Vol.10, No2, 2010, pp.89-94
UDC  620.17 :  669.15  539.431.013.3


Rozina Yordanova1, Donka Angelova1, Zoya Naydenova1,

Angelina Stoyanova-Ivanova2, Valdek Mikli3

1) University of Chemical Technology and Metallurgy, Sofia, Bulgaria

2) Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia, Bulgaria

3) Centre for Materials Research, Tallinn Technical University, Tallinn, Estonia


Short crack propagation behaviour of a low-carbon low-alloyed construction steel, ROLCLAS 09G2 is investigated under stress ranges  = 500; 540; and 580 MPa and testing frequency f = 11 Hz at rotating-bending fatigue. The applied loading scheme is symmetric with a loading ratio R = –1. Two groups of specimens without and with a layer are tested in air. All fatigue tests are carried out on a table model Fatigue Rotating Bending Machine, FATROBEM-2004 at UCTM–Sofia, Bulgaria. Short fatigue crack growth behaviour of ROLCLAS 09G2 in-air is presented in plots “Crack lengths, a, against corresponding numbers of cycles, N”, for the two groups of specimens and compared graphically and microstructurally. The specific band structure of ROLCLAS 09G2 makes it possible to use the steel as a modelling material in relation to composite materials.

Keywords: crack propagation, low-carbon low-alloyed steel, rotation bending fatigue, band structure

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