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稀土、铌对重轨钢铸、轧态组织与性能的影响 总被引:6,自引:2,他引:6
对比研究了BNbRE与U71Mn重轨钢连铸方坯的组织和常规力学性能;通过测量硬度, 揭示了接近共析成分的重轨钢连铸坯结晶组织的变化特征. 采用金相和SEM等手段, 对BNbRE钢和BNb钢热轧轨的轨头、轨腰和轨底角3种部位的组织和夹杂进行了观测, 发现实验钢的铸坯有3个硬度恒值区和3个硬度变化区, U71Mn钢的铸坯里有可观的P共晶组织;未加稀土的BNb钢轨夹杂物, 有轨头和轨底为氧化物和轨腰MnS居多的分布特征等. 文章得出, 加稀土不仅改善和细化了钢的铸、轧态组织, 改变了夹杂物, 还明显地减少了硬度变化结晶区尺寸及其硬度值的变化幅度, 有效地抑制和甚至消除了磷共晶组织. 相似文献
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稀土对60CrMnMo热轧辊钢夹杂物形态的影响 总被引:17,自引:8,他引:17
采用扫描电镜和金相显微镜对不同稀土加入量的60CrMnMo热轧辊钢夹杂物的大小、变形系数和数量进行了研究。实验结果表明:60CrMnMo钢中加入稀土后,大颗粒的夹杂物明显减少;长条状的硫化锰被等轴状的稀土硫化物所代替;当稀土加入量在0.01wt%~0.05wt%时,夹杂物的数量最少;加入量超过0.10wt%后,夹杂物数量略有增加,即稀土加入量过多,反而会增加钢中夹杂物的数量。 相似文献
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钢包加入、残留痕量稀土对U71Mn钢重轨组织和性能的影响 总被引:2,自引:2,他引:2
采用金相、图像分析和测量HRC等方法,对较洁净的U71Mn钢及其在钢包加入0.02%和0.04%RE、残留稀土为0.0022%~0.0025%的U71MnRE钢重轨的组织与性能进行了“profile”实验研究,同时测量了试验钢热轧态及变形态样品的内耗。结果表明:在VD精炼的钢包加入稀土不仅能有效净化钢质,而且残留的痕量稀土能改变钢的夹杂物、细化珠光体、有效减轻和抑制钢组织与性能的不均匀性。U71MnRE钢里高出的0.06%C增加了钢轨的硬度及嵌镶内应力、应变量,因而增大了SKK阻尼和高温过程组尼。 相似文献
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稀土对钢中碳化铌溶解和析出行为的影响 总被引:5,自引:3,他引:5
通过透射电镜,X射线衍射分析,电解相分析及热模热等手段,研究了稀土对控轧含Nb钢析出相-碳化铌的结构,溶解和析出行为的影响,实验结果表明,钢中加入稀土后,碳化铌颗粒变小且弥散分布,在900-950℃碳化铌析出达最高值,随温度升高析出量急骤下降,1200℃时碳化铌基本溶解,在奥氏体化温度下,稀上有抑制碳化铌析出的作用,随稀土量增加其作用愈显著,稀土使碳化铌在奥氏体区析出时间增长,沉淀析出速度降低。 相似文献
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提出了氢化物发生-原子荧光光谱法测定核电用钢中痕量锡的方法。样品在酒石酸溶液存在下,用盐酸-硝酸(3+1)混合酸溶解,用50 g·L-1硫脲-抗坏血酸混合溶液作掩蔽剂,20 g·L-1硼氢化钾溶液作为锡(Ⅳ)的还原剂,氢化反应在pH 5.0~5.5介质中进行,锡的质量浓度在50μg·L-1范围以内与相应的荧光强度呈线性关系,方法的检出限(3s/k)为0.4μg·L-1。应用此方法分析了核电用钢及不锈钢标准样品中锡的含量,并与电感耦合等离子体原子发射光谱法作了比较,测定值与标准值相符,结果的相对标准偏差(n=8)均小于4.5%。 相似文献
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模拟生物膜方法研究钢在海水中的腐蚀行为 总被引:8,自引:0,他引:8
近年来,微生物腐蚀受到广泛重视。本文根据生物膜的结构特征,以含羧酸官能团的β-D甘露糖醛酸单元等构成的天然高分子多糖凝胶沉积于电极表面,形成模拟生物膜,初步建立起模拟生物膜环境的实验方法,并探讨了模拟海水NaCl溶液中生物膜对10CrMoAl、E2低合金钢和18-8不锈钢腐蚀行为的影响。采用极化曲线法、电偶电流测试及交流阴抗谱等电化学方法研究了上述材料在模拟生物膜环境中的腐蚀电化学行为,得到了一些 相似文献
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A spark-source mass spectrometric (SSMS) method capable of determining traces of hydrogen in micro-volumes of metals was developed by using a pointed metal probe technique. The hydrogen background was decreased to μg g?1 levels by the combination of a method in which the sample in the ion source is baked under vacuum at 323–343 K for more than 25 ks and a liquid nitrogen or liquid helium cryogenic pump method. This method was applied to the analysis of austenitic stainless steels at μg g?1 hydrogen levels, and the relative standard deviation was within 20% for samples with hydrogen concentrations ranging from 2 to 4 μg g?1. The relative sensitivity coefficent was 2.3 (Fe=1). 相似文献
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稀土在石油套管钢中的应用研究 总被引:9,自引:2,他引:7
稀土在J-55钢级套管钢中有净化钢液,变质夹杂和微合金化作用,提高了钢的横向冲击值和抗裂纹扩展能力,显著改善了抗射孔开裂性能。稀土变质MnS和Al2O3夹杂的程度,分别取决于钢中稀土与锰和稀土与铝的活度比值,而活度比值决定了钢中REAlO3和RE2O2S的相对数量和性能。 相似文献
