Creep life prediction of a high strength steel plate R. Rajendran a, * , J.K. Paik b , J.M. Lee b , Y.H. Chae b , M.S. Lee c a BARC Facilities, Kalpakkam 603 102, India b Department of Naval Architecture and Ocean Engineering, Pusan National University, 30 Jaengjeon-Dong, Geumjeong-Gu, Busan 609-735, Republic of Korea c POSCO Engineering and Construction Corporation Limited, Pohang 790-704, Republic of Korea Received 23 June 2006; accepted 3 January 2007 Available online 18 January 2007 Abstract Creep life prediction of a high strength steel plate is important in the context of its application as a blast furnace structural element. Numerical analysis using ANSYS was carried out on a high strength steel plate that was simply supported at its one edge and subjected to an in plane constant tensile stress at the opposite edge. Material parameters were derived from the tensile test data and published literature. Bilinear material model and isotropic hardening along with Bailey–Norton time hardening formulation were employed. Sim- ulated creep tests were performed from ambient temperature to temperatures up to 773 K for varying stresses. At the highest operating temperature, it is safe to load the plate up to 55% of its room temperature yield strength but it can survive only nine and half years at 62% of its room temperature yield strength. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Room temperature creep; High temperature creep; Creep strain; Creep rupture life 1. Introduction The brick lining of the blast furnace is encased with high strength steel plate (SM490 in Korean specification) that undergoes thermal and mechanical stresses for a prolonged period of time, which causes time dependent deformation called creep. Due to thermal activation, the steel plate slowly and continuously deforms even under constant load (stress) and eventually fails [1]. Microscopically, there are three dominant mechanisms that cover the creep damage process [1,2]. At high stress (normal stress to shear modulus ratio less than 0.01), dislo- cation glide (involves dislocations moving along slip planes and overcoming barriers by thermal activation) occurs. At intermediate stress (normal stress to shear modulus ratio between 0.01 and 0.0001), dislocation creep (involves the movement of dislocations which overcome barriers by ther- mally assisted mechanisms involving the diffusion of vacan- cies or interstitials) occurs. At low stresses (normal stress to shear modulus ratio less than 0.0001), diffusion creep (involves the flow of vacancies and interstitials through a material under the influence of applied stress) occurs. The most important mechanism in most engineering structures is the dislocation creep [1]. For temperatures below 25% of the absolute melting temperature of the material, primary creep is the dominant deformation mode [3]. At a temperature beyond this range, secondary creep will be remarkably accumulated in the metallic materials [4]. Tertiary creep is unstable in nature wherein the speci- men ruptures due to an infinite elongation (ductile rupture) or the formation of internal cavitation (brittle rupture) [5]. The temperature of the blast furnace shell varies from ambient to 773 K. The steel shell is lined with special bulk ceramic refractory materials that undergo aggressive wear and thermo-mechanical environment. A service life of 15 yr is expected from a relined blast furnace [6]. Furnace repair is impossible during this period because it severely affects the production efficiency. Therefore, the shell has to be investi- gated for its creep strength for this temperature environment. 0261-3069/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.matdes.2007.01.003 * Corresponding author. Tel./fax: +91 44 27480282. E-mail address: rajurajendr@yahoo.co.in (R. Rajendran). www.elsevier.com/locate/matdes Available online at www.sciencedirect.com Materials and Design 29 (2008) 427–435 Materials & Design