Yuanbin ZHANG
,
Dengyi REN
材料科学技术（英文）
Carbides in a series of cold-welding weld metals were studied by means of SEM, TEM and EPMA, and the forming mechanism of carbide was proposed according to their distribution and morphology. Due to their different carbide-forming tendency, Nb and Ti could combine with C to form particulate carbide in liquid weld metal and depleted the carbon content in matrix, while V induced the carbide precipitated along grain boundary. But too much Nb or Ti alone resulted in coarse carbide and poor strengthened matrix. When suitable amount of Nb, Ti and V coexisted in weld metal, both uniformly distributed particulate carbide and well strengthened matrix could be achieved. It was proposed that the carbide nucleated on the oxide which dispersed in liquid weld metal, and then grew into multi-layer complex carbide particles by epitaxial growth. At different sites, carbide particles may present as different morphologies.
关键词:
Cold-welding
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刘志伟
,
赵宝纯
,
郭晓宏
,
刘凤莲
,
乔磊
,
杨玉
上海金属
介绍了屈服强度700 MPa级集装箱用高强钢的成分设计思路和主要的轧制工艺参数,并分析了产品的性能、组织和析出相.试制结果表明:通卷钢板的力学性能均匀,组织由位错密度很高的块状铁素体和少量贝氏体组成,析出相主要为不同形态的铌、钛的碳氮化物,在铁素体中析出的细小的TiC第二相粒子沉淀强化作用更大.
关键词:
集装箱
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700 MPa级高强钢
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热轧卷板
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析出相
Feng WANG
,
Yuansheng JIN
,
Dunyuan HU
,
Jishan ZHANG
材料科学技术（英文）
Spray deposition is a novel process which is used to manufacture rapidly solidified bulk and near-net-shape preforms. In this study, Al-20Si-5Fe-3Mn-3Cu-1Mg alloy was synthesized by spray deposition technique. The aging process of the alloy was investigated by differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM). The results show that two kinds of phases, i.e. S(Al2CuMg) and sigma(Al5Cu6Mg2), precipitate from matrix and improve the tensile strength of the alloy efficiently at both the ambient and elevated temperatures (300℃). In addition, the sigma-Al5Cu6Mg2 is a relatively stable phase which improves microstructural stability of the alloy.
关键词:
Spray deposition
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