Effect of main inclusions on crack initiation in bearing steel in the very high cycle fatigue regime

Abstract

This work aims to investigate the effect of main inclusions on crack initiation in bearing steel in the very high cycle fatigue (VHCF) regime. The size and type of inclusions in the steel were quantitatively analyzed, and VHCF tests were performed. Some fatigue cracks were found to be initiated in the gaps between inclusions (Al₂O₃, MgO-Al₂O₃) and the matrix, while other cracks originated from the interior of inclusions (TiN, MnS). To explain the related mechanism, the tessellated stresses between inclusions and the matrix were calculated and compared with the yield stress of the matrix. Results revealed that the inclusions could be classified into two types under VHCF; of these two, only one type could be regarded as holes. Findings in this research provide a better understanding of how inclusions affect the high cycle fatigue properties of bearing steel.

Keywords

very high cycle fatigue / bearing steel / inclusions / tessellated stress / crack initiation

References

[1] Nguyen H.Q., Gallimard L., Bathias C. Numerical simulation of fish-eye fatigue crack growth in very high cycle fatigue. Eng. Fract. Mech., 2015, 135, 81.

[2] Xu L.P., Wang Q.Y., Zhou M. Micro-crack initiation and propagation in a high strength aluminum alloy during very high cycle fatigue. Mater. Sci. Eng. A, 2018, 715, 404.

[3] Hong Y.S., Lei Z.Q., Sun C.Q., Zhao A.G. Propensities of crack interior initiation and early growth for very-high-cycle fatigue of high strength steels. Int. J. Fatigue, 2014, 58, 144.

[4] Gao G.H., Zhang B.X., Cheng C., Zhao P., Zhang H., Bai B.Z. Very high cycle fatigue behaviors of bainite/martensite multiphase steel treated by quenching-partitioning-tempering process. Int. J. Fatigue, 2016, 92, 203.

[5] Wang Q.Y., Berard J.Y., Rathery S., Bathias C. Technical note high-cycle fatigue crack initiation and propagation behaviour of high-strength sprin steel wires. Fatigue Fract. Eng. Mater. Struct., 1999, 22(8): 673.

[6] Murakami Y., Nomoto T., Ueda T., Murakami Y. On the mechanism of fatigue failure in the superlong life regime (N>107 cycles). Part 1: influence of hydrogen trapped by inclusions. Fatigue Fract. Eng. Mater. Struct., 2000, 23(11): 893.

[7] Murakami Y., Nomoto T., Ueda T., Murakami Y. On the mechanism of fatigue failure in the superlong life regime (N >107 cycles). Part II: a fractographic investigation. Fatigue Fract. Eng. Mater. Struct., 2000, 23(11): 903.

[8] Murakami Y., Nomoto T., Ueda T. Factors influencing the mechanism of superlong fatigue failure in steels. Fatigue Fract. Eng. Mater. Struct., 1999, 22(7): 581.

[9] Shiozawa K., Morii Y., Nishino S., Lu L. Subsurface crack initiation and propagation mechanism in high-strength steel in a very high cycle fatigue regime. Int. J. Fatigue, 2006, 28(11): 1521.

[10] Shiozawa K., Lu L., Ishihara S. S-N curve characteristics and subsurface crack initiation behaviour in ultra-long life fatigue of a high carbon-chromium bearing steel. Fatigue Fract. Eng. Mater. Struct., 2001, 24(12): 781.

[11] Sakai T., Sato Y., Oguma N. Characteristic S-N^properties of high-carbon-chromiumbearing steel under axial loading in long-life fatigue. Fatigue Fract. Eng. Mater. Struct., 2002, 25(8-9): 765.

[12] Murakami Y., Endo M. Effects of defects, inclusions and inhomogeneities on fatigue strength. Int. J. Fatigue, 1994, 16(3): 163.

[13] Murakami Y., Kodama S., Konuma S. Quantitative evaluation of effects of nonmetallic inclusions on fatigue strength of high strength steel. Trans. Jpn. Soc. Mech. Eng. A, 1988, 500(54): 688.

[14] Murakami Y., Usuki H. Prediction of fatigue strength of high-strength steels based on statistical evaluation of inclusion size. Trans. Jpn. Soc. Mech. Eng. A, 1989, 510(55): 213.

[15] Sun C., Xie J., Zhao A., Lei Z., Hong Y. A cumulative damage model for fatigue life estimation of high-strength steels in high-cycle and very-high-cycle fatigue regimes. Fatigue Fract. Eng. Mater. Struct., 2012, 35(7): 638.

[16] Li W., Sakai T., Deng H. Statistical evaluation of very high cycle fatigue property of high carbon chromium bearing steel under axial loading. Mater. Sci. Technol., 2016, 32(11): 1094.

[17] Spriestersbach D., Grad P., Kerscher E. Influence of different non-metallic inclusion types on the crack initiation in high-strength steels in the VHCF^regime. Int. J. Fatigue, 2014, 64, 114.

[18] Karr U., Schuller R., Fitzka M., Schönbauer B., Tran D., Pennings B., Mayer H. Influence of inclusion type on the very high cycle fatigue properties of 18Ni maraging steel. J. Mater. Sci., 2017, 52(10): 5954.

[19] Deng Z.Y., Zhu M.Y. Evolution mechanism of non-metallic inclusions in Al-killed alloyed steel during secondary refining process. ISIJ Int., 2013, 53(3): 450.

[20] Itoh H., Hino M., Banya S. Thermodynamics on the formation of non-metallic inclusion of spinel (MgO·Al₂O₃) in liquid steel. Tetsu-to-Hagane, 1998, 84(2): 85.

[21] Gu C., Bao Y.P., Lin L. Cleanliness distribution of high-carbon chromium bearing steel billets and growth behavior of inclusions during solidification. Rev. Metal., 2017, 53(1): 1.

[22] Brooksbank D., Andrews K.W. Tessellated stresses associated with some inclusions in steel. J. Iron Steel Inst., 1969, 207(4): 474.

[23] Ma Y., Pan T., Jiang B., Su Y.H. H., Peng Y. Study of the effect of sulfur contents on fracture toughness of railway wheel steels for high speed train. Acta Metall. Sin., 2011, 47(8): 978.

[24] Brooksbank D., Andrews K.W. Thermal expansion of some inclusions found in steels and relation to tessellated stresses. J. Iron Steel Inst., 1969, 206(6): 595.

[25] Wang Y.N., Bao Y.P., Wang M. Nanoindentation characterization of non-metallic inclusions in free cutting steel. J. Univ. Sci. Technol. Beijing, 2014, 36(7): 903.