Formability of friction stir processed low carbon steels used in shipbuilding  

作　　者：D.M. Sekban S.M. Akterer O. Saray Z.Y. Ma G. Purcek 

机构地区：[1]Department of Naval Architecture and Marine Engineering, Karadeniz Technical University, Trahzon, Turkey [2]Department of Autumotive Technology, RecepTayyip Erdogan University, Rize, Turkey [3]Department of Mechanical Engineering, Bursa Technical University. Bursa, Turkey [4]Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China [5]Department of Mechanical Engineering. Karadeniz Technical University, Trabzon, Turkey [6]Engineering Faculty, Giresun University, Giresun, Turkey

出　　处：《Journal of Materials Science & Technology》2018年第1期237-244,共8页材料科学技术（英文版）

基　　金：supported by “The World Academy of Sciences,Italy(TWAS)” under the Visiting Researchers Program of TWASUNESCO Associateship Scheme(Ref.3240260896)

摘　　要：The stretch formability of a low carbon steel processed by friction stir processing （FSP） was studied under biaxial loading condition applied by a miniaturized Erichsen test. One-pass FSP decreased the ferritic grain size in the processed zone from 25 μm to about 3 μm, which also caused a remarkable increase in strength values without considerable decrease in formability under uniaxial loading. A coarse-grained （CG） sample before FSP reflected a moderate formability with an Erichsen index （EI） of 2.73 mm. FSP slightly decreased the stretch formability of the sample to 2.66 ram. However, FSP increased the required punch load （FEI） due to the increased strength by grain refinement. FSP reduced considerably the roughness of the free surface of the biaxial stretched samples with reduced orange peel effect. The average roughness value （Ra） decreased from 2.90 in the CG sample down to about 0.65 μm in fine-grained （FG） sample after FSP. It can be concluded that the FG microstructure in low carbon steels sheets or plates used generally in shipbuilding provides a good balance between strength and formability.The stretch formability of a low carbon steel processed by friction stir processing （FSP） was studied under biaxial loading condition applied by a miniaturized Erichsen test. One-pass FSP decreased the ferritic grain size in the processed zone from 25 μm to about 3 μm, which also caused a remarkable increase in strength values without considerable decrease in formability under uniaxial loading. A coarse-grained （CG） sample before FSP reflected a moderate formability with an Erichsen index （EI） of 2.73 mm. FSP slightly decreased the stretch formability of the sample to 2.66 ram. However, FSP increased the required punch load （FEI） due to the increased strength by grain refinement. FSP reduced considerably the roughness of the free surface of the biaxial stretched samples with reduced orange peel effect. The average roughness value （Ra） decreased from 2.90 in the CG sample down to about 0.65 μm in fine-grained （FG） sample after FSP. It can be concluded that the FG microstructure in low carbon steels sheets or plates used generally in shipbuilding provides a good balance between strength and formability.

关 键 词：Friction stir processing Low carbon shipbuilding steel Formability Microstructure Mechanical properties 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG453.9[金属学及工艺—金属材料]