Agricultural Engineering, Volume 48 (2016)


Tomasz Lipiński, Anna Wach
University of Warmia and Mazury in Olsztyn, The Faculty of Technical Sciences


The influence of impurities on fatigue strength has been researched extensively, but very few studies analyze the effect of impurities on the coefficient given by equation (1) which is used to estimate fatigue strength (zgo)based on Vickers hardness (HV), i.e. in non-destructive tests. Coefficient k is the quotient of fatigue strength zg divided by Vickers hardness HV.

The article discusses the results of a study investigating the effect of the percentage volume of non-metallic inclusions on the fatigue strength coefficient of structural steel during rotary bending. The study was performed on heats produced in an industrial plant. Fourteen heats were produced in an electric furnaces and oxygen converter. All heats were desulfurized. A half of heats from electrical furnaces were refined with argon, and heats from the converter were subjected to vacuum circulation degassing.

Steel were hardened and tempered at different temperatures. The results were presented graphically, and the fatigue strength coefficient of steel with a varied share of non-metallic inclusions was determined during rotary bending. The results revealed that fatigue strength coefficient is determined by the percentage volume of non-metallic inclusions and tempering temperature.

Keyword(s): Steel, structural steel, non-metallic inclusions, fatigue strength, fatigue strength coefficient, bending fatigue, bending pendulum


T.Y.Shish, T.Araki. The effect of non metallic inclusion and microstructures on the fatigue crack initiation and propagation in high strength carbon steel.Trans.Iron. Steel Inst.Jap. 1973, 1, 11-19p.

C.W.Anderson, G.Shi, H.V.Atkinson,C.M.Sellars. The precision of methods using the statistics of extremes for the estimation of the maximum size of inclusions in clean steels, Acta Materialia, 2000, 48(17), 4235-4246p.

M.A.Miner. Cumulative damage in fatigue. Trans. ASM 1945, 65, 159-165p.

Kocańda, S. 1985. Zmęczeniowe pękanie metali, WNT Warsaw (in Polish).

B.Pyttel, D.Schwerdt, C.Berger. Very high cycle fatigue – Is there a fatigue limit? International Journal of Fatigue, 2011, 33, 49–58p.

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

S.Kocańda, J. Szala. 1985. Basis of fatigue calculation. PWN Warsaw (in Polish).

T.Lipiński. The influence of the distribution of nonmetallic inclusion on the fatigue strength coefficient of high purity steels. Journal of Achievements of Materials and Manufacturing Engineering 2015, 69(1), 18-25p.

J.Ryś. 1995. Stereology of materials. FOTOBIT DESIGN, Krakow (in Polish).

Full Text: PDF


  • There are currently no refbacks.

Agricultural Engineering ISSN 1392-1134 / eISSN 2345-0371

This journal is published under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License. Responsible editor: Dr A. Žunda.