Influence of Microstructures on Polarization Resistance and Hydrogen-Induced Cracking of a Micro-Alloyed Steel Submitted to Different Cooling Rates

作     者：González M R Martins de Araújo D S Goldenstein H Alonso-Falleiros N 

作者机构：Departamento de Engenharia Metalúrgica e de MateriaisEscolaPolitécnicaUniversidade de Sao Paulo-SP-Brasil 

出 版 物：《Journal of Iron and Steel Research International》 (钢铁研究学报(英文版))

年 卷 期：2011年第18卷第S1期

页      面：168-172页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：hydrogen induced cracking polarization resistance micro-alloyed steel control cooling 

摘      要：The effect of different microstructures on the polarization resistance (Rp) and the hydrogen-induced cracking (HIC) of a micro-alloyed steel austenitized and submitted to different cooling rates was *** 19.1 x 6 x 2 mm,containing the whole thickness of the plate were extracted from a 20 mm plate and heat treated on a quenching dilatometer,were submitted to Rp and HIC corrosion *** Rp and HIC tests followed as close as possible ASTM G59 and NACE standard TM0284-2003,in this case,modified only with regard to the size of the *** samples transformed from austenite by a slow cooling (cooling rate of 0.5℃.s-1) showed higher susceptibility to hydrogen-induced cracking,with large cracks in the middle of the sample propagating along segregation bands,corresponding to the centerline of the plate *** cooling rates of 10℃.s-1,only small cracks were found in the matrix and micro cracks nucleated at non-metallic *** higher cooling rates (40℃.s-1) very few small cracks were detected,linked to non-metallic *** result suggests that structures formed by polygonal structures and segregation bands (were eutectoid microconstituents predominate) have higher susceptibility to *** predominantly formed by acicular ferrite make it difficult to propagate the cracks among non-oriented and interlaced acicular ferrite *** segregation bands containing eutectoid products also help inhibit cracking and crack propagation;segregation bands can function as pipelines for hydrogen diffusion and offer a path of stress concentration for the propagation of cracks,frequently associated to non-metallic *** resistance essays performed on the steel in theas received condition,prior to any heat treatment,showed larger differences between the regions of the plate,with a considerably lower Rp in the *** austenitization heat treatments followed by cooling rates of 0.5 e 10℃.s-1 made more uniform the