GUO Defu
,
HE Anrui
,
SHAO Jian
,
YANG Quan
,
WANG Zhongming
,
WANG bo
钢铁研究学报(英文版)
CVC mills are generally used in the whole stands of CSP (Compact Strip Product). Their special “s” curve of work roll contour and shifting strategy aimed at controlling strip shape, and the characteristics of continuous casting and rolling production, which make the work roll wear in downstream stands seriously uneven, and easily form abnormal transverse profile at the rolling end. As a result, CVC mill configuration in the downstream stands can not meet the profile and flatness control requirement for schedule free rolling, and bring some difficulties in profile and flatness control for the subsequent cold rolling. Based on the characteristics of the shape control system of CSP production line, and combined with the theory of flat roll technology, a kind of technology solution of using flat roll in the downsteam stands for CSP hot strip mills was proposed. At last, industrial test was carried out in the last stand of Masteel CSP, and good results were obtained.
关键词:
CSP; flat roll; wear; shifting strategy; profile; flatness
万小峰
,
张久兴
,
周文元
,
李湘波
,
周美玲
稀有金属材料与工程
研究了FU105大功率广播发射管用碳化镧钼阴极,参照碳化钍钨阴极FU105管的制备工艺,实现了镧钼阴极的碳化以及镧钼阴极FU105管的排气和老炼.通过镧钼阴极FU105管的性能测试,对碳化镧钼阴极的发射能力和稳定性进行了分析.结果认为:FU105管碳化镧钼阴极的发射能力可以达到碳化钍钨阴极的水平,但其稳定性还有待改进.
关键词:
镧钼阴极
,
FU105发射管
,
碳化
,
稀土
Kehai Li
材料科学技术(英文)
Modification of conventional gas metal arc welding (GMAW) process is of great potential to achieve high productivity with low cost and strong usability. Double-Electrode GMAW (DE-GMAW) is such a modified arc welding process which is formed by adding a bypass torch (gas tungsten arc welding torch) to a conventional GMAW system. The mechanism of metal transfer in DE-GMAW was proposed and verified in this paper. Experiments show that the critical current is decreased so that spray transfer can be obtained at a lower current level in DE-GMAW. Analysis of this significant change in metal transfer phenomena is conducted, and explanation is given out. It is found that the bypass arc in DE-GMAW lifts the anode point on the droplets such that the electromagnetic force becomes larger and squeezes the droplets so that spray transfer can take
place under welding current lower than that in conventional GMAW.
关键词:
Metal transfer
,
null
,
null
钟文远
,
崔永春
,
范春兰
,
胡智兴
,
李玛琳
贵金属
doi:10.3969/j.issn.1004-0676.2004.02.005
为寻求高效低毒的新型顺铂类抗肿瘤药物,用K2PtCl4、乙二胺(en)、氟尿嘧啶(5-Fu)为原料,设计合成了顺铂类似物[pt(en)(5-Fu)2]C12配合物,由元素分析、红外光谱和质谱分析初步证实了其化学结构,用改良MTT、SRB法,选用K562、A549、Bel-7402、BIU-87、Bcap-37细胞株对其进行体外抗肿瘤活性测定.结果表明,所合成的配合物除在浓度为0.01、0.1 μg/mL时对K562细胞株抗肿瘤活性大于顺铂和氟尿嘧啶外,其它情况下的抗肿瘤活性均小于顺铂和氟尿嘧啶.该配合物仍有进一步研究的价值.
关键词:
药学
,
铂(Ⅱ)配合物
,
合成
,
抗肿瘤活性
Materials Letters
Highly preferred (002) orientation transparent conductive Al-doped ZnO (ZAO) films were successfully prepared by de magnetron reactive sputtering from a Zn target mixed with Al of 2.0 wt.%. The film has a resistivity of 4.80 X 10(-4) n cm and a visible transmittance of as high as 90%. XPS analysis indicates Al-enrichment on the film surface. The asymmetry of Al 2p(3/2) XPS peak is resolved into two components: one centering at 72.14 eV attributed to metallic Al and the other having a binding energy of 74.17 eV due to oxidized Al. (C) 2001 Elsevier Science B.V. All rights reserved.
关键词:
Al-doped;ZnO;XPS;Al-enrichment;oxide thin-films;optical-properties;electrical-properