JIANG Zhouhua
,
DONG Yanwu
,
LIANG Lianke
,
LI Zhengbang
钢铁研究学报(英文版)
The pickup of hydrogen during electroslag remelting process for several slags consisting of CaF2Al2O3CaOSiO2MgO had been investigated. The laboratoryscale remelting experiments had been carried out in open air and waterfree argon atmosphere, and then the influencing factors were analyzed. It had been found that the hydrogen content in steel varied with different slag compositions. The compositions and state of slag had significant effect on the hydrogen level in steel. Partial return slag and premelted slag could avoid the hydrogen pickup especially in the early stages of the process. However, premelted slag was the optimum state to control the hydrogen pickup in steel. Experimental results indicated that waterfree argon atmosphere was very favorable to the control of hydrogen in steel in the normal remelting period.
关键词:
electroslag remelting; hydrogen; calcium fluoride; premelted slag; protective atmosphere
CHANG Lizhong
,
SHI Xiaofang
,
YANG Haisen
,
LI Zhengbang
钢铁研究学报(英文版)
The effect of frequencies of AC power supply on the quality of the electroslagmelted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the temperature in the slag bath becomes more homogeneous, and therefore, the depth of molten metal pool is decreased; electrochemical reactions occur with the decrease in the frequency, and the atomic oxygen electrolyzed dissolves in the molten metal pool; the nonmetallic inclusions, which are distributed dispersively in the ingot, have an increased content, and their size is approximately in the range of 2-3 μm.
关键词:
electroslag remelting;lowfrequency AC power supply;molten metal pool;oxygen;electrolytic reaction
DONG Yanwu
,
JIANG Zhouhua
,
LI Zhengbang
钢铁研究学报(英文版)
Experiment was carried out after the process parameters were calculated by the model previously established. The relationship between interdendritic spacing and local solidification time (LST) mainly determined by process parameters was exposed. Furthermore, the extent of segregation was studied. The results indicate that LST and interdendritic spacing are the largest and the amount of Laves phase as a result of the niobium segregation is the highest in the center of the ingot, whereas the opposite results are obtained at the edge of ingot. The extent of element segregation and the amount of Laves phase can be reduced when appropriate parameters are used. Therefore, the duration of subsequent homogenization treatments for 718 is shortened and the alloy quality is improved.
关键词:
electroslag remelting;Inconel 718;segregation;local solidification time;interdendritic spacing
