SUN Li-yuan
,
LI Jing-she
,
ZHANG Li-feng
,
YANG Shu-feng
,
CHEN Yong-feng
钢铁研究学报(英文版)
To replace nickel-based stainless steel, a nitrogen-bearing stainless steel was produced to lower the production cost stemming from the shortage of nickel recourses. Thermodynamic model to calculate the saturated nitrogen content in the stainless steel was developed and the model was validated by experimental measurements performed with a high temperature induction furnace. Nitrogen gas under constant pressure was injected into the molten steel with a top lance. Thus, the nitrogen was transferred to the molten stainless steel. The effects of chemical composition, temperature, superficial active elements and nitrogen flow rate on the transfer of nitrogen to the steel were investigated and discussed. The results showed that the dissolution rate of nitrogen in the molten steel increases with a higher temperature and larger nitrogen flow rate but decreases significantly with an increase in the content of surface-active elements. Alloying elements such as chromium and manganese having a negative interaction coefficient can increase the dissolution of nitrogen in the molten steel. It was also proposed that the primary factor affecting the final saturated nitrogen content is temperature rather than the dissolved oxygen content.
关键词:
nitrogen-bearing stainless steel
,
nitrogen
,
thermodynamic modeling
YANG Shu-Feng LI Jing-feng
,
ZHANG Li-feng
,
et al
钢铁研究学报(英文版)
The transformation of MgO•Al2O3 based inclusions in alloy steel during refining has been studied by industrial trials. Besides Factsage software is applied to study the formation and modification of spinel inclusions in alloy steel using calcium treatment during refining process. The results show the transformation sequence of inclusions is: MgO•Al2O3 → CaO–Al2O3–MgO complex inclusions → MgO•Al2O3; In order to avoid forming MgOAl2O3 inclusions, the content of dissolved Ca in the molten steel has to reach 1ppm.
关键词:
Alloy steel;Non-metallic inclusions;MgO•Al2O3 spinel;Thermodynamics
