Study on Effect of Pressure to Nitrogen Solubility Limit in High Nitrogen Steels

2011 ◽  
Vol 402 ◽  
pp. 169-172
Author(s):  
Shu Huan Wang ◽  
Chen Xiao Li ◽  
Xin Kuo Fang

This paper aims to study the effect of time and pressure on the nitrogen solubility limit through single factor experiment. The experiment is operated in the independent designed device whose main part is high temperature and high pressure reactor, Using high pressure and bottom blowing nitrogen in the furnace, it can gain high nitrogen nickel-free stainless steels whose nitrogen content is more than 1.1%.;The results show that there is solubility limit of nitrogen in 18Mn18CrN steel under certain condition ; The solubility limit of nitrogen in steel increases with the growth of pressure which ranges from 0.4MPa to 1.4MPa.

2013 ◽  
Vol 634-638 ◽  
pp. 3170-3173
Author(s):  
Shu Huan Wang ◽  
Long Chen ◽  
Ding Guo Zhao ◽  
Chen Xiao Li ◽  
Yan Hui Wu

The experiments of smelting high nitrogen nickel-free stainless steel were carried out in the high temperature and high pressure reaction kettle. The nitrogen content was more than 1.36% by using the method of high pressure and bottom blowing nitrogen. With controlling high pressure nitrogen atmosphere and bottom blowing nitrogen, internal react were investigated by single factor experiment. Experimental results shown that there is saturated solubility, while smelting 18Mn18CrN steel with high pressure and bottom blowing nitrogen. Thermodynamic calculation model nitrogen solubility under the condition of high pressure was established, and the influence of nitrogen partial pressure on saturated solubility was researched.


2011 ◽  
Vol 415-417 ◽  
pp. 915-919
Author(s):  
Shu Huan Wang ◽  
Cui Liang Wang ◽  
Ding Guo Zhao ◽  
Ju Gao

The experiments of high nitrogen steels refining have been researched with high pressure and bottom-blown nitrogen in laboratory. We can gain high nitrogen nickel-free stainless steels that its content is more than 0.9%. The research indicates that the temperature influences nitrogen content greatly in the processes of smelting and concreting. The results are shown that saturated nitrogen content in steel increased slightly. When the temperature is as high as 1913K, the nitrogen content can reach 1.191%.


2011 ◽  
Vol 402 ◽  
pp. 202-204
Author(s):  
Ai Min Gao ◽  
Xin Kuo Fang ◽  
Shu Huan Wang

The high nitrogen steel is alloy steel whose nitrogen content is more than solubility limit at atmospheric pressure[1]. Bottom-blowing high-pressure nitrogen smelting nitrogen steel has many advantages, in the paper, from the study of 18Mn18CrN,it can come to a conclusion that in the case of Temperature of 1853K, pressure of 1.0MPa, the bottom-blowing flow of 0.16m3 / h and temperature of 1873K, pressure of 1.4MPa, the bottom-blowing flow of 0.16m3 / h, With the bottom-blowing time of increased the nitrogen content in steel increases, but when the time is more the 10 minutes, the nitrogen content is saturated.


2010 ◽  
Vol 146-147 ◽  
pp. 445-453
Author(s):  
Gang Qiang Jin ◽  
Shu Huan Wang ◽  
Yu Feng Guo ◽  
Xin Sheng Liu

The experimental results on high nitrogen steels refining with high-pressure and bottom-blowing nitrogen were analyzed by the theories of thermodynamics and kinetics in high nitrogen steels smelting. It was shown that nitrogen content in steel increases with the increase of the following factors, that is, pressure, alloying elements (Cr and Mn), bottom-blowing time and bottom-blowing flow. While the nitrogen content in steel decreases with the temperature increase, but it is not obvious. The nitrogen content in steel can also increase with the surface active elements (O and S) decreasing.


2010 ◽  
Vol 146-147 ◽  
pp. 1120-1125 ◽  
Author(s):  
Yu Feng Guo ◽  
Shu Huan Wang ◽  
Gang Qiang Jin

The experiment studied the influence of slag system on nitrogen content in high nitrogen steels which refined by the method of high-pressure and bottom-blowing nitrogen under the conditions of 1.0Mpa. The results shows that nitrogen content are up to 1.0% without the over of slag, and after adding slag, nitrogen content are up to 1.39%; Alkalinity of protecting slag has little effect on the nitrogen content, however, there are very effective to increase nitrogen after using CaF2 instead of SiO2 ,and its nitrogen content are as high as 1.48%; the effect of increasing nitrogen are clear by adding no more than 0.5% pure aluminum, but when aluminum content are more than 0.5%, the nitrogen content in steel are not change significantly, meanwhile, if adding CaF2 slag system, it will be more effective increase nitrogen than only adding pure aluminum.


2012 ◽  
Vol 236-237 ◽  
pp. 163-166
Author(s):  
Shu Huan Wang ◽  
Ding Guo Zhao ◽  
Xiao Jie Cui ◽  
Qiu Jing Li

The method of smelting High nitrogen steels by blowing nitrogen from the device bottom is a promising way of increasing nitrogen with gas. Introduced the device and technical development of smelting High nitrogen steels in domestic and foreign countries, expounded the method and character of dissolving nitrogen into liquid steel at high temperature and high pressure, and analyzed the advantage of increasing nitrogen by bottom-blowing nitrogen. The domestic research is at the developing period of experimental research. The High nitrogen steels which content is more than 1.0% was produced with bottom-blowing nitrogen method at high pressure. The velocity of dissolving nitrogen with bottom-blowing was increased and the smelting time was shortened. The technical effect was very good.


2013 ◽  
Vol 634-638 ◽  
pp. 3110-3113
Author(s):  
Shu Huan Wang ◽  
He Jun Zhang ◽  
Ding Guo Zhao

According to the actual situation of refining high nitrogen steel with the laboratory high pressure reaction axe, the molten steel flow field in the high-pressure and bottom-blowing nitrogen reactor was simulated by using the software Fluent. The rules of the influence of pressure factor on the molten steel flow field characteristics, turbulent kinetic energy and gas content were explored. According to the characteristics of the flow field and gas-liquid two phase structure, the rules of the influence of pressure factor on nitrogen concentration distribution were analyzed. So some useful theoretical basis and guidance were provided for laboratory refining high nitrogen steel and industrial production in the future.


2011 ◽  
Vol 217-218 ◽  
pp. 1185-1190 ◽  
Author(s):  
Wan Ming Li ◽  
Zhou Hua Jiang ◽  
Hua Bing Li

Segregation and liberation occur easily in high nitrogen stainless steels, which can result in the formation of pores and the discarding of the steels. So it is very important to investigate the segregation and liberation theory during the solidification process of high nitrogen stainless steels. In the manuscript, the pouring and solidification progress of high nitrogen steels ingots were simulated through Pro Engineer and PROCAST software. The dynamic variation of temperature field and pressure field were obtained. With the results of PROCAST, the macrosegregation of 20kg weight ingot and 1.7 tons weight ingot were predicted using mathematical model of zone segregation. The predicted results show that 20kg weight ingot has no obvious macrosegregation and 1.7 tons weight ingot has obvious macrosegregation, which is consistent with measuring results. It shows that the accuracy of simulation and calculation to segregation of high nitrogen steels solidification process based on PROCAST software is high.


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