莱钢应用氮化钒铁生产高强度螺纹钢筋的生产实践

本文介绍了莱钢应用氮化钒铁生产英标460级高强度螺纹钢筋的生产实践,验证了采用钒、氮微合金化工艺是提高钢筋强度,改善钢筋综合性能的一条经济、有效的途径。     

国内外氮化钒铁及氮化钒制备情况简介

为推动含钒氮低合金钢的发展 ,在查阅主要文献的基础上 ,重点介绍了氮化钒铁及氮化钒制备的工艺方法、条件及产品情况。     

三级钢筋钒合金化的实践与研究

承钢冶炼三级钢试验了钒铁、氮化钒和氮化钒铁3种不同的钒合金,钢筋性能均满足用户要求。通过对比分析其成分控制,认为对于钒吸收率,氮化钒铁最高、氮化钒次之、钒铁最低。对比其钢筋性能,在碳当量相同时,认为加氮化钒的钢筋其屈服强度和抗拉强度最高,氮化钒铁次之,钒铁最低,对低成本冶炼三级钢具有指导意义。     

氮化钒合金在400MPa级钢筋中的应用

介绍了攀钢采用氮化钒合金化与钒铁合金化生产400MPa级含钒钢筋(20MnSiVⅢ级钢筋)的对比试验结果,研究了钒、氮微合金化对钢筋的性能和组织的影响,探讨了氮化钒的强化机理,比较了使用两种合金的生产成本。     

"钒铁+富氮剂"微合金化HRB400钢筋生产试验

介绍利用“钒铁＋富氮剂”微合金化工艺生产HRB400热轧螺纹钢筋的工业试验。实践表明，这一微合金化工艺生产的产品能够满足国家标准的要求，并降低了成本，扩大了利润空间。     

攀钢氮化钒技术的发展及市场前景

介绍了国内外氮化钒的生产技术及攀钢在研究制取氮化钒技术方面的进展,同时对氮化钒产品的市场前景作了预测。     

钒微合金化在生产高强度抗震钢筋方面的冶金优势

分析了抗震钢筋的各种关键性能,对抗震钢筋的主要生产工艺、退火和自回火(QST)工艺以及微合金化(MA)工艺的优缺点进行了评述。研究结果表明,钒微合金化工艺能够使钢筋的各种性能达到最优组合,满足所有的基本性能指标。同时还能减少重要的加工过程中所存在的问题,降低钢铁生产企业在浇注和轧制过程中的劳动强度。     

钒微合金化高强抗震钢筋HRB500E的生产实践

为扩大品种,推进建筑钢筋的升级换代,满足市场对抗震钢筋的需求,广钢利用钒微合金化技术,成功开发了HRB500E钢筋混凝土用热轧带肋钢筋。开发的含钒HRB500E钢筋抗震性能好,产品实物质量优于GB1499.2-2007标准要求。     

钒氮微合金化钢筋的研究

研究了在２０ＭｎＳｉ钢中添加高氮钒合金Ｎｉｔｒｏｖａｎ１２对钢的力学性能的影响。结果表明,在钒含量相同的情况下,与８０ＦｅＶ相比,添加Ｎｉｔｒｏｖａｎ１２的钢,抗张强度可提高１３５ＭＰａ,屈服强度可提高１１７．５ＭＰａ;在保持强度相同或相近的情况下,添加Ｎｉｔｒｏｖａｎ１２的钢可节约３３．３％以上的钒。钢中添加Ｎｉｔｒｏｖａｎ１２合金,充分利用了廉价的氮元素,促进了Ｖ（Ｃ,Ｎ）的析出,南昌市了Ｖ的     

Self-propagating high-temperature synthesis of ferrovanadium nitride for use in smelting high-strength low-alloy steels

A new alloying material for smelting high-strength low-alloy steel is considered: FERVANIT fused ferrovanadium nitride. Self-propagating high-temperature synthesis in the ferrovanadium-nitrogen system permits the development of a new industrial production technology for alloys based on vanadium nitride. Self-propagating high-temperature synthesis requires no electrical energy, is environmentally benign, and results in a product with good operational properties.     