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Tanguy Morvan Patrick Ganster Vincent Barnier Krzysztof Wolski 《Surface and interface analysis : SIA》2017,49(7):666-673
An adequate model of quantification when there are many segregating elements is required for industry and research. Hence, for the first time, surface segregation kinetics on industrial 16MND5 steel was studied by XPS spectroscopy at temperatures ranging from 500 to 600 oC. From measurements that highlight the competitive segregation of P, S, Sn, Sb, As, and Cu impurities at the surface, a quantification model was developed and successfully used to deduce the surface concentrations during segregation kinetics as well as derive the corresponding diffusion coefficients. We observed that phosphorus and sulfur are the first elements covering the surface, then they are supplanted by others' impurities. This result may reflect impurities segregation behavior at the grain boundaries that impacts mechanical behavior of the material. Indeed, to further the research, 16MND5 samples were aged in the same range of temperatures. Then, Auger spectroscopy measurements at grain boundaries were conducted on broken samples exhibiting intergranular cracking. Results show that phosphorus is the only segregating element present at grain boundaries after 2 months of aging. Importantly, it appears that phosphorus grain boundary segregation kinetics is significantly lower than at surface. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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模拟地热水中304不锈钢管和镀锌钢管的腐蚀与结垢 总被引:2,自引:0,他引:2
采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学测试的方法研究了304不锈钢管和镀锌钢管在模拟地热水(我国中部平原地热水的环境条件)中的腐蚀与结垢行为.结果表明,不锈钢管的结垢产物为"针"状物,其组成主要为CaCO3和MgCO3;镀锌钢管的腐蚀与结垢产物为"球"状物和"针"状物,其组成主要为Zn(OH)2、ZnO和CaCO3;腐蚀产物与结垢产物在晶核的形成生长过程中往往存在相互作用,同时它们在基材表面的分布对镀锌钢管的进一步腐蚀产生一定的抑制作用. 相似文献
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应用电化学动电位再活化法(EPR法)评价不锈钢复合板和低铬铁素体不锈钢的晶间腐蚀敏感性. 结果表明,以电化学动电位再活化法测得的反向扫描与正向扫描电流最大值之比(ir / ia)评价堆焊不锈钢复合板00Cr17Ni14Mo2/20R复层晶间敏感性与传统H2SO4-CuSO4-Cu法测定的结果吻合甚好;评价爆炸复合板复层06Cr13R低铬铁素体不锈钢晶间腐蚀敏感性与草酸浸蚀法测定的也一致. 说明该法可以成功用于定量、定性地评价不锈钢复合板和低铬铁素体不锈钢的晶间腐蚀敏感性. 相似文献
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分光光度法测定钢电镀层中的铬(Ⅵ) 总被引:1,自引:0,他引:1
薛萍 《广东微量元素科学》2010,17(6):68-70
建立了用弱碱性溶液萃取—二苯卡巴肼分光光度法测定电镀钢中铬的方法。结果表明,在Cr(Ⅵ)质量浓度为0.0~1.0 mg/L的范围内与吸光度线性关系良好,r=0.999 8,加标回收率为97.0%~105.2%,相对标准偏差RSD为3.75%。 相似文献
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The dissolution and precipitation of boron have been studied in a high-carbon steel. Boron was found in different states: boron oxides, boron carbonitrides and iron-borocarbides Fe23(B,C)6. The dissolution of iron-borocarbides in austenite is complete at 1100 °C and precipitation along grain boundaries of this boron-bearing phase was observed after water-quenching from high austenitizing temperature. Therefore, boron precipitates along grain boundaries before pearlite nucleation. 相似文献