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近年来低合金高强度钢的进展 总被引:3,自引:0,他引:3
从洁净钢生产、薄板坯连铸连轧无头轧制、薄带铸轧以及以快速冷却为核心的TMCP工艺等几个方面介绍了HSLA钢生产工艺技术的最新发展,并系统介绍了汽车用钢、船舶及海洋工程用钢、管线钢、建筑结构钢、核电用钢、压力容器用钢、工程机械用钢及集装箱用钢等行业所用的HSLA钢品种开发方面新进展。认为未来HSLA钢将向高强、高性能和低成本方向发展,对HSLA钢的发展有指导作用。 相似文献
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我国内燃机气阀钢系列化发展趋势 总被引:8,自引:1,他引:8
根据我国汽车工业的发展形势预测气阀钢的发展趋势,并阐述气阀钢系列化的重要性,描述了世界各国气阀钢的系列概况,探讨了我国气阀钢系列化发展趋势,包括马氏体气阀钢、奥氏体气阀钢、气阀合金、低俣金进气阀用钢4部分。重点是马氏体和氏体气阀钢的发展。 相似文献
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TRIP钢中合金元素的作用和处理工艺的研究进展 总被引:2,自引:0,他引:2
为了给TRIP钢的试制提供参考,对各种合金元素在TRIP钢中的作用进行了描述,并介绍了热轧和冷轧TRIP钢的处理工艺。认为TRIP钢的研究、生产、应用与双相钢相似,能生产双相钢的生产线即可生产TRIP钢。为生产符合我国国情的TRIP钢,应加强微合金元素钒、钛在TRIP钢中作用的基础研究。 相似文献
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涟钢20t转炉出钢过程钢流温降规律的研究 总被引:3,自引:0,他引:3
统计分析了涟钢20t氧气顶吹转炉的出钢温度,出钢过程钢水温降、出钢过程钢水温降速率等的分布状况,研究了影响出钢过程钢水温降的因素,建立了出钢过程钢水温度变化数学教学,研究结果表明,降低出钢温度,缩短出钢时间、提高钢包内衬温度可显著减少出钢过程钢水温降。 相似文献
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采用非线性方程计算法计算20CrMnTiH钢末端淬透性,只需利用生产实际数据加以修正,就能进行精确的淬透性计算和预报,与实测值偏差不超过2HRC。采用化学成分设计和控制,保证20CrMnTiH钢△[C]不超过0.007%,△[Si]波动不超过0.04%,△[Mn]、△[Cr]不超过0.02%,△[Ti]不超过0.01%,△[Alt]不超过0.010%,[Ni]、[Cu]不超过0.05%,[Mo]、[W]、[V]不超过0.03%,[P]、[S]不超过0.020%,[N]和[B]分别不超过0.006 0%和0.0005%,并控制碳偏析指数不超过1.035%,可实现国际先进水平的末端淬透性HRC4带宽控制。 相似文献
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针对HP295钢,采用热力学计算预测了冶炼和凝固过程中夹杂物的组成,同时,用扫描电镜(SEM)及能谱仪(EDS)对夹杂物的形貌和成分进行分析.结果表明:采用硅锰脱氧时,钢液中形成的夹杂物主要为鳞石英(SiO2)、锰铝榴石(3MnO·Al2O3·3SiO2)、莫来石(3Al2O3·2SiO2)和刚玉(A1203)等4类,且随【Al】含量提高或[01含量降低,夹杂物逐渐从鳞石英为主向刚玉为主转变,[A1]〈1×10^-6时主要为鳞石英,a[O]〈3×10^-3时则以刚玉为主;凝固过程析出夹杂物的组成与[Al]、[O]含量有关,1550℃时,当n[O]〉115.6×10^-5及[A1]〈4.5×10^-6时析出鳞石英,当口【O】〈115.6×10^5及[A1]〈10.5×10^-6时析出莫来石,当[A1]〉10.5×10^-6时析出刚玉;1510℃时,当a[01〉75.2×10^-5及[Al]〈3.51×10^-6时析出鳞石英,a[O]〈75.2×10^-5及[A1]〈8.18×10^-6时析出莫来石,[A1]〉8.18×10^-6时析出刚玉;另外,当3钢中有[Ca]存在时,凝固时可能析出钙斜长石甚至假硅灰石,析出物的成分及数量与钙的活度有关.热力学计算预测结果与扫描电镜分析结果基本一致,表明该热力学计算方法是可行的. 相似文献
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对超低氧钢中同时降低[Al]s、[O]的热力学以及实践方法进行了实验研究,并对实验结果和其它文献中结果进行了对比.结果表明,实验钢中T[O]和[Al]含量低而且波动范围窄、相对稳定,明显优于文献中的结果.从热力学角度分析,aAl2O3远小于1,即生成低熔点的易去除的复合夹杂物是同时降低[Al]s、[O]的关键.因此,同时降低[Al]s、[O]是可行的,并且实践中可通过生成低熔点的复合12CaO·7Al2O3夹杂物来达到同时降低[Al]s和[O]的目的.这一研究对解决连铸水口堵塞和提高钢材洁净度有着重要的意义. 相似文献
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A theoretical investigation on the magnetic properties of rare-earth Er3+ in Er3 Ga5 O12 was reported. The average magnetic moments(M) for applied magnetic field H parallel to the [001 ], [ 100], [ 110], [ 111 ] direction was studied based on the quantum theory. Temperature dependence of the magnetic properties is analyzed for H applied parallel to the [ 100] and [ 111 ] crystallographic directions. The magnetization decreases with increasing temperature,showing good agreement with thermal effect. A strong anisotropy of the magnetization is found under high magnetic field, but when the magnetic field is small, M and H are proportional. 相似文献
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基于某钢厂现场条件,对转炉炼钢过程氧化镍直接合金化冶炼耐候钢的可行性进行了热力学分析,结果表明:铁水中固有的[C]、[Si]、[Mn]、[Fe]等均可作为还原NiO的还原剂元素,在铁水阶段和转炉阶段进行直接合金化是完全可行的。在转炉出钢温度T=1960 K,w([C])=0.04%条件下,[C]的还原能力比[Fe]强,镍的回收率可达到99.9%。并在实验室进行了相关的动力学实验研究,1573 K时,在铁水(含碳3%)条件下氧化镍的还原反应速率非常快,15 min后氧化镍还原反应基本完成。 相似文献
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MC MacLeod A Kootstra BK Mansfield TJ Slaga JK Selkirk 《Canadian Metallurgical Quarterly》1980,77(11):6396-6400