承钢钒铁炉底吹N2水模型试验研究

通过建立1：2的比例的水力学模型,对承德钢铁集团有限公司钒铁车间2t的钒铁炉底吹N₂进行了水力学模拟实验,同时利用正交分析,主要考察了不同的吹气孔位置、吹气流量对铁水混匀时间以及熔池流态的影响.结果表明：不同的底吹气孔组合以及气体流量的控制,会对熔池的混匀产生很大的影响.对实验数据采取正交分析,可以发现当吹气孔位置为e-b-d,吹气流量为1092 L·min^-1时,气体对熔池的搅拌能力是最强的,此时铁水混匀所需时间最短,且流场分布合理.     

Effect of oxygen on hydrogen cracking in high-strength weld metal

The effect of oxygen content on the susceptibility of high-strength weld metal to hydrogen cracking is examined. Increasing oxygen content had a detrimental effect on the cracking susceptibility of weld metal containing a dψusible hydrogen content of 4.7 ppm. In weld metal containing a much lower dψusible hydrogen content (0.87 ppm), increasing weld metal oxygen content had no detrimental effect on hydrogen cracking susceptibility. These results are explained by a model which proposes that hydrogen cracking occurs when a critical oxide inclusion density promotes intergranular fracture at prior austenite grain boundaries and when a critical level of hydrogen is present in the weld metal. For the same level of hydrogen (moisture) contamination, high-strength weld metals containing oxygen contents greater than 200 ppm will be much more susceptible to hydrogen cracking than deposits made using inert gas-shielded or vacuum-operated welding processes. Formerly Visiting Scientist, Department of Metallurgy and Materials Science, University of Toronto     

Effect of oxygen on hydrogen cracking in high-strength weld metal

The effect of oxygen content on the susceptibility of high-strength weld metal to hydrogen cracking is examined. Increasing oxygen content had a detrimental effect on the cracking susceptibility of weld metal containing a dψusible hydrogen content of 4.7 ppm. In weld metal containing a much lower dψusible hydrogen content (0.87 ppm), increasing weld metal oxygen content had no detrimental effect on hydrogen cracking susceptibility. These results are explained by a model which proposes that hydrogen cracking occurs when a critical oxide inclusion density promotes intergranular fracture at prior austenite grain boundaries and when a critical level of hydrogen is present in the weld metal. For the same level of hydrogen (moisture) contamination, high-strength weld metals containing oxygen contents greater than 200 ppm will be much more susceptible to hydrogen cracking than deposits made using inert gas-shielded or vacuum-operated welding processes. Formerly Visiting Scientist, Department of Metallurgy and Materials Science, University of Toronto     

采用CaO-Mg复合脱硫剂进行铁水脱硫的工业试验

近10年来,随着科学技术的进步、工业的迅速发展,市场对钢材的质量(特别是钢中含硫量的限制)愈来愈严格。为了获得优质低硫铁水,提高钢材质量,为了改善高炉和炼钢炉生产的技术经济指标,铁水炉外脱硫已成     

Extinction of persistence in a within-subject partial reinforcement experiment.

Male albino Wistar rats (N = 96) served as Ss in 2 within-S partial reinforcement experiments, designed to lessen generalization in acquisition as a means of eliminating the generalized partial reinforcement effect in extinction. When the use of a separate-phase mode of training alone proved to be unsuccessful for this purpose, a phase of extinction was interpolated between the continuously and partially reinforced acquisition phases. This manipulation was successful and Ss receiving the training sequence of partial reinforcement-extinction followed by continuous reinforcement-extinction did not show the generalized partial reinforcement effect in the final extinction phase. It is suggested that during the phase of interpolated extinction avoidance responses were counterconditioned to the stimulus complex which included nonreward. (French summary) (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)