The Properties of Low Yield Ratio and High Heat Input Welding Construction Steel and the Microstructure of HAZ

• Published in: Applied Mechanics and Materials Vol. 490-491; no. Mechanical Design and Power Engineering; pp. 69 - 72
• Main Authors: Tang, Meng Xia, Chen, Xiao, Bu, Yong, Wu, Run, Duan, Dong Ming
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.01.2014
• Subjects: Ferrite; Heat affected zone; Inclusions; Microstructure; Structural steels; Titanium; Toughness; Welding; Acicular Ferrite; Low Yield Ratio; Heat Affected Zone; Inclusion; High Heat Input
• ISBN: 303835001X; 9783038350019
• ISSN: 1660-9336; 1662-7482; 1662-7482
• DOI: 10.4028/www.scientific.net/AMM.490-491.69

Steel with low yield ratio (YR0.75) and high heat input welding was made by combining Zr, Ti microalloying. Its microstructure investigated by optical and electron microscopes (SEM, TEM), consists of ferrite with the fine pearlite which not only ensures the high strength and toughness but also decreases the yield ratio. The steel was simulated in 100 kJ/cm heat input welding. The microstructures for heat affected zone (HAZ) of weldments mainly consisted of acicular ferrites which nucleate on fine Zr and Ti contained inclusions. The acicular ferrites decrease detrimental influence of grain coursing in the HAZ and make the steel good toughness in low temperature.