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Wu Zhisheng
Liu Cuirong
Wang Jiuhai
School of Materials Science,
Taiyuan University of Science
and Technology,
Taiyuan 030024, China
Shan Ping
Hu Shengsun
Lian Jinrui
School of Materials Science,
Tianjin University,
Tianjin 300072, China |
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MICROSTRUCTURE
AND PROPER- TIES OF DEEP CRYOGENIC TREATMENT ELECTRODES FOR SPOT
WELDING HOT DIP GALVANIZED STEEL*
Abstract:
The microstructure and elements distribution of the deep cryogenic treatment electrodes and non-cryogenic treatment electrodes for spot welding hot dip galvanized steel are observed by a scanning electrical microscope. The grain sizes, the resistivity and the hardness of the electrodes be-fore and after deep cryogenic treatment are measured by X-ray diffraction, the DC double arms bridge and the Brinell hardness testing unit respectively. The spot welding process performance of hot dip galvanized steel plate is tested and the relationship between microstructure and physical properties of deep cryogenic treatment electrodes is analyzed. The experimental results show that deep cryogenic treatment makes Cr, Zr in deep cryogenic treatment electrodes emanate dispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non-cryogenic treatment ones so that the electrical conductivity and the thermal conductivity of deep cryogenic treatment electrodes are improved very much, which make spot welding process performance of the hot dip galvanized steel be improved.
Key words:
Deep cryogenic treatment Electrodes Microstructure Spot welding Galvanized steel |