Laser penetration welding of ship steel EH36: A new heat source and application to predict residual stress considering martensite phase transformation. (September 2018)

• Record Type: Journal Article
• Authors: Rong, Youmin; Mi, Gaoyang; Xu, Jiajun; Huang, Yu; Wang, Chunming
• Is Part Of: Marine structures. Volume 61(2018)
• Page Start: 256
• Page End: 267
• Publication Date: 2018-09
• Subjects: Laser penetration welding -- Heat source model -- Residual stress -- Martensite phase transformation; Naval architecture -- Periodicals; Offshore structures -- Periodicals; Architecture navale -- Périodiques; Structures offshore -- Périodiques; Naval architecture; Offshore structures; Periodicals; 620.4162
• DOI: 10.1016/j.marstruc.2018.06.003
• Languages: English
• ISSNs: 0951-8339

Abstract

Abstract: A weld profile with an accurate distribution of the temperature field is very difficult to simulate, especially for laser penetration welding. In this paper, a peak index increment-double cone heat source model was proposed for laser penetration welding of ship steel EH36. This heat source model was proposed considering the actual weld profile with a geometry of a "V" combined with an inverted "V"; the adjustment parameter was rapidly selected by a simplified linear interpolation method, and the validity of this model was proven by experimental results with an average error of 11.12%. Microstructures of the weld zone, which included ferrite and martensite, were then analysed. Considering the influence of the martensite phase transformation on the strain increment, the distribution of residual stress was simulated by loading the proposed heat source model; the peak values and the high gradient behaviour of the residual stress were intensified. The proposed heat source model was proven to be valid and was applied to predict the residual stress; it can be further used in other welding processes with different metal materials. Graphical abstract: Image 1 Highlights: Butt joint of ship steel EH36 is obtained by laser penetration welding. A peak index increment-double cone heat source model is proposed considering the actual beam profile. The proposed model is used to simulate residual stress considering martensite transformation.