钒对高强钢轨钢可焊性的影响

通过焊接热模拟试验,研究了不同钒含量对高强钢轨钢可焊性的影响。结果表明,中０．０８％左右的钒对钢轨钢焊接热影响区的组织、性能没有不利的影响。     

高强度稀土轨的生产

铁路运输的发展需要高强度钢轨,高碳钢轨钢中添加稀土、铌、钒、铬等微量合金元素可较大幅度提高钢轨的强度及耐唐性.本文简要概述了高强度钢轨的发展,介绍了包钢开发研制BNbRE、BNb、BVRE、BV等钢种的试生产情况,并探讨了高强度钢轨的发展趋势.     

采用不同脱氧制度的重轨钢中夹杂物的岩相鉴定

对不同脱氧制度的重轨钢轧成钢轨的试样进行了岩相、金相、化学、扫描电镜、能谱等检验,观察夹杂物的光学特征。检验证明,采用硅钙钒合金脱氧,能显著改变钢轨中非金属央杂物的组成、形态与分布,防止长度大于2 mm 链状的Al_2O_3夹杂的生成,从而提高了钢的强度,可延长钢轨使用寿命25～30%,节约了原材料,降低了成本,提高了经济效益。     

我国重轨钢冶炼技术的发展

随着高速铁路技术的发展,用户对钢轨钢的质量、性能和纯净度提出了更高的要求,而钢轨钢的成分控制和纯净度水平是由其冶炼技术所决定的.本文对我国钢轨钢的生产情况及重轨钢的冶炼技术做了综合论述.     

钒在冷轧带钢中的应用

钒作为微合金元素已广泛应用于热轧低合金高强钢中,人们也对钒在热轧产品中的作用做了大量的基础研究。对冷轧板中钒的作用的研究结果表明钒的析出物在冷轧板热处理过程中会粗化,降低析出强化在钢中的作用,这使得钒并未在冷轧板带钢中得到广泛应用。针对此情况,综述了钒在烘烤硬化钢、冷轧低合金高强钢(包括冷轧双相钢、TRIP钢、TWIP钢等)中的研究现状及进展,发现了钒在冷轧板带钢中的有益作用。     

攀钢重轨钢生产工艺的完善

为满足用户对钢轨内部质量日益提高的要求,攀钢对钢轨钢的生产工艺技术进行了优化,通过铁水预脱硫、钢液脱氧、精炼及浇注工艺技术的系统研究和应用,攀钢重轨实物质量大幅提高,钢轨内部质量指标达到了200km/h钢轨标准要求。     

钢轨钢微合金化及合金轨

介绍了微合金化元素对钢轨钢组织和力学性能的影响，国外生产的部分合金轨的成分和性能，超高强度钢轨的研制现状及合金元素对钢轨钢断裂韧性的影响。     

钒渣直接合金化的研究

本文介绍了电炉炼钢用钒渣合金化及平炉炼钢用钒渣球合金化的工艺。两种工艺钒的回收率分别为90％和75％,试验结果证明,钒渣直接合金化工艺对钢质量无影响。采用钒渣直接合金化冶炼含钒为0.1％的钢,可使钢成本降低约20元/t钢左右。     

高硅铜砱钒钢轨试验阶段报告

高硅铜砖钒钢轨的综合性能良好,抗拉强度(σ_b)约108～112公斤/毫米~2,轨头踏基体硬度约301～321HB,塑性和疲劳性能较好,冲击韧性满足使用要求。试验钢轨铺设在曲率半径为190米,坡度为24～27‰的小半径、大坡度地段。使用七年四个月,通过运量4300万吨后,钢轨耐磨耐压耐冲击性能良好;轨端未淬火使用,接头良好。耐磨性能较普通碳素钢轨提高1～2倍,且具有一定的耐大气腐蚀性能,是一个有发展前途的耐磨钢轨钢品种。     

钢轨矫直断裂原因分析

根据钢轨矫直断裂的形貌、夹杂物和微观组织的分析以及翻钢机实际工作状态,确定钢轨发生矫直断裂过程为:由于翻钢机上夹持辊打开滞后且较慢,钢轨轨头踏面与翻钢机上夹持辊之间产生了滑动摩擦,造成钢轨踏面局部产生了冷变形组织,严重部位产生高温并快速冷却,形成冷形变硬化组织,在后续矫直过程产生裂纹,并造成钢轨断裂。通过清理翻钢机设备状态,优化翻钢工艺,消除了由该原因造成的钢轨矫直断裂现象。     

Э90AΦ steel rail

At OAO Novokuznetskii Metallurgicheskii Kombinat, R65K rail is produced from э90AΦ steel with an elevated carbon content and microadditions of vanadium and nitrogen, so as to increase the wear resistance. Such rail is characterized by satisfactory quality in terms of nonmetallic inclusions, macrostructure and microstructure, mechanical properties, hardness, pile-driver strength, and residual stress.     

