Influence Of Large Non-Metallic Inclusions On Bending Fatigue Strength Hardened And Tempered Steels


The article discusses the effect of large oxide impurities (a diameter larger than 10 μm in size) on the fatigue resistance of structural steel of high purity during rotary bending. The study was performed on 7 heats produced in an industrial plant. The heats were produced in 140 ton electric furnaces. All heats were desulfurized.

The experimental material consisted of semi-finished products of high-grade, carbon structural steel with: manganese, chromium, nickel, molybdenum and boron. Steel sections with a diameter of 18 mm were hardened from austenitizing by 30 minutes in temperature 880°C and tempered at a temperature of 200, 300, 400, 500 and 600°C for 120 minutes and air-cooled. The experimental variants were compared in view of the heat treatment options. Fatigue tests were performed with the use of a rotary bending machine at a frequency of 6000 cpm. The results were statistical processed and presented in graphic form.

This paper discusses the results of the relative volume of large impurities, the fatigue strength for various heat processing options.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • 1. Roiko A., Hänninen H., Vuorikari H.: Anisotropic distribution of non-metallic inclusions in a forged steel roll and its influence on fatigue limit, International Journal of Fatigue 41 (2012) 158-167.

  • 2. Kocańda S.: Zmęczeniowe pękanie metali (Metal fatigue cracking). WNT Warszawa (in Polish), 1985.

  • 3. Wołczyński W.: Constrained/unconstrained solidification within the massive cast steel/iron ingots. Archives of Foundry Engineering 10 (2010) 195-202.

  • 4. Lipinski T., Wach A.: Non-metallic inclusions structure dimension in high quality steel with medium carbon contents. Archives of Foundry Engineering 3(9) (2009) 75-78.

  • 5. 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, International Journal of Fatigue 64, (2014) 114–120.

  • 6. Zhang J. M., Zhang J. F., Yang Z. G., Li G. Y., Yao G., Li S. X., Hui W. J., Weng Y. Q.: Estimation of maximum inclusion size and fatigue strength in high-strength ADF1 steel. Material. Science and Engineering A 394 (2005) 126–131.

  • 7. Lipiński T., Wach A.: The Effect of Fine Non-Metallic Inclusions on The Fatigue Strength of Structural Steel. Archives of Metallurgy and Materials 60 (1) (2015) 65-69.

  • 8. Wołczyński W., Guzik E. Wajda W. Jedrzejczyk D. Kania B., Kostrzewa M.: Cet In Solidifying Roll – Thermal Gradient Field Analysis. Archives of Metallurgy and Materials 57 (2012) 105-117.

  • 9. Ulewicz R., Novy F., Selejdak J. Fatigue Strength of Ductile Iron in Ultra-High Cycle Regime. Advanced Materials Research 874 (2014) 43-48.

  • 10. Roiko A., Hänninen H., Vuorikari H.: Anisotropic distribution of non-metallic inclusions in a forged steel roll and its influence on fatigue limit, International Journal of Fatigue 41 (2012) 158–167.

  • 11. Murakami Y., Endo M.: Effects of defects, inclusions and inhomogenities on fatigue strength, International Journal of Fatigue 16 (3) (1994) 163–82.

  • 12. Wang Y., Yang J., Bao Y.: Effects of Non-metallic Inclusions on Machinability of Free-Cutting Steels Investigated by Nano-Indentation Measurements. Metallurgical and Materials Transactions A 46A (2015) 281-292.

  • 13. Lipiński T., Wach A.: The effect of the production process of medium-carbon steel on fatigue strength. Archives of Foundry Engineering 10(2) (2010) 79-82.

  • 14. Ryś J.: Stereologia materiałów (Stereology of materials). FOTOBIT DESIGN, Kraków (in Polish) (1995).

  • 15. Lipiński T., Wach A.: Influence of Outside Furnace Treatment on Purity Medium Carbon Steel. Proc. 23rd Intern. Conf. on Metallurgy and Materials Metal 2014 Brno TANGER Ltd., Ostrava Czech (2014), pp. 738-743.


Journal + Issues