High-carbon wire rod made of high-chromium steel

A comprehensive study of the quality of experimental wire rod made of steel C82D2 with 0.30% chromium has shown that this material can be used as a replacement for vanadium-bearing wire rod. In this case, it is necessary to subject the rod to two-stage cooling on a Stelmor line in a process that includes the following: • coil formation at t_co = 940–970°C; for 12.0-mm-diam. wire rod, t_co = 960–1000°C; • the operation of six jet-cooling blocks operating with a motor speed of 1480 min₋₁; • transport of the metal on a roller converyor moving at a speed of 0.5 m/sec. The presence of martensitic sections and a cementite (carbide) network in the structure of the metal is not grounds for rejection of the product. __________ Translated from Metallurg, No. 4, pp. 59–62, April, 2006.     

方坯连铸机浇铸高碳钢

方坯连铸机浇铸的高碳钢坯，其深加工产品是机械性能要求较高的钢丝绳、预应力钢丝、轮胎钢丝及弹簧铜丝等．钢中脆性、大颗粒夹杂物是工艺过程的脱氧产物；高碳钢铸坯凝固过程中产生严重的中心偏析和中心疏松缺陷．这些夹杂物和缺陷使得钢丝在冷拔过程中或在使用过程中出现非疲劳断丝．避免质量事故的方法是：控制高碳钢钢水的质量，将炼钢脱氧过程产生Al2O3脆性氧化物夹杂，通过控制渣系使生成的MnO2—Al2O3—SiO2系三元夹杂分布在低熔点区；必须实现无氧化保护浇注；中间包内腔优化对夹杂物上浮效果显著；保证工艺过程操作的最小温度降低；采用连铸坯轻压下技术或高强度高密度冷却技术、结晶器电磁搅拌和控制冷却强度．     

High-deformability wire rod made of steel Sv-08G2S

Welding wire is made with the use of wire rod composed of steels Sv-08G2S, Sv-08G1S, and SG-1, 2, 3. A new technology that has been developed to obtain this product provides for mechanical scale removal, dry drawing of the wire rod to an intermediate diameter of 1.7–2.2 mm, then — without an intermediate heat treatment — wet drying combined with electrochemical copper-plating of the wire surface. The diameter of the wire is 1.6—0.8 (0.6) mm. The advantages of the new technology for making welding wire are obvious: a reduction in production cost due to the elimination of pickling and heat treatment for the rod; an improvement in the environmental situation at the manufacturing plant. __________ Translated from Metallurg, No. 2, pp. 64–70, February, 2007.     

硬线钢用盘条中夹杂物的调查

通过采用扫描电镜对国内外4个钢厂硬线钢用盘条中的非金属氧化物夹杂的类型、形貌、尺寸和数量以及成分分析可知,国内外各厂家的钢帘线盘条中夹杂物的类型主要是CaO- SiO2- Al2O3- MgO- MnO,国外厂家较国内厂家盘条中非金属夹杂物的Al2O3质量分数低,SiO2质量分数高。且国外两厂中的夹杂物变形性能好,呈长条状,长宽比都大于3。应尽量减少单位面积的非金属夹杂物数量和尺寸,如先进的国外甲、乙两厂夹杂物数量的控制水平为0.111~0.154个/mm2,尺寸较小的夹杂物（小于3μm）的夹杂物数量相对国内厂家偏少。国外厂家的wT［O］和wN都控制在0.0035%以内。国外厂家控制水平相对较高,wT［O］和wN分别为0.0021%左右和0.0025%左右。     

软线用钢盘条的生产实践

根据水城钢铁集团有限责任公司炼钢厂工艺装备水平及标准ASTM/A510M的要求,制定了1006和1008软线钢成分控制要求及冶炼、连铸工艺,并成功生产,产品质量满足用户要求.     

