Metallurgical aspects in laser welding of steels and aluminum alloys
- Nagoya Univ. (Japan)
Rapid cooled microstructures, solid state transformation, hardness distribution, porosity formation, hot cracking and crack susceptibility are discussed as the metallurgical aspects in laser welding of carbon steels, stainless steels and aluminum alloys in the present paper. In the cases of CO{sub 2} and YAG laser welding, the thermal cycles during welding of carbon steels showed a rapid heating rate of 10{sup 5} K/s and a rapid cooling rate of 10{sup 4} K/s. The solid state transformations during the thermal cycle are different from that in steel welds by arc. The microstructure in heat affected zone consists of ferrite band or matrix and hard martensite colonies with high carbon. It seems a kind of composite materials. The hardness distribution of steel welds by laser is different from that of arc welds in which the location of maximum hardness is coarse grain zone. However, it is the center of fusion zone or near the base metal in laser welds of carbon steel. Even in ultra low carbon steel welds, the hardness of weld metal is higher than 200 Hv and the microstructure is bainitic ferrite and low carbon martensite which have a low cold crack susceptibility. In addition, two mechanisms of porosity formation in laser welding of aluminum alloys including A3003, A5052, A5083, A5182 and A6061 alloys were investigated using the fundamental knowledge and the solidification crack susceptibility in laser welding of A5052, A5083, A6061 and A7NO1 alloys were studied for the application of laser welding in industries.
- OSTI ID:
- 539339
- Report Number(s):
- CONF-961073-; TRN: 97:003387-0065
- Resource Relation:
- Conference: ICALEO `96: 15. international congress on applications of lasers and electro-optics, Detroit, MI (United States), 14-17 Oct 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the laser materials processing conference - ICALEO `96. Volume 81; PB: 971 p.
- Country of Publication:
- United States
- Language:
- English
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