XING Shu-qing
,
CHEN Zheng-zong
,
MA Yong-lin
,
LI Hui-qin
钢铁研究学报(英文版)
The effect of refined precipitations and dispersed phases on the toughness of SS400 steel was investigated by rapid tempering with thermomechanical simulation tester, and the electromagnetic induction rapid tempering process was simulated. The conventional tempering and rapid tempering process were proceeded respectively, and both samples were quenched in 10% of agitated iced brine. The tempering temperatures were designed as 560, 620 and 680 ℃, respectively. Rapid tempering specimens were heated at a heating rate of 20 ℃/s, and all samples of these three tempering temperatures were maintained 30, 40 and 50 s with the Gleeble1500-D tester, respectively. The impact test at -40 ℃ were carried out on a Charpy impact machine (CBD-300) with a maximum measurement range of 300 J and the microstructures were analyzed in detail using optical microscope (OM) and scanning electron microscope (SEM). The experiment results show that the upper bainite, martensite and small amount of austenite were obtained in the rapidly quenched samples. In comparison to the conventional process, the matrix microstructure was changed from the larger size and bulk ferrite to the refined banding structure, and the cementites were obviously refined and precipitated inside the grains and along the grain boundaries. The cryogenic impact test implies that the maximum values of impact toughness with holding time of 30 or 50 s are achieved at tempering temperature of 620 ℃. Furthermore, a favorite value of impact toughness with holding time of 40 s is available.
关键词:
SS400 steel
,
rapid tempering process
,
thermomechanical simulation tester
,
precipitation
,
cryogenic impact toughness
张鸿冰
,
倪乐民
,
徐祖耀
金属学报
经 LFG(ΔG~(γ→a))-Mogutnov(ΔG_(Fe)~(γ→a))、徐祖耀(Shu-A)(ΔG~(γ→a))-Orr-Chipman(ΔG_(Fe)~(γ→a))、徐祖耀(Shu-B)(ΔG~(γ→a))-Orr-Chipman(ΔG_(Fe)~(γ→a))组合,均可算得 Fe-Mn-C 合金的 Ms 温度且与实验值十分符合.所得结果经数学处理,得 Fe-Mn-C 系 Ms 与成分的关系为:Ms(K)=817.4-7513.4xc-4141.9x_(Mn)-32083.5x_Cx_(Mn)(LFG)Ms(K)=829.9-7580.5x_C-4166.0x_(Mn)-15727.8x_Cx_(Mn)(SHU-A)Ms(K)=829.2-7276.1x_C-2915.4x_(Mn)-43825.7x_Cx_(Mn)(SHU-B)其线性相关系数均大于0.992.C 和 Mn 浓度均使合金的 Ms 线性地降低,而碳的作用几乎是Mn 的两倍.处理中引入了合金元素交互作用项(x_Cx_(Mn)),表明 C,Mn 相互加剧对 Ms 的影响。随含 C,Mn 量的增加,相变驱动力均单调地增加,而不存在奇异点.Ms 和相变驱动力的计算值均依赖于ΔG_(Fe)~(γ→a)项.
关键词:
Journal of Materials Processing Technology
The crystallization temperatures and other thermal properties have been measured systematically for two ternary Cu-Ni-P and two quaternary Cu-Ni-Sn-P amorphous systems. The dependence of crystallization temperature on the composition for the four alloy systems can not be described basically by the usual used Naka rule. The Gibbs free energy of crystallization can be calculated for the alloy systems with the model proposed by Shu et al. Using the calculated free energy of crystallization, it is still not possible to properly describe all of the crystallization temperatures of the alloy systems. However, it has been found that the correlation between the crystallization temperature and the content of the alloy systems can be reasonably explained by the nucleation and growth rates of a new phase for the classical theory of phase transformation. It has been established that the classical theory of phase transformation can be used to describe the thermal stability of the Cu-based amorphous alloys during their crystallization process. (C) 1999 Published by Elsevier Science S.A. All rights reserved.
关键词:
thermal stability;amorphous alloys;Cu-P based alloy systems;classical;theory of phase transformation;solid-liquid interface;structural model;glasses
盖红星
,
李建军
,
韩军
,
邢艳辉
,
邓军
,
俞波
,
沈光地
,
陈建新
量子电子学报
doi:10.3969/j.issn.1007-5461.2005.01.016
采用Shu Lien Chuang方法计算了AlInGaAs/AlGaAs应变引起价带中重、轻空穴能量变化曲线,在Harrison模型的基础上详细地计算了AlInGaAs/AlGaAs和GaAs/AlGaAs量子阱电子、空穴子能级分布并且进一步研究了这两种材料在不同注入条件下的线性光增益.进一步计算比较可以得出AlInGaAs/AlGaAs应变量子阱光增益特性要优于GaAs/AlGaAs非应变量子阱增益特性,因此AlInGaAs/AlGaAs应变量子阱半导体材料应用于半导体激光器比传统GaAs/AlGaAs材料更具优势.
关键词:
光电子学
,
应变量子阱
,
光增益
,
AlInGaAs
,
半导体激光器