钒微合金钢粗晶热影响区的组织和韧性

 利用Gleeble-3800模拟焊接粗晶热影响区（CGHAZ）经历的热循环过程。比较了热输入100 kJ/cm条件下,V钢、V-N钢、V-Ti钢和V-N-Ti钢CGHAZ的组织和韧性,并分析了析出相情况。结果表明,CGHAZ的韧性从高到低依次为V-N-Ti钢、V-Ti钢、V-N钢和V钢;在V钢成分基础上添加钛可以有效细化原始奥氏体晶粒尺寸;V-Ti钢成分基础上增氮,一方面促进了（Ti,V）（C,N）/TiN的析出,抑制了原始奥氏体晶粒的粗化;另一方面促进了V（C,N）的析出,其促进了多边形铁素体的形成;多边形铁素体数量的增加能够减弱自由氮对韧性的破坏,同时有效改善了CGHAZ韧性。     

Production of ultra-high strength wire rod steels by vanadium microalloying

Ultra-high strength high-carbon wire rod steels have been produced using vanadium-microalloying technique instead of the conventional expensive and environment polluting lead patenting treatment. The strength increment attained in the hot rolled steels due to vanadium additions is maintained in the cold drawn wire. By using this technique, high tensile strength levels of 1550-1600 N/mm² were attained either by cold drawing of 0.17% V microalloyed high-carbon steel to 45-47% reduction or by cold drawing of 0.20% V microalloyed high-carbon steel to 25-30% reduction. An equation has been developed to predict the tensile strength from the chemical composition, cooling rate and reduction of area due to cold drawing. A combination of vanadium microalloying and accelerated cooling resulted in additional strength increment due to refining of microstructure and increasing the precipitation strengthening component. Inspite of the decrease in the amount of vanadium precipitates due to the increase in cooling rate, it is suggested that an increase in precipitation strengthening due to refining of these precipitates by accelerated cooling more than offsets the loss of precipitation strengthening due to decreasing the precipitates fraction.     

不锈钢热轧带钢和盘条的生产

通过不锈钢热轧盘条和带钢的试制 ,为公司开发不锈钢、合金钢系列产品积累经验     

钒微合金化低碳钢高温变形动态再结晶

利用热模拟压缩试验测定了不同钒含量的钒微合金化低碳钢在900～1000℃温度区间和0.1～1s-1变形速率范围内的真应力-真应变曲线.对曲线的分析表明:随钢中钒含量的增加,低碳钢的动态再结晶开始时间延长,变形奥氏体的动态再结晶名义激活能提高.实验钢薄膜试样的TEM观察表明,钢中的微量钒以固溶态存在于奥氏体中,微量的固溶钒对奥氏体动态再结晶起到抑制作用.     

Thermomechanical processing of microalloyed powder forged steels and a cast vanadium steel

The effects of controlled rolling on transformation behavior of two powder forged (P/F) microalloyed vanadium steels and a cast microalloyed vanadium steel were investigated. Rolling was carried out in the austenitic range below the recrystallization temperature. Equiaxed grain structures were produced in specimens subjected to different reductions and different cooling rates. The ferrite grain size decreased with increasing deformation and cooling rate. Ferrite nucleated on second phase particles, deformation bands, and on elongated prior austenite grain boundaries; consequently a high fractional ferrite refinement was achieved. Deformation raised the ferrite transformation start temperature while the time to transformation from the roll finish temperature decreased. Cooling rates in the cast steel were higher than in P/F steels for all four cooling media used, and the transformation start temperatures of cast steels were lower than that of P/F steel. Intragranular ferrite nucleation, which played a vital role in grain refinement, increased with cooling rate. Fully bainitic microstructures were formed at higher cooling rates in the cast steel. In the P/F steels inclusions and incompletely closed pores served as sites for ferrite nucleation, often forming a ‘secondary’ ferrite. The rolling schedule reduced the size of large pores and particle surface inclusions and removed interconnected porosity in the P/F steels. Formerly Postgraduate Researcher in the Department of Metallurgy and Materials Science, UMIST/University of Manchester, United Kingdom     

