Brittle crack arrestability of thick steel plate welds in large structure

摘要

Recently, there has been such a critical issue in shipbuilding industry that much larger and stronger ships are required to develop oil and gas in the Arctic region. Attention has been paid to obtaining high strength, good toughness at low temperature, and good weldability. An experimental study was performed to evaluate the brittle crack arrest toughness value (K_ca) and brittle crack arrest method of welded joints using EH40 grade steel with a thickness of 80 mm. The test specimens were made by both flux cored arc welding (FCAW) and combined welding (EGW+FCAW) processes. Temperature gradient ESSO test was performed to measure the Kca of the base metal. Also, a constant temperature (−10 °C) ESSO test was performed to establish a brittle crack arrest method using high toughness welding consumable with real structural specimens. The research aims in this study were to investigate the effect of joint design and welding consumable for the crack arrestability of thick steel plates using EH40 grade shipbuilding steel of straight block joint weld line with two kinds of welding processes.