Fu-Yuan Dong
,
Peng Zhang
,
Jian-Chao Pang
,
Qi-Qiang Duan
,
Yi-Bin Ren
,
Ke Yang
,
Zhe-Feng Zhang
金属学报(英文版)
doi:10.1007/s40195-016-0370-9
Three high-nitrogen stainless steels with different N contents were successfully processed by equal-channel angular pressing for one pass, and their microstructures and mechanical properties were investigated. It was found that the microstructure of the billet was heterogeneous across the billet thickness, resulting in the difference in the mechanical properties due to the different deformation conditions. A relatively low strength, high uniform elongation, and high work-hardening rate for the samples at the bottom of the billet was achieved in comparison with those processed at the top. Meanwhile, it was observed that the density of deformation twins increased with the content of N; accordingly, the strength and elongation of the alloys increase with the content of N, resulting in a good strength-ductility combination.
关键词:
High-nitrogen
,
stainless
,
(HNS)
,
steels
,
Equal-channel
,
angular
,
pressing
,
(ECAP)
,
N
,
content
,
Twinning
,
Strength
,
Ductility
Jun Luo
,
Hong Yan
,
Nan Zheng
,
Rong-Shi Chen
金属学报(英文版)
doi:10.1007/s40195-016-0378-1
Four kinds of Mg alloys with different Zn and Ca concentration were selected to analyze the effect of Zn and Ca concentration on the microstructure and the mechanical properties of Mg-Zn-Ca alloys. It was found that Zn and Ca concentration has a great influence on the volume fraction, the morphology and the size of second phase. The Mg-1.95Zn-0.75Ca (wt%) alloy with the highest volume fraction, continuous network and largest size of Ca2Mg6Zn3 phase showed the lowest elongation to failure of about 7%, while the Mg-0.73Zn-0.12Ca (wt%) alloy with the lowest volume fraction and smallest size of Ca2Mg6Zn3 phase showed the highest elongation to failure of about 37%. It was suggested that uniform elongations of the Mg-Zn-Ca alloys were sensitive to the volume fraction of the Ca2Mg6Zn3 phases, especially the network Ca2Mg6Zn3 phases; post-uniform elongations were dependent on the size of the Ca2Mg6Zn3 phase, especially the size of network Ca2Mg6Zn3 phase. Reduction in Zn and Ca concentration was an effective way to improve the room-temperature ductility of weak textured Mg-Zn-Ca alloys.
关键词:
Mg-Zn-Ca
,
alloys
,
Ductility
,
Hot
,
rolling
,
Texture
,
Second
,
phase
Cui-Hong Li
,
Qi-Qiang Duan
,
Zhe-Feng Zhang
金属学报(英文版)
doi:10.1007/s40195-016-0371-8
A new parameter, i.e., tearing toughness, was employed to characterize the mechanical properties of some ductile metals (Cu, Cu-2 wt% Be, Cu-Al alloys, and some steels) by using three-leg trousers tearing tests. The experimental results demonstrate that their tearing toughness is not a physical constant and shows a close relationship with the materials’ types and microstructures. It can be inferred that the tearing toughness of different ductile metals has their respective variation range, expectantly, and may be represented by the comprehensive mechanical properties of strength and ductility for various ductile materials.
关键词:
Ductile
,
metals
,
Strength
,
Ductility
,
Tearing
,
toughness
姚赞
,
张忠铧
上海金属
桥梁缆索钢丝通过高碳索氏体盘条冷拉拔生产,但镀锌和稳定化处理常导致钢丝扭转值显著降低,无法满足缆索指标要求.主要模拟镀锌和稳定化热处理过程对冷拉钢丝塑性的影响并开展研究,结果显示,在420 ～500℃温度范围内进行27s短时间热处理对钢丝塑性影响不明显,随460℃保温时间的延长钢丝扭转值先缓慢上升,后迅速降低,由27 s时的35次下降到72s的13次,钢丝塑性显著降低.保温初期扭转值缓慢上升主要与钢丝拉拔应力释放有关,进一步延长保温时间钢丝硬度不断提高,塑性降低,导致钢丝扭转值显著降低,继续增加保温时间将导致钢丝纤维状组织的渗碳体片层发生球化,硬度下降.
关键词:
热处理
,
高强度
,
冷拉拔
,
镀锌钢丝
,
塑性