Benzo[a]pyrene (B[a]P), 7,8-dihydroxy-7,8-dihydro-B[a]P, and 9,10-dihydro-B[a]P are metabolized by hamster embryo cells to derivatives that bind to nuclear macromolecules. The selectivity for different classes of macromolecules varies depending on the compound analyzed. The ratio of DNA specific activity to protein specific activity (pmol bound/mg of macromolecules) is high (1.51) for 7,8-dihydroxy-7,8-dihydro-B[a]P, extremely low (0.03) for 9,10-dihydroxy-9,10-dihydro-B[a]P, and intermediate (0.26) for B[a]P. Histones H3 and H2A are the major targets of 7,8-dihydroxy-7,8-dihydro-B[a]P; a protein(s) with a mobility similar to that of histone H1 is heavily labeled by 9,10-dihydroxy-9,10-dihydro-B[a]P, with minor labeling of other (nonhistone) bands. The labeling pattern seen with B[a]P is a combination of the patterns seen with the two dihydrodiol metabolites studied. Analysis of the ethyl acetate-soluble metabolites suggests that hamster embryo cells produce 9,10-dihydroxy-7,8-oxy-7,8,9,10-tetrahydro-B[a]P from 9,10-dihydroxy-9,10-dihydro-B[a]P and raise the possibility that this vicinal diol epoxide is an intermediate in the binding of 9,10-dihydroxy-9,10-dihydro-B[a]P to nuclear proteins. The differences seen suggest that factors other than the intrinsic chemical reactivity of the epoxide group are extremely important in the interaction of potential ultimate carcinogens with biological systems. 相似文献
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The protein product of the het-s heterokaryon incompatibility gene of the fungus Podospora anserina behaves as a prion analog 总被引:2,自引:0,他引:2
The het-s locus of Podospora anserina is a heterokaryon incompatibility locus. The coexpression of the antagonistic het-s and het-S alleles triggers a lethal reaction that prevents the formation of viable heterokaryons. Strains that contain the het-s allele can display two different phenotypes, [Het-s] or [Het-s*], according to their reactivity in incompatibility. The detection in these phenotypically distinct strains of a protein expressed from the het-s gene indicates that the difference in reactivity depends on a posttranslational difference between two forms of the polypeptide encoded by the het-s gene. This posttranslational modification does not affect the electrophoretic mobility of the protein in SDS/PAGE. Several results suggest a similarity of behavior between the protein encoded by the het-s gene and prions. The [Het-s] character can propagate in [Het-s*] strains as an infectious agent, producing a [Het-s*] --> [Het-s] transition, independently of protein synthesis. Expression of the [Het-s] character requires a functional het-s gene. The protein present in [Het-s] strains is more resistant to proteinase K than that present in [Het-s*] mycelium. Furthermore, overexpression of the het-s gene increases the frequency of the transition from [Het-s*] to [Het-s]. We propose that this transition is the consequence of a self-propagating conformational modification of the protein mediated by the formation of complexes between the two different forms of the polypeptide. 相似文献
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控制电弧炉[P][S]含量和[Pb][Zn]总量,为生产洁净钢创造了基本条件,防止炉渣回磷和无渣出钢操作是获得低[P][S]电弧炉钢水的关键操作。应控制炉料中[Pb][Zn]含量,当熔清时,[Pb]等成分超出标准要求的情况下,首先停止喷碳操作,增大吹氧强度和角度,将[C]降至0.10%以下,钢水经搅拌和升温,促使沉降在炉底[Pb]通过钢水的溶解、氧化被炉渣捕集,2~6min后,喷入发泡剂碳粉,使Pb氧化物还原成Pb蒸发排出,脱[Pb]率为19.0%~46.4%。脱[Zn]操作与脱[Pb]相同。 相似文献