120 t转炉半钢增硅热补偿技术研究及应用

针对攀钢钒采用半钢冶炼热源不足带来的终点碳偏低、终渣TFe含量高及捞渣烟尘大的问题,提出在提钒转炉出半钢时加入硅铁对半钢进行化学热补偿的炼钢新工艺,并通过对工艺参数的研究和优化,实现了工业应用。应用效果表明,增硅新工艺减少了转炉兑半钢时碳的烧损以及过程温降,提高了半钢炼钢转炉热源,半钢质量更为稳定,使得中高碳钢终点钢水碳含量在0.07%～0.12%的比例由32.2%大幅度提高到92.38%;重轨钢终渣TFe由19.9%降低到18. 62%,Q系列钢终渣TFe由20. 85%降低到18.89%;且新工艺的应用明显缓解了提钒捞渣烟尘大的问题,具有明显的环保效益。     

Effect of Rare Earths on Properties of BNbRE Rail Steel

The development and properties of BNbRE rail steel and the effect of RE on rail steel were studied. The results show that the properties of rail steel (δb ≥980 MPa, δ5≥ 8 % ) can be improved by adding RE and niobium and adjusting the content of C, Si and Mn in steel. At the same time, the abrasion resistance, contact fatigue and fatigue property of BNbRE rail steel are excellent. It also shows that RE in rail steel has the functions of purifying steel, modifying inclusion and micro-alloy action effect. The improved steel-making process enhances the quality of molten steel. Although the content of RE is low, excellent properties of BNbRE rail steel are achieved.     

Effect of Adding Nitrogen on Microstructure and Property of Vanadium Microalloyed Reinforcing Bar Steel

Worldwideattentionhasbeenpaidtomicroal loyedsteelwhichhasbeendevelopedrapidly .Manyadvantagesofmicroalloyedsteelhavebeenrecog nizeddeeply .Firstly ,themicroalloyedsteelhashighstrengthand goodcomprehensiveproperties .Sec ondly ,highprofitscanbegainedduetolowerpro ductionandapplicationcost .Themicroalloyingele mentsareaddedtomicroalloysteelsforgrainrefin ingandprecipitationstrengthening[1] .　　Theabilityofsecondphaseparticlestomaintainfinegrainsizesathightemperaturebypinningmi gratingboundarie…     

快冷条件下钒对中低氮钢晶粒尺寸的影响

通过实验室轧制试验,研究了中低氮含钒钢在轧后快速冷却条件下的铁素体晶粒尺寸和屈服强度的变化规律.结果表明,加入钒能够细化铁素体晶粒,原因是在快速冷却条件下中低氮含钒钢中的钒全部固溶在基体中,固溶的钒降低铁素体的实际相变温度,从而细化了铁素体晶粒.     

Grain Growth of Deformation Induced Ferrite in V Microalloyed Low Carbon Steel During Controlled Cooling Process

The effect of vanadium on the DIFT (Deformation Induced Ferrite Transformation) microstructure coarsening in low carbon steel during the continuous cooling processes and isothermal processes at different temperatures were investigated using thermo-simulator.The results showed that the steel containing a small amount of vanadium had the similar velocity of grain growth with the vanadium free steel during the continuous cooling process,but a lower velocity of grain growth than that of vanadium free steel during isothermal processes at high temperatures.On the other hand,the vanadium remarkably inhibited grain growth in the steel containing a high amount of vanadium during both the continuous cooling and isothermal processes.Vanadium dissolved in matrix is indicated as an important factor on restraining grain growth through estimating the driving force of normal grain growth and the resistance of precipitation particles of vanadium on grain growth.The influencing mechanism of vanadium dissolved in matrix on the grain growth during the controlled cooling process is discussed.     

Influence of Vanadium on Grain Growth of Deformation Induced Ferrite in Low Carbon Steel during Continuous Cooling Process

The effects of vanadium on the deformation induced ferrite transformation (DIFT) in low carbon steel during heavy deformation at the temperature slightly higher than Ar₃ and on the coarsening of DIFT microstructure during the continuous cooling processes after deformation were investigated using a thermo‐simulator. The results show that vanadium has little effect on the volume fraction of DIFT microstructure under heavy deformation, whereas the deformation induced ferrite (DIF) grains are refined with increasing vanadium content. The steel containing a small amount of vanadium exhibits similar velocity of grain growth compared to vanadium free steel, while the vanadium remarkably inhibits grain growth in a steel containing a high amount of vanadium during the continuous cooling process. The diffusion activation energy of grain boundaries for all the tested steels is calculated and the influencing mechanism of vanadium on the grain growth during the continuous cooling process is discussed.     

Railroad rails made of bainitic steel

Results are presented from a study of the mechanical characteristics and microstructure of rails made at the Novokuznetsk Metallurgical Combine from steel alloyed with manganese, silicon, chromium, molybdenum, and vanadium. It was established that obtaining high strength and hardness in the steel by increasing its contents of carbon and alloying elements has an adverse effect on the service properties of rails made of steels with a bainitic structure. Normalizing is the most effective means of increasing strength and improving microstructure. The required level of mechanical characteristics can be obtained by tempering the steel at 350–370°C. The adverse effect of cold straightening-which is manifest in a reduction in the rails’s impact toughness-can be offset by subjecting the steel to preliminary tempering or normalizing and tempering. Rather than further increasing the strength of rail steel to improve its overall quality, this objective is better served by making sure that the steel is cleanly made, that the rails have little or no curvature, and that the residual stresses in the steel are favorably distributed. __________ Translated from Metallurg, No. 4, pp. 51–53, April, 2007.     

Delayed Fracture Behavior of CrMo Type High Strength Steel Containing Vanadium

The quenchedandtemperedlowalloysteelswithtensilestrengthexceeding 12 0 0MPaaresus ceptibletohydrogen induceddelayedfracture(HIDF )wheninuse[1,2 ] .Despitetheenormousamountofresearchworkperformedondelayedfrac tureofhighstrengthsteelintheseyears ,thesolu tiontothisproblemstillhasnotbeenobtained .TheresistanceofanalloytoHIDFisstronglyaffectedbytheinteractionofhydrogenwithmicrostructuralhet erogeneitiesthatactashydrogentraps ,andthere foreinasearlyas 1980s ,GMPressouyre[3 ] suggest edtheappli…