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Zhouhua Jiang Huabing Li Zhaoping Chen Zongze Huang Deling Zou Lianke Liang 《国际钢铁研究》2005,76(10):740-745
Nitrogen solubility in the austenitic stainless steel melts was measured in the laboratory by bubbling nitrogen gas under different partial pressures of nitrogen and temperatures. A new thermodynamic model for the calculation of nitrogen solubility in molten stainless steel in a wide range of alloy concentrations, temperatures, and pressures has been successfully established by introducing a new term for the effect of pressure on the nitrogen activity coefficient. The calculation results were in good agreement with the measured values. The influences of temperature, nitrogen partial pressure and chemical composition on the nitrogen solubility in molten stainless steel are discussed based on the calculated results. It is possible to produce high nitrogen steels at normal pressure by optimizing the design of the alloy composition and controlling the lowest melting temperature from a thermodynamic point of view. 相似文献
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高氮不锈钢研究的发展近况 总被引:4,自引:0,他引:4
介绍了国内外高氮不锈钢研究近期的成果,内容涉及高氮不锈钢基础研究、力学性能、耐腐蚀性能、焊接性及高氮不锈钢新材料,反映了国内外高氮不锈钢研究的发展状况.鉴于高氮不锈钢卓越的综合性能而国内高氮钢研究已远远落后于国际发展水平的现状,应尽快在国内建立高氮钢试验装置,加快国内高氮不锈钢基础理论、生产工艺技术(特别是冶炼技术)和新材料的研究,把握不锈钢发展的方向,为中国不锈钢的发展提供有力的支持. 相似文献
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文章介绍了八钢公司采用铁水脱硫预处理、复吹转炉、LF精炼、板坯连铸工艺开发X60管线钢的过程。在成分设计上应用了Nb、V、Ti微合金化,采用低碳含量,提高产品的韧性和延性,同时具有良好的焊接性能。将Nb、V、Ti微合金化与热机械轧制工艺(TMCP)相结合,充分应用管线钢的晶粒细化、固溶强化、析出强化和相变强化等机制,提高管线钢的强度和韧性。采用微钛处理技术,改善管线钢焊接热影响区的韧性。生产控制上采用纯净钢冶炼工艺和连铸的保护浇铸工艺,降低钢中的氮含量、非金属夹杂和硫含量,并对钢水中的Al2O3夹杂进行钙处理,提高管线钢热轧卷板的断裂韧性。采用该工艺生产的X60管线钢成品[S]≤0.0050%,[N]≤0.0055%,钢中的A、B、C、D各类夹杂物能控制到1.5级以下。钢材的抗拉强度控制在550~670 MPa,屈服强度控制在475~545 MPa,屈强比控制在0.82~0.90,断后伸长率控制在35%~43.5%,-20℃夏比V型横向冲击功AkV88~112 J,各项力学性能完全满足国内外标准和用户技术条件要求,已形成批量供货能力。 相似文献
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在高温高压反应釜内冶炼Cr12N高氮钢,通过试验发现,在Cr12N的熔炼过程中,随着压力的提高,钢中的氮含量不断增加,钢锭中得到的固相中氮的饱和溶解度和Chipman等人的热力学模型计算得到的氮的饱和溶解度有一定的偏差,为了修正这个偏差,引进了Burton-Prim-Slichter方程,修正后得到液相中氮的饱和溶解度的修正值和计算值吻合得很好。计算了在Cr12N的冶炼过程中,防止气泡析出所需要的最小凝固压力为2.84 MPa,通过试验发现,在高的凝固压力下,钢锭的致密性和缩孔现象得到明显改善。 相似文献
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Nitrogenelementexistsinsteelassolidsolu-tionornitride.Thequalityandtheperformanceofsteelareobviouslyafectedbynitrogen.Thetoug... 相似文献
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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. 相似文献
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氮气加压熔炼高氮钢若干理论问题探讨 总被引:5,自引:0,他引:5
导出了氮在铁合金溶液中的溶解度模型,探讨了表面活性元素对吸氮过程的影响,且对含氮铁合金溶液的凝固过程、氮的偏析及保持氮在熔体中的最小压力进行了精确解析。 相似文献
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Zhong-ping SHI Zhen-hua WANG Shu-hua SUN Ze-an ZHOU Ying-ping GUAN Wan-tang FU 《钢铁研究学报(英文版)》2014,21(10):945-950
The phase diagram of an Nb- and V-containing 18Mnl8Cr0.5N steel was investigated using thermodynam ic calculation. The compositions and characteristics of precipitates were investigated by scanning electron microsco- py, energy dispersive spectrometry, X-ray diffraction, and differential scanning calorimetry. Under equilibrium con- ditions, MX precipitates at 1 350 ℃. MX is a substitutional solid solution of Nb4 N3.38, and its composition (at. %) is approximately.. Nb 40, N 40, V 8, and Fe, Cr, and Mn balance. The precipitates, with shapes including irregular bulk, rod, and ellipsoid, are primarily distributed at grain boundaries and triple junctions, and their size is approxi- mately 5 10 μm. Finally, the microalloying of high nitrogen CrMn austenite steels, control of precipitate size, and the effect of precipitate on hot formin~ were discussed. 相似文献
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《钢铁研究学报(英文版)》2016,(7):647-654
The effects of some key factors on nitrogen absorption during the smelting process of X70 pipeline steel were studied,and the source of nitrogen pick-up was analyzed to find the bottleneck for nitrogen control.A series of measures were put forward to decrease the nitrogen pick-up.The results indicated that an exponential relationship existed between the nitrogen absorption index and the free oxygen in molten steel.Nitrogen absorption index could decrease below 0.3when free oxygen in molten steel was above 100×10~(-6) after tapping.For low sulfur killed steel,the nitrogen absorption ratio and sulfur content satisfied a linear relationship with a slope of-0.007.Low free-oxygen and sulfur were beneficial to the deep desulfurization during vacuum treatment.The contradiction of high desulfurization ratio and low nitrogen pick-up during LF process could be resolved by skimming oxidizing slag after tapping and making new high basicity top slag.After optimization,the average content of nitrogen in final product decreased from 46×10(-6)to 35×10(-6). 相似文献
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从成分控制、热轧和热处理等角度出发,综合研究双相不锈钢S32101的生产工艺并进行优化调整,分析生产试验数据。研究分析表明:在1050~1150℃固溶处理时,组织中铁索体组织与奥氏体组织的比例接近1:1,钢的综合力学性能最佳。 相似文献
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根据冶金热力学的计算结果,提出了钢液-气相界面可能发生的NH3和[O]、[S]耦合反应.该界面反应过程促使NH3在钢液界面生成易被钢液吸收的活性氮原子,同时,脱除了钢液中的氧、硫杂质元素,与常压下钢液吹氮增氮的工艺比较,可以取消为增氮而采用的钢液预脱氧、脱硫工艺环节,减少钢中非金属夹杂物的生成.10 kg中频感应炉的冶炼实验结果表明,合金成分相同的钢液供给等摩尔氮含量的氮化介质,NH3比N2的增氮效果提高了18%~75%.吹NH3条件下,钢液中保持一定量的氧、硫表面活性元素,有利于氮的吸收. 相似文献
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介绍了宝钢电炉流程在生产低氮钢方面采取的主要技术措施。包括电炉提高铁水比、造泡沫渣、终点碳控制、EBT;LF气氛控制、造好白渣、埋弧操作;VD提高脱氮率,钢液成分对脱氮的影响;连铸钢包长水口及氩封防止钢液吸氮。 相似文献