correlations with the fatigue limit. J Test Evaluat 1994; 22: 318–326.

15.

Murakami

Beretta

. Small defects and inhomogeneities in fatigue strength: experiments, models and statistical implications. Extremes 1999; 2: 123–147.

16.

Gumbel

. Statistics of extremes, New York: Columbia University Press, 1958.