Analysis of the Surface Defects in a Hot-Rolled Low-Carbon C–Mn Steel Plate
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In the present study, a microstructural investigation was conducted on surface defects occurring in a 28 mm thick low-carbon C–Mn steel plate with ferrite–pearlite microstructure. The plate contained transverse “scraped-out”-like defect at the top surface edge and a continuous longitudinal “V-groove”-like defect throughout the length of the plate in the bottom surface. Detailed microstructural analyses showed formation of several small as well as long shallow unidirectional unbranched cracks with oxide entrapments in the defect region at the top surface associated with partial decarburization and internal oxidation confirming its genesis at the casting stage. On the other hand, extensively branched “stag deer horn” crack heavily filled with compact FeO oxide scale originated from the bottom surface defect with no microstructural abnormality confirmed that the groove existed before the hot rolling operation and the cracks formed during the rolling under differential loading.
KeywordsSurface defect Low-carbon steel plate Hot rolling Oxide scale Crack
The authors are thankful to the Management of R&D Centre for Iron and Steel (RDCIS), Steel Authority of India Limited (SAIL), Ranchi, India, for their support and encouragement in pursuing this work. Heartfelt thanks are due to Mr. J. Guria for his assistance in optical and scanning electron microscopy job.
- 2.H. Jia, Y.L. Murphey, J. Shi, T.S. Chang, An intelligent real-time vision system for surface defect detection, in Proceedings of 17th International Conference on Pattern Recognition, ICPR 2004, vol. 3 (2004), pp. 239–242Google Scholar
- 3.S. Kling, Advanced process and quality control in hot rolling mills using eddy current inspection, in CD Proceedings of 9th European Conference on NDT, ECNDT 2006, Berlin, Germany, We.1.8.3, pp. 1–7Google Scholar
- 8.I. Mamuzić, M. Longauerova, A. Štrkalj, The analysis of defects on continuous cast billets. Metalurgija 44(3), 201–207 (2005)Google Scholar
- 9.A.W. Cramb, The making, shaping and treating of steel, 11th edn. Casting, The AISE Steel Foundation Pittsburgh, Pa, 2003, ISBN: 0-930767-04-7Google Scholar
- 10.M. Masarik, L.Čamek, J. Duda, Causes of occurrence of internal and surface defects at continuous casting of steel slabs and possibilities of their removal, in Proceedings of 23rd International Conference on Metallurgy and Materials METAL 2014, Brno, Czech Republic, EU, May 2014, pp. 105–110, ISBN 978-80-87294-54-3Google Scholar
- 15.R. Manojlovic, R. Ilievski, Influence of the processing conditions on the hot-rolled manganese steel sheet surface quality. TEM J. 2(2), 166–169 (2013)Google Scholar
- 16.L. Suarez, J. Schneider, Y. Houbaert, Effect of Si on high-temperature oxidation of steel during hot rolling. Defect Diffus. Forum 273–276, 655–660 (2008)Google Scholar
- 18.Verein Deutscher Eisenhüttenleute (VDEh) (ed.), Surface Defects in Hot Rolled Flat Steel Products, 2nd edn. (Stahl and Eisen, Dusseldorf, 1996)Google Scholar
- 21.S.K. Ray, Surface Quality of Steel Products: Role of Chemistry, Steel Making and Continuous Casting, 1st edn. (Allied Publishers Pvt. Ltd., 2005)Google Scholar