Fatigue short crack growth, model and EBSD characterization of marine steel welding joint. (March 2022)

• Record Type: Journal Article
• Authors: Su, Molin; Xu, Lianyong; Peng, Chentao; Han, Yongdian; Zhao, Lei
• Is Part Of: International journal of fatigue. Volume 156(2022)
• Publication Date: 2022-03
• Subjects: Short crack -- Fatigue fracture -- Stress intensity factor -- Dislocation density -- EBSD pattern; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2021.106689
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Crack transition length concept was induced to divide short crack of EH36 joints into 3 stages. EBSD pattern was conducted to characterize strain hardening gradient and fracture mode. A novel segmented model was proposed to describe the whole short crack propagation. Abstract: Aiming at short crack (SC) behavior whose growth rate ( da/dN ) decreased firstly and subsequently increased with the rise of SC in EH36 steel, the crack transition length ( a t ) concept was introduced to divide SC into 3 stages: microstructurally short crack (0– a t ), transition zone ( a t –0.5 mm) and physically short crack (0.5–1.5 mm). Then geometrically necessary dislocation density was utilized to reveal strain hardening gradient effect on SC behavior. Eventually, considering crack closure, the effective stress intensity factor range ( ΔK eff ) and the ΔK eff when SC was equal to a t ( ΔK at ) were obtained to form a segmented model to demonstrate da/dN of whole SC.