Microstructure and Properties of Grade 700MPa Pressure Vessel Steel with Large Heat Input Welding

Abstract:

The microstructure and properties of grade 700MPa steel with large heat input welding and its heat affected zone (HAZ) were investigated by use of the metallography, scanning electron microscopy, mechanical testing and welding thermal simulation. The results showed that the mechanical properties of the steel meet the technical requirements, namely the yield strength R_eL≥570 MPa, the tensile strength 685MPa≤R_m≤830MPa, the elongation A≥17%, the -20°C impact energy KV₂≥54J and the -20°C impact energy of HAZ≥47J. The steel also had good match between strength, toughness and anti-high heat input welding, the microstructure was tempered sorbite with small dispersed composite inclusions, which promoted the formation of acicular ferrite and were beneficial to the improvement of HAZ toughness.

• Periodical: Applied Mechanics and Materials (Volumes 182-183)
• Pages: 1537-1540
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.182-183.1537
• Online since: June 2012
• Authors: Qing Feng Ding, Tian Sheng Wang, Wen Yan Liu, Xian Jun Wang, Wen Bin Liu, Ming Li
• Keywords: Acicular Ferrite, Large Heat Input, Microstructure, Property Analysis

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