The Sterophotogrammetrical reconstruction of crack topography in Cr-Al-Mo nitrided steel and determination of condition at the crack front of sub-surface iniateted crack

Abstract This article deals with problem of determination condition at the crack front specimens nitrided surface layer. The conditions is realized using HRR theory stress field. COD obtained by fractographic analysis were used as input values for calculations method determining was applied to samples fatigue crack, loaded Push-pull mode and further torsion, bending their combination. 3D reconstruction fracture stereophotogrammetry. In order verify effectiveness applicability method, measurements performed on without a layer also included in analysis. Experimental work has shown that described can determine front, however, much more suitable than samples. probably due fact it easier measure this case.