共查询到18条相似文献,搜索用时 78 毫秒
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超高强度马氏体时效钢的发展 总被引:11,自引:3,他引:11
马氏体时效钢是以无碳(或超低碳)铁镍马氏体为基体的经时效生产金属间化合物沉淀硬化的超高强度钢。该钢在高强度时效处理前具有良好的成形性,时效处理几乎不变形,时效处理后有高强韧性。文中论述了典型Ni-Co-Mo-Ti-Al马氏体时效钢和Ni-Mo-Ti(-Cr-Al)无钴马氏体时效钢的化学成分和力学性能,阐述了马氏体时效钢在400~500℃时效时马氏体基体内产生大量强化效果极高、韧性损失极小的金属间化合物沉淀相的时效结构和强化机制,以及Ni、Co、Mo、Cr、Mn、Ti等元素在马氏体时效钢中的合金化作用。概述了马氏体时效钢的生产工艺,应用和发展趋向。 相似文献
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马氏体时效钢是依靠马氏体强化和经时效在马氏体内析出金属间化合物的第二相强化而获得超高强度的钢。本文研究了15Ni马氏体时效工具钢的化学成分、经816℃×2h油冷的固溶处理以及480℃×2h时效处理后的显微组织和热处理硬度。对15Ni马氏体时效工具钢的合金化特点进行了初步的分析讨论。 相似文献
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Yi He Ph.D. Ke Yang Kai Liu Ph.D. Wei Sha Zhanli Guo 《Metallurgical and Materials Transactions A》2006,37(4):1107-1116
The age hardening kinetics in the temperature range of 713 to 813 K of a 2400 MPa grade cobalt-free maraging steel (Fe-(18.8
∼ 19.1) pct Ni-(4.4 ∼ 5.4) pct Mo-2.6 pct Ti, wt pct) has been studied. Study of microstructure and mechanical properties
showed that a high number of Ni3Ti and Fe2(Mo,Ti) precipitates were formed during the ageing process, which resulted in high strength and relatively low fracture toughness.
Ni3Ti was the main precipitation phase. Fractography has shown ductile failure of tensile and fracture toughness specimens. Thermodynamic
calculations showed that the equilibrium phases are Ni3Ti, Fe2(Mo,Ti), ferrite, and austenite. 相似文献
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研究了不同的热处理工艺后18Ni(300)马氏体时效铜棒的晶粒度水平,以及在满足技术标准条件下的拉伸性能与晶粒度的关系,找到了获得满足技术标准要求的晶粒度与拉伸性能的18Ni(300)Zh氏体时效钢棒(规格:直径φ≤100mm)的最佳热处理工艺。 相似文献
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针对我国钴资源稀缺及传统WC–Co硬质合金在腐蚀介质与高温环境下应用所存在的缺陷,总结了一系列性能良好的少钴/无钴WC材料,包括以其他金属或金属间化合物替代Co作为粘结剂的WC硬质合金,不添加任何粘结剂的纯WC材料以及由陶瓷相增强的WC复合材料,讨论了少钴/无钴WC材料的优缺点,并展望了其发展趋势。 相似文献
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T250马氏体时效钢晶粒尺寸对时效析出的影响 总被引:1,自引:0,他引:1
在840 ℃ 1 h固溶退火+480 ℃ 4 h时效处理条件下,不同晶粒度的T250马氏体时效钢力学性能比较试验表明,材料的性能和晶粒尺寸关系并不表现出明显的依存关系。相应的XRD和显微结构比较研究显示,马氏体时效钢的时效行为和晶粒尺寸相关。晶粒细小的马氏体钢时效时形成更多体积分数的逆转奥氏体,以膜状分布在晶界和亚晶界起到软化作用而有利于材料塑韧性的提高;同时产生更为细小弥散的沉淀相起到更为明显的强化作用。这可能是材料的力学性能和晶粒尺寸关系不明显的组织结构原因。 相似文献
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Reju Mathew Reji Manu Mohan U. Harikrishnan Vinu Thomas Joseph K. Sreekumar Tony Varghese 《Transactions of the Indian Institute of Metals》2015,68(1):35-40
The present work deals with the ultra-high strength maraging steels, which are exotic materials used for high tech applications in aerospace and nuclear fields. Masking of a fabrication defect in a critical component by filling it with cheap mildsteel weldment to avoid rejection on visual inspection may lead to catastrophic failure when put into service. This paper is aimed to simulate formation of such a defect in a maraging steel rod and to analyse the probable metallurgical reasons leading to its premature failure using optical and scanning electron microscopy and energy dispersive spectroscopy. 相似文献
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《Baosteel Technical Research》2011,5(4):3-7
The 18Ni 300 grade cobalt-free maraging steel T300 was successfully manufactured on an industrial scale by application of vacuum induction melting (VIM) and vacuum arc remelting (VAR) process at Baosteel.With the content of O and N less than 15 ppm and 10 ppm respectively (1 ppm=10-6),the T300 steel produced by Baosteel obtained a high degree of purity and a good combination of ultra-high strength and fracture toughness.The effects of solution temperature and ageing temperature on tensile property of solution-treated and aged T300 steel were investigated.The results show that the solution temperature slightly influences the strength of the solution-treated steel,indicating that the solution strengthening rather than the grain boundary strengthening is more important to the solution-treated steel.For the solution-treated T300,the elongation and reduction of area don’t change much with a rising solution temperature,and remain above 17% and 70% respectively at the solution temperature ranging from 800℃ to 1200℃.For the aged T300 steel,the strength and elongation are reduced with an increasing solution temperature,and the solution temperature has a greater effect on the reduction of area than that on the elongation.The reduction of area of the aged steel reaches a high peak when the solution temperature reaches 920℃.The experimental data indicates that precipitation strengthening makes a contribution of 1100 MPa to the tensile strength of the aged steel.The ageing temperature exerts a greater effect on the strength than on the elongation and reduction of area.The steel achieves a better combination of strength and toughness at the peak ageing temperature of 500℃. 相似文献
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Fatigue crack growth rates were measured in an annealed and in an aged maraging steel and in three different austenitic steels.
Microhardness measurements were used to determine the plane strain plastic zone sizes as a function of ΔK and to evaluate
the cyclic flow stress of the material near the crack tip. The presence of a reversed cyclic plastic zone within the monotonic
plastic zone was confirmed. The two maraging steels work soften near the tip of the crack while the three austenitic steels
work harden. The fatigue crack growth rates of the maraging steels are independent of the monotonic yield stress and are typical
of the growth rates of steels with a bcc crystal structure. The crack growth rates in the stainless steels are an order of
magnitude lower than for maraging steels for ΔK< 30 ksi √in. The excellent fatigue crack growth resistance of austenitic stainless steels is related to the de-formation induced
phase transformations taking place in the plastic zone and to the low stacking fault energy of the alloys. 相似文献