A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Masthanaiah, P.
- Laser Welding of Ultrafine Bainitic Steels
Authors
1 Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad - 500 075, IN
2 School of Engineering Sciences and Technology, University of Hyderabad - 500 046, IN
3 Defence Metallurgical Research Laboratory, Hyderabad - 500 058, IN
4 Defence Research Development Laboratories, Hyderabad - 500 058, IN
5 Ministry of Steel Chair Professor, MGIT, Hyderabad - 500 075, IN
Source
Indian Welding Journal, Vol 52, No 3 (2019), Pagination: 52-56Abstract
Laser beam welding (LBW) is one of the advanced welding process which results in joining of materials with intense heat. The intense heat is produced using focused light source falling upon the metallic material’s surfaces to be welded. The coherent laser beam is a known source of electromagnetic energy or light with single frequency which can be projected without diverging and also can be focused to an exact spot. The current investigation aims at establishing the parameters required for producing sound welds by fibre laser beam welding and identifying the evolution of microstructure in bainitic steel during similar welding of three mm thick plates. Sound welding was accomplished with laser power 3.5kW and at traverse speeds of 2000, 3000 and 4000 mm/min. The weld joints revealed base metal, weld zone and heat affected zones. The widths of weld zone and HAZ varied as a function of welding speed. Weld zone displayed hardness around 750-800 VHN. A sudden drop in hardness was observed across the heat affected zone, reaching a dip in the intercritical region of HAZ. Hardness in ICHAZ reached around 400-450VHN. The ICHAZ was more pronounced at 3000 mm/min. Microstructural changes were explored by optical microscopy techniques. The high hardness in fusion zone and low hardness in the intercritical structure was found to have correlation with prevailing microstructural features in the respective zones.
Keywords
Bainitic Steel, Fibre Laser Welding, Fusion Zone, Heat Affected Zone, Intercritical Structure, Hardness.
References
- Das S and Haldar A (2014); Continuously cooled ultrafine bainitic steel with excellent strength-elongation combination, Metallurgical and Materials Transactions A, 45A, pp.1844-1854.
- Manugula VL, Rajulapati KV, Reddy GM, Mythili R and Sankara Rao KB (2016); A critical assessment of the microstructure and mechanical properties of friction stir welded reduced activation ferritic-martensitic steel, Material and Design, 92, pp.200-212.
- Feng Z, Hoelzer D, Sokolov MA and Tan LT (2013); Friction stir welding of ODS steels and advanced ferritic martensitic steel, Oak Ridge National Laboratory Fusion Reactor Materials Program, 54.
- Steen WM (1999); Laser material processing, Springer-Verlag London, pp.113-116.
- Akbari Mousavi SAA and Sufizadeh AR (2010); Metallurgical investigations of pulsed Nd:YAG laser welding of AISI 321 and AISI 630 stainless steels, Journal of Materials and Design, 30, pp.3150–3157.
- Takahashi M and Bhadeshia HKDH (1990); Model for transition from upper to lower bainite, Materials Science and Technology, 6, pp.592-603.
- Torkamany MJ, Tahamtan S and Sabbaghzadeh J (2010); Dissimilar welding of carbon steel to 5754 aluminum alloy by Nd:YAG pulsed laser, Materials and Design, 31, pp.458-465.