Residual stress investigation of welded high strength steel box T-joints

摘要

An experimental investigation to determine the residual stress distributions at the chord weld toernof two welded High Strength Steel (HSS) boxT-joints is described in this paper.Two identical specimens with thernsame geometrical size were fabricated to investigate the influence of preheating on the residual stress magnitudernand distribution of HSS welded box T-joint. One specimen was welded at ambient temperature while the otherrnone was preheated to 100?C before the welding. Following the AmericanWelding Society (AWS) standard, thernbrace and chord boxes were both fabricated from Reheated, Quenched and Tempered (RQT) high strength steelrnplates with nominal yield stress of 690MPa using Flux-Cored ArcWelding (FCAW). The residual stress near thernchord weld toe of the joints was measured by the incremental hole-drilling method according to the AmericanrnSociety for Testing and Materials (ASTM) standard E837-08. By comparing the measured results obtained fromrnthe two specimens, it is found that preheating can effectively reduce the magnitude of residual stress inducedrnby welding. The residual stress magnitude also showed significant variations at different locations along therncircumferential direction of the welded joint.