Effect of Alternating Bending and Texture on Anisotropic Damage

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Mechanics, Materials Science & Engineering, September 2016

ISSN 2412-5954

Effect of Alternating Bending and Texture on Anisotropic Damage and Mechanical Properties of Stainless Steel Sheets V.V. Usov1, N.M. Shkatulyak1, E.A. Dragomeretskaya1, E.S. Savchuk1, D.V. Bargan1, G.V. Daskalytsa1 1

South Ukrainian National Pedagogical University named after K.D. Ushinsky, Odessa, Ukraine DOI 10.13140/RG.2.2.35491.04640

stainless steel.

Keywords:

ABSTRACT. Effect of alternating bending and the crystallographic texture on the anisotropy of damage and mechanical properties of stainless steel sheets X5CrNi18-10 at subsequent uniaxial tensile tests were studied. The symmetric tensor of damage of the second order D was used for the analysis of anisotropy damage of sheet material. The only one non-zero component of this tensor D at uniaxial tensile was determined by the defect of the Young's modulus from the mechanical test data. The value of D was found on relation . Here E0 and E and tested material, respectively. It was established the anisotropy of the damage and mechanical properties of steel sheets at uniaxial tensile tests of initial sheet as well of sheets after alternating bending. This anisotropy is caused by the texture that is formed in sheets of investigated steel as was showed by correlation analysis.

Introduction. Stainless steels are widely used in various fields of engineering: architecture, construction, transport engineering, medicine, food industry, energy [1]. An important role is played stainless steel in the petroleum refining [2]. This steel is practically irreplaceable in high-temperature nal forecasting of durability of materials refining industry remains an important problem in relation to the requirements of increasing the depth and quality of oil processing. In the operating conditions under the influence of alternating prolonged loading of equipment inevitably arise damage or irregularities of its working capacity even in the absence of defects in workmanship and compliance in the operation of regulatory requirements. Over last years has been proposed the calculation model of resource estimation of coilpipes furnace of pyrolysis with considering forming quasi-multilayer shell that is formed due the diffusion of carbon in surface layers of steel pipes 20CrNi23-18 at the furnace operation [3]. Articles [4-6] are focused on corrosion and protection from it. The above review shows that proposed methods of predicting damage of structural materials and residual life of process equipment usually are based on monitoring of mechanical properties, metal thickness, morphology and distribution of structural components and structural defects in the steel. It is known that final properties of steel and products depends on many factors such as the chemical composition and its distribution in thickness, metal structure (average size of grains and sub-grains deviousness their borders) [7], crystallographic texture [8], operating temperature, duration of thermal action etc. The emergence during the operation of equipment large number of different defects indicates that is implemented several mechanisms of damage accumulation in metals. In the same time certain characteristics such as crystallographic texture, damage, which could be used for monitoring of the structural condition of the steel rarely taken into account. The impact of above characteristics on corrosion [9] of structural materials requires a more detailed study in terms of degradation and forecasting of metal state. Not investigated also effect of alternating bending (AB) on the anisotropy of damage accumulation in the sheet metal under uniaxial tension. The alternating bending is usually applied before using of roll metal for the straightening of sheets, reducing residual stresses and imparting to the metal of optimal flat characteristics. During the straightening of the metal in him arise and accumulate uncontrollable micro defects, such as micro cracks, micro pores that are found already at tensile on 3-10% [10]. The MMSE Journal. Open Access www.mmse.xyz

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