含铌铁水直接冶炼含铌微合金钢的试验

 含铌铁水通过脱碳保铌探索作为合金化元素回收铁水中铌并直接冶炼为含铌微合金钢的方法。试验在真空碳管炉内进行,铁水温度为1 500 ℃,氧化剂为Fe2O3,真空度为10 Pa,分别进行有SiO2-CaO-Al2O3系造渣剂、无渣真空氧化冶炼研究。结果表明：在无渣条件下,加入Fe2O3铁水中硅、铌和碳同时氧化,不能脱碳保铌;加入造渣剂时,造渣剂的碱度越低,铁水中的硅氧化量越低,碳氧化量越高,碳质量分数最低下降到0.032%,铌质量分数最低值从0.09%下降到0.082%;碱度越高,铁水中硅氧化量越高,铌的氧化量也越高;真空氧化冶炼能够促进碳氧化,减少硅的氧化,抑止铌氧化。在50 kg级真空感应电炉内成功进行了回收铁水中铌直接冶炼为含铌钢试验,为回收含铌铁水中的铌提供新方法,也为工业化直接冶炼含铌钢提供试验依据。     

宣钢高强度棒线材车间简介

介绍了宣钢高强度棒线材车间的工艺、设备情况及主要技术参数。重点介绍了其工艺和设备特点,即采用了蓄热式步进梁加热炉,短应力线轧机,V形顶交布置的线材精轧机组,轧钢生产线控制轧制及控制冷却技术等。     

增氮对钒微合金钢组织和性能的影响

 通过对不同钒、氮质量分数的试验钢进行热模拟压缩试验和实验室轧制试验,用OM、SEM和TEM分析试验钢的显微组织,研究增氮对钒微合金钢组织和性能的影响。结果表明,普通钒微合金钢为板条贝氏体＋粒状贝氏体组织,增加氮质量分数,可促进晶内铁素体相变,得到针状铁素体组织,使M/A组织细化且弥散分布,改善韧性;而增加钒质量分数,可以增加析出强化作用,提高强度,但组织形态无明显变化,不能提高韧性。增氮钢中的钒在奥氏体内以VN析出,低氮钢内的钒在铁素体内以VC的形式析出,奥氏体-铁素体、VC-铁素体和VN-铁素体的平面点阵错配度分别为6.72%、3.89% 和 1.55%,在奥氏体内析出的VN可以作为铁素体的优先形核位置,促进晶内铁素体相变。     

弹簧钢盘条脱碳质量改善生产实践

脱碳是评价弹簧钢性能的重要指标之一,表面脱碳会直接影响弹簧成品的疲劳寿命.结合宝钢特钢长材有限公司线材装备特点,针对55SiCr弹簧钢的生产进行脱碳性能优化改进试验.研究表明,通过降低钢坯在炉时间、增加钢坯表面涂层,可有效避免线材表面全脱碳的产生,实现高端冷卷簧产品在宝钢特钢长材有限公司的批量稳定生产.     

高碳钢盘条SWRH82BCr试制

为了满足出口用户的要求,进行了高碳钢盘条SWRH82BCr的生产试制。介绍了该盘条的试制过程,对采用200mm×200mm连铸坯直接轧制的盘条实物质量进行了检验,给出了试制结果。针对首次试制的盘条中心网状碳化物级别、中心马氏体级别偏高的问题,进行了斯太尔摩风机风量的调整,稳定了盘条的出厂性能。试制结果表明:该钢种试制工艺路线合理,优化后的高线斯太尔摩控冷工艺得到固化,盘条的中心网状碳化物、中心马氏体级别均不大于0.77级,索氏体体积分数不小于90%,断面收缩率不小于42.5%。     

高碳70钢热轧盘条的开发与研究

介绍高碳70钢线材盘条在韶钢高线厂的试轧制情况,通过对产品的性能的检验及使用过程中出现问题的跟踪,分析了70钢的试生产结果,对生产工艺进行了优化．