Heat treatment mode optimization of dissimilar weld joints of EP517 steel to 36NKhTYu alloy
Abstract
The paper presents the results of a heat treatment impact on the weld metal hardness of EP517 steel to 36NKhTYu alloy dissimilar welded joints. Aging curves for the weld metal in the temperature range from 600°C to 750°C and with an aging time of up to 64 hours are performed. Metallographic researches of weld metal and heat-affected zone (HAZ) are carried out. It was established that the greatest increase of hardness is reached after the exposure for 32 hours at 650°C and after the exposure for 16 hours at 700°C. It was found that after the aging with the specified conditions, weld metal hardness increases by 36% (60 HV) in comparison with its hardness after welding. The microstructure research showed that the decomposition fraction of supersaturated solution in HAZ of 36NKhTYu alloy significantly depends on the temperature and reaches its ultimate value after the aging at a temperature of 700°C.
- Publication:
-
Materials Science and Engineering Conference Series
- Pub Date:
- February 2020
- DOI:
- 10.1088/1757-899X/759/1/012024
- Bibcode:
- 2020MS&E..759a2024T