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通过提高奥氏体中铌等微合金元素的固溶量来提高非再结晶区温度,对X80管线钢进行高温控制轧制,进一步细化晶粒,在提高钢材强度的同时明显改善钢材的韧性。 相似文献
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《钢铁钒钛》2020,(4)
为了明晰X80管线钢凝固过程中析出物粒子析出规律。采用Thermo-calc软件对X80管线钢凝固过程中奥氏体、铁素体相转变温度,析出物类型,析出物开始析出温度与析出相最大质量分数进行热力学分析。计算结果表明:X80管线钢凝固过程析出相主要包括MnS相、AlN相、铁素体相及奥氏体相、富钛相碳氮析出相、富铌相碳氮析出相与碳化钒析出相。富钛相碳氮析出相析出温度为1 390℃,质量分数为1.2×10~(-4),析出相随C元素和Nb元素的含量增加而受到抑制。N元素和Ti元素含量增加会促进富钛相碳氮析出相生成,V元素质量分数增量对富钛相碳氮化物无明显规律。富铌相碳氮析出相在1 110℃析出,质量分数为1.3×10~(-3),随C元素和Nb元素的含量增加,促进富铌相碳氮析出相析出。增加N元素与Ti元素含量抑制富铌相碳氮析出相析出,V元素对富铌相碳氮化物无明显影响规律。碳化钒析出相析出温度为596℃,析出相质量分数为4.59×10~(-5),增加C元素和V元素含量利于碳化钒相析出,Nb元素含量增加对碳化钒相起到一定抑制作用。 相似文献
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微合金化钢的碳氮化物在奥氏体中的行为 总被引:3,自引:0,他引:3
本文对微合金化钢中微合金化元素钒、铌、钛的碳氮化物在奥氏体中的行为进行了综合评述。着重论述和分析了这些碳氮化物在奥氏体中的成份特征,溶解和析出规律,对奥氏体再结晶和晶粒长大的抑制效应,以及这些行为对钢后续转变,后续析出和最终性能的影响。结合理论分析,还介绍了有关规律在实际生产中的应用和前景。 相似文献
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在Gleeble热模拟试验机上,研究含铌微合金钢中铌的析出物在形变诱导相变过程中的作用机理,结果表明:当加热温度为1000℃时,部分铌的碳化物未溶解于奥氏体中,而加热温度为1100℃时,铌的碳化物能够全部溶解到奥氏体中,含铌微合金钢加热温度范围约在1000~1100℃之间。铌的未溶解碳化物和在冷却过程中析出的碳化物都能作为铁素体形核位置,从而促进γ→α相变的发生。 相似文献
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氧化物冶金是将非金属夹杂物变害为利,它是利用钢中高熔点粒子改善钢的组织,进而改善钢板焊接热影响区(HAZ)性能的有效手段。以DH36级船板钢为依托钢种,根据二维错配度理论,系统研究了不同微合金元素铌和钒对船板钢铸态组织中诱发奥氏体晶内针状铁素体(IAF)的影响。研究表明,根据错配度理论,微合金元素钒易于铌诱发IAF,但是当奥氏体向铁素体转变时,微合金元素钒的第二相粒子在钢中析出温度低、析出量少,所以微合金元素铌充分细化了钢的铸态组织、轧态及焊接HAZ组织,HAZ低温冲击韧性约为微合金元素钒的4倍,达到工业化生产大线能量焊接用钢板的要求。 相似文献
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The influence of rare earths on the behavior of precipitation of 14MnNb,X60 and 10Mn V steels was studied by STEM, XRD, ICP and thermal simulation method. The main carbonitride precipitates are Nb(C, N), (Nb, Ti) (C, N) and V(C, N). In austenite RE delays the beginning of precipitation, and decreases the rate of precipitation. In ferrite RE promotes precipitation and increases the amount of equilibrium carbonitride precipitation. RE can make precipitates fine,globular and dispersed in the microalloyed steels. With the increase of the amount of RE in steel, the amount of precipitation increases. The promotion effect is weakened with excessive RE. RE has only little influence on the strength of microalloyed steel, but it can improve impact toughness effectively. 相似文献
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金属矿中稀土和稀散元素的测定对其综合利用具有重要意义。难溶元素Nb、Ta、Zr、Hf采用酸溶法处理时较难溶解完全,Nb、Ta采用碱熔法处理后再用王水浸取存在不稳定的问题。实验采用偏硼酸锂熔融样品,酒石酸体系浸取,解决了上述Nb、Ta等元素测定中遇到的难题。通过选择待测同位素和干扰校正方法在线校正,以10 μg/L185Re和10 μg/L103Rh为混合内标,采用电感耦合等离子体质谱法(ICP-MS)对浸取液进行测定,实现了对金属矿中La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y共15种稀土元素,及Nb、Ta、Zr、Hf、Ga、Rb、Cd、Cs、In、Tl共10种稀散元素的测定。方法校准曲线的线性相关系数均大于0.999 7,方法检出限为0.03~0.85 μg/g,定量限为0.09~2.55 μg/g。将实验方法应用于铅矿石、钨矿石、钽矿石和锆矿石标准物质中稀土和稀散元素的测定,结果的相对误差(RE)为-5.33%~6.67%,相对标准偏差(RSD,n=12)不大于9.8%。采用实验方法对洛宁铅锌多金属矿区的样品进行测定,结果的相对标准偏差(n=5)不大于9.3%。 相似文献
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Thermodynamics of rare earths in steelmaking 总被引:1,自引:0,他引:1
The standard free energies of formation of the oxides, sulfides and oxysulfides of cerium and lanthanum under steelmaking
conditions have been calculated and used to predict the behavior of rare earths in steelmaking. Deoxidation and desulfurization
constants, expressed in terms of Henrian activities, have been used to construct a precipitation diagram which indicates the
sequence of rare earth inclusion formation. An enrichment of lanthanum in (RE)-oxysulfide and cerium in (RE)-sulfide is predicted.
It is also predicted that rare earths should be able to reduce the soluble oxygen and sulfur contents of liquid steel well
below the contents presently found in most industrial and laboratory practices. A simple method of calculating steelmaking
additions for complete rare earth control of inclusion composition is presented.
Formerly a Research Engineer at McMaster University 相似文献
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《中国稀土学报(英文版)》2016,(3)
The effect of rare earths(La, Ce and Pr) addition on residual stress in iron coatings prepared by brush plating was investigated. The results showed that the addition of rare earth transformed the residual stress in the coating from tensile to compressive. To relieve the residual stress, on the one hand, RE elements segregated at the grain boundaries which restricted the coalescence of the grains and provided more capability of grain deformation. On the other hand, RE elements could purify detrimental element and absorb hydrogen atoms in the coating. Among the three rare earths, elements lanthanum showed the most significant effect on surface morphology and residual stress. 相似文献
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Evaluation of Tribological Performance of PTFE Composite Filled with Rare Earths Treated Carbon Fibers under Water-Lubricated Condition 总被引:1,自引:3,他引:1
Carbon fibers (CFs) were surface treated with air-oxidation, rare earths (RE) after air-oxidation, and rare earths, respectively. Erichsen test was conducted to study the interfacial adhesion of PTFE composites filled with carbon fibers treated with different treatment methods. Tribological properties of the PTFE composites, sliding against GCr15 steel under water-lubricated condition, were investigated on a reciprocating ball-on-disk UMT-2MT tribometer. The worn surfaces of the composites were examined using scanning electron microscopy. Experimental results reveal that RE treatment is superior to air oxidation in promoting tribological properties of CF reinforced PTFE (CF/PTFE) composite. The friction and wear properties of PTFE composite filled with RE treated CF are the best of the PTFE composites. RE treatment is more effective than air oxidation to improve the tribological properties of CF/PTFE composite owing to the effective improvement of interfacial adhesion between carbon fibers and PTFE matrix. 相似文献
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Computer simulation of the preparation process loading rare earth(RE)directly from acidic extractant and RE chloride was established using MATLAB software.The mechanism of the extraction reaction was assumed,and then an experiment was conducted to confirm the mechanism and the apparent equilibrium constant of the reaction was determined as well.Owing to the involvement of H+ ion in the reaction between acidic extractant and RE chloride,the computer simulation of the process was more complicated than that of the extraction only between different rare earths.In the present work,MATLAB software was therefore introduced to handle the resolution of the complicated processing equation,and the simulation was performed by varying some key parameters including feed composition and phase ratio,etc.Consequently this work presented a simple method to simulate the H+ ion involved countercurrent extraction process of rare earths and also provided the practical references for the relative process designing. 相似文献
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Cu-30Ni-xRE(x=0-0.213 wt.%) alloy was prepared by adding rare earths(RE) in melted Cu-30Ni alloy using metal mould casting method.The effects of RE on corrosion resistance of the alloy in simulated seawater were investigated using optical microscope,scanning electronic microscope with energy-dispersive spectrometer and electrochemical measurement system.The results showed that the corrosion resistance of Cu-30Ni alloy was greatly improved by adding proper amount of RE,whereas excess addition of RE worsened ... 相似文献
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The influence of rare earths(RE) on solidification behavior of a high speed steel for roll was investigated by using differential scanning calorimetry(DSC) in combination of microstructure analysis.It was found that the sequence of solidification was L→γ,L→γ+MC,L→γ+M2C,L→γ+M6C,respectively.The start temperature and the latent heat liberated by unit mass of L→γ and L→γ+MC increased with increase of RE addition,indicating that RE could trigger the crystallization of the primary γ and the MC carbide more effectively.The promoting effect of RE on the heterogeneous nucleation was believed to be an important cause of this effect.Grain refinement,discontinuous network of eutectic carbides and disperse and finer MC were observed in the samples with RE addition,moreover,RES could act as the heterogeneous nucleus of the MC.RE addition was favorable for stable M6C at the expense of the metastable M2C. 相似文献
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屠海令 《中国稀土学报(英文版)》2004,22(5):571-575
The development of rare earths (RE) applications to semiconductor materials and devices is reviewed. The recent advances in RE doped silicon light emitting diodes (LED) and display materials are described. The various technologies of incorporating RE into semiconductor materials and devices are presented. The RE high dielectric materials, RE silicides and the phase transition of RE materials are also discussed. Finally, the paper describes the prospects of the RE application to semiconductor industry . 相似文献
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Metallurgical and Materials Transactions B - Calcium fluoride doped with certain rare earths (CaF2:RE) can be made photochromic by additive coloration,i.e., by treating CaF2:RE samples in a calcium... 相似文献