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排序方式: 共有532条查询结果,搜索用时 15 毫秒
51.
Ling Zhang Wangyue Yang Weiwei Zheng Zuqing Sun 《北京科技大学学报(英文版)》2005,12(6):517-520
The carbides/nitrides precipitates in ferrite grains, on grain boundaries and dislocations were investigated on a hot-rolled C-Mn strip (0.16wt%C-1.22wt%Mn-0.022wt%Ti) produced by the CSP (compact strip production) technology using TEM and X-ray energy dispersive spectroscopy. The Pickering's equation for the contribution of precipitates to the yield stress was also discussed. It is shown that there are numerous fine and dispersive precipitates TiC in the ferrite grains, on the grain boundaries and dislocations. Also there are a small amount of coarser Ti(C, N) particles and TiC particles associated with MnS. Precipitation strengthening on steels produced by the CSP technology is significant. 相似文献
52.
Three indicators (T1000, T5000, and T1000/T5000) are used to appraise the infrared (IR) transmission spectra for Cd1−xZnxTe (CZT) slices. By comparing the values of these three indicators, four typical types of IR spectra are characterized for
CZT crystals. The CZT crystals possessing the four types of IR spectra are different in microstructures, especially the densities
and sizes of Te precipitates, the free carrier concentrations, and the resistivities. Mechanisms for the elimination of tiny
and dense Te precipitates are given by analyzing the variation of the IR transmittance in the range of 500–5000 cm−1 during the annealing process. 相似文献
53.
Byung-Hak Choe Soo-Keun Shin Sung-Joon Kim Yong-Tai Lee S. B. Kang Masuo Hagiwara 《Metals and Materials International》2005,11(6):429-433
The effects of aging treatment on the microstructures and mechanical properties of a metastable beta titanium alloy Ti-15-3
(Ti−15V−3Al−3Sn-3Cr) have been investigated with hardness measurements, tensile test, and optical and electron microscopy.
Precipitate-free beta structure with average grain size of about 56 μm was obtained after solution treatment at 800°C for
15 min followed by air cooling. Solution treated specimens were aged up to 800 h in the temperature range between 350 and
600°C. The morphology of the precipitates was varied significantly, depending on the aging temperature. The fine aggregates
of α precipitates were dominant above 450°C. Peak hardness values were maintained up to 800 h at 500°C, which showed the superior
thermal stability of α precipitates. Tensile strength increased up to 1600 MPa along with the decrease of elongation after
aging at 350 and 400°C. 相似文献
54.
随着矿井深度的增加,对锚杆支护强韧性的要求越来越高,为了应对这一情况,需要研发出更高强度的锚杆钢。利用锚杆钢研究了轧制工艺、冷却工艺与珠光体、铁素体相比例,析出相析出行为及力学性能的关系。研究结果表明,在中轧后、精轧前采用适当水冷+回复段处理的复合工艺可使晶粒更细小、组织更均匀。对超高强度锚杆钢进行热压缩变形试验,由热模拟试验结果确定相转变温度为Ac1=737 ℃、Ac3=886 ℃。最终筛选出入精轧温度为810 ℃、回复段温度为800 ℃时,可获得的晶粒尺寸达4 μm,珠光体体积分数为66.8%,铁素体体积分数为33.2%,珠光体片层间距达200 nm;另外调整V、Cr、N等析出以提高锚杆钢的强韧性,较低的回复温度有利于细小、弥散、V(C/N)析出相的析出,V(C/N)的析出可进一步改善锚杆钢的力学性能。由该控轧控冷工艺轧制的锚杆钢屈服强度为780 MPa、抗拉强度为930 MPa、硬度为291HV、伸长率为20%。 相似文献
55.
高强度不锈钢因其优异的综合性能及成熟的生产工艺,已成为航空、航天、海洋、石化工程等高端制造业领域的重要材料。系统回溯高强度不锈钢的发展及应用历程,总结此类钢的强韧化机理及最新研究进展,并详细梳理了影响该钢的氢陷阱行为及氢脆抗力的主要因素。结合现有研究成果,提出了采用多种类纳米级第二相颗粒复合析出强化突破高强度不锈钢强韧性匹配极限的思路;通过调控钢中析出相及逆转变奥氏体的交互析出行为,提高后者的机械、化学稳定性,使其作为钢中裂纹及可扩散氢的双重“陷阱”,从而提高钢的裂纹及氢脆抗力。最后指出未来新型高强度不锈钢的研发须重点关注以材料基因算法、人工神经网络、机器学习为代表的“人工智能化”合金设计理念。 相似文献
56.
57.
58.
Weldalite 050, a high-strength Al-Mg-Li alloy, was evaluated for its corrosion resistance in deaerated and air saturated Arabian
Gulf water to determine its suitability for marine applications. Weight loss and electrochemical studies showed that the alloy
had minimum corrosion rates of 1.82 and 4.82 mpy (mils per year), respectively, in deaerated and air saturated Arabian Gulf
water with very high total dissolved solids (TDS) content. Weldalite 050 exhibited good resistance to corrosion at velocities
up to 3.9 m/s. The formation of Al2MgLi, Al-Li, Al12Mg17, and Al-Li precipitates has a pronounced effect on its corrosion resistance. The corrosion resistance of Weldalite 050 compares
favorably with that of alloys 5052 and 5054, wrought alloys 6061 and 6013, and silicon carbide (SiC) reinforced alloys 6061
and 6013. 相似文献
59.
Guiqing Wang Qingzhou Sun Li Shan Zhongkui Zhao Liu Yan 《Journal of Materials Engineering and Performance》2007,16(6):752-756
Effect of indium addition on aging precipitation behavior of 357 cast alloy has been investigated by hardness measurement,
differential scanning calorimetry (DSC) and TEM analysis. Age hardening results show that 0.1 wt.% indium addition to 357
cast alloy increases the peak hardness by 20 HV during aging at 160 °C. DSC and TEM analysis results show that indium addition
constrains precipitation of GP zones, and enhances precipitation of phases. The possible indium atoms participating in the precipitation during aging and the large indium-vacancy binding energy
can explain the effect of indium on aging behavior of 357 cast alloy. 相似文献
60.