Optical laser welding Q235 steel joint structure and performance under different cooling conditions. (November 2015)

• Record Type: Journal Article
• Authors: Guo, C.; Lu, Q. H.; He, X. F.; Peng, B. R.; Guo, Y.
• Is Part Of: Materials research innovations. Volume 19(2015)Supplement 9
• Page Start: S9-82
• Page End: S9-87
• Publication Date: 2015-11
• Subjects: Air-cooling -- Water-cooling -- Welding with optical fibre laser -- Grain structure analysis -- Laser welding; Materials -- Research -- Periodicals; Matériaux -- Recherche -- Périodiques; 620.1105
• DOI: 10.1179/1432891715Z.0000000001925
• Languages: English
• ISSNs: 1432-8917

Abstract

Abstract : In this paper, fibre laser is used in welding Q235 steel test. Both properties of metallographic structure and micro-hardness in weld metal and heat-affected zone are analysed separately in air-cooling and water-cooling conditions. The results show that the weld width in water-cooling condition is narrower than the weld width in air-cooling condition. The metallographic structure of weld metal after both air-cooling and water-cooling conditions is composed of ferrite and pearlite. However, the crystal grain is relatively larger with air-cooling and the eutectoid ferrite is separated out as massive texture. In contrast, the columnar crystal in weld metal is long and thin with water-cooling. The eutectoid ferrite is separated out in the form of flakes, and fewer widmanstätten structures appear simultaneously. The weld metal hardness after water-cooling is slightly higher than that of the weld metal after air-cooling.