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The microstructure and mechanical properties of prolonged and lower temperature aged Fe–Ni–Mn–Mo–Ti–Cr maraging steel 下载免费PDF全文
A. V. Barenji 《Materialwissenschaft und Werkstofftechnik》2015,46(11):1105-1109
In this study, the microstructure and mechanical properties of Fe–Ni–Mn–Mo–Ti–Cr maraging steel at low temperature and prolonged aging condition were investigated. Optical and scanning electron microscopy examinations, tensile and hardness tests were conducted to study the microstructure, aging behavior and mechanical properties of the cold‐rolled steel. The results showed that aging of cold rolled Fe–Ni–Mn–Mo–Ti–Cr maraging steel resulted in the formation of Mo rich and Ti rich Lave phase precipitates. Existence of many dislocation cores due to cold rolling and subsequently, low temperature aging caused to formation of uniform distribution of very fine precipitates. The presence of these precipitates increased the yield and ultimate tensile strengths but couldn't improve the uniform tensile ductility. This alloy showed ultra‐high fracture stress of about 1950 MPa with a negligible tensile elongation (about 2 %) at the peak aged condition. The fractographic studies indicated this alloy shows semi‐brittle fracture in the subsequent aging treatment. 相似文献
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Effect of Solute Drag and Precipitate Pinning on Austenite Grain Growth in Ti-Nb Microalloyed Steels
《钢铁研究学报(英文版)》2011,(Z1):383-387
A metallurgical model concerning the co-effect of the Nb solute drag and the complex carbonitride precipitates pinning is proposed to predict the recrystallization austenite grain growth of low carbon Nb-containing microalloyed steels.The analysis,both predicted and experimental,reveals the precipitate pinning plays a dominate role in suppressing the austenite grain growth with less Nb solute drag effect in high temperature region whereas the Nb solute drag predominates in relatively low temperature region.A factor p is suggested to assess the effectiveness of drag and pinning.The pinning and the drag are more effective in restraining grain growth as p>0 and p<0,respectively.A low carbon Nb microalloyed steel and a kind of Ti-modified low carbon Nb steel by Ti substituting for part of Nb are employed to validate the modeling results.The theoretical calculations show a good agreement with experimental results. 相似文献
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Modern material and process design aim at cost reduction and property improvement simultaneously. As for carburized engineering components the carburisation is a time consuming process, the idea is to shorten the carburising time by increasing the carburising temperature. To avoid any deterioration in steel properties, the ambition is to hinder austenite grain growth by microalloying case hardening steels. Until now, the results revealed in the literature mainly rely on experimental investigations. However, a recent tendency is to model such processes tied to rigorous numerical approaches. In this paper, modelling of the carburising process of microalloyed steels is presented. The simulation focuses on the formation of carbon profiles in heat treated work pieces considering the influence of precipitates. 相似文献
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以高、中、低3种铌含量的S31042耐热钢作为试验钢,研究了铌含量对S31042钢中析出相及持久性能的影响。结果表明: S31042钢时效处理后,钢中主要含有M23C6相、Z相和MX相;当时效时间达到10 000 h时,钢中发现了σ相的存在。铌含量对S31042钢中析出相的种类和M23C6相的含量影响不大,对含铌相含量的影响显著,随着铌含量的升高,Z相+MX相含量明显增多。700 ℃持久寿命并未随铌含量的升高而单调增加,而在中限铌含量出现最大值,高铌钢中未固溶的粗大一次析出相是造成持久寿命降低的主要原因。 相似文献
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利用OM、SEM、EBSD及TEM等技术研究了卷取温度对51CrV4钢组织和硬度的影响,探讨并分析了不同卷取温度下组织和硬度变化的原因。结果表明,随着卷取温度由600 ℃升高至720 ℃,试验钢的硬度先逐渐降低,690 ℃以上变化不大;先共析铁素体的体积分数由0.33%增大至5.9%,铁素体晶粒尺寸逐渐增大;珠光体平均片层间距由93 nm增大到177 nm。卷取温度由630 ℃升高至720 ℃,(V, Cr)C析出相的平均尺寸由8.3 nm增大至9.7 nm,体积分数由0.247%递减至0.176%。珠光体片层间距是影响试验钢不同卷取温度强度/硬度变化的最主要因素,铁素体晶粒尺寸和纳米(V, Cr)C析出相的影响次之。 相似文献
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王海燕 《稀有金属材料与工程》2017,46(3):735-739
本文采用基于密度泛函理论的第一性原理,计算了Al-La与Al-Y二元合金中金属间化合物的基态特征,在此基础上,研究了稀土La与Y元素在Al中的溶解度,并讨论了稀土铝合金中析出相的力学性能。结果表明,Al-La和Al-Y合金中的最稳定相均为Al2RE金属间化合物。对于含有微量稀土元素的铝合金中的优先析出相,Al3Y(R-3M)较Al3Y(PM-3M)和Al11La3(IMMM)具有更好的稳定性和强化效果。La和Y在Al中的溶解度计算结果显示,与La相比,Y在Al具有较高的溶解度。综合弹性模量和溶解度的结果可知,微量Y可以更加有效的达到强化Al合金基体的效果。 相似文献
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Hui-zhong LI Ze-xiao ZHU Xiao-peng LIANG Peng-wei LI Ye-long QI Feng LV Lan HUANG 《中国有色金属学会会刊》2017,27(12):2539-2547
Transmission electron microscopy (TEM), scanning electron microscopy (SEM), hardness tests and tensile tests were performed to investigate the effect of aging on microstructure and mechanical properties of forged Al-4.4Cu-0.7Mg-0.6Si alloy. The results show that the alloy exhibits splendid mechanical properties with an ultimate tensile strength of 504 MPa and an elongation of 10.1% after aging at 170 °C for 16 h. With tensile testing temperature increasing to 150 °C, the strength of the alloy declines slightly to 483 MPa. Then, the strength drops quickly when temperature reaches over 200 °C. The high strength of the alloy in peak-aged condition is caused by a considerable amount of θ′ and AlMgSiCu (Q) precipitates. The relatively stable mechanical properties tested below 150 °C are mainly ascribed to the stability of θ′ precipitates. The growth of θ′ and Q precipitates and the generation of θ phase lead to a rapid drop of the strength when temperature is over 150 °C. 相似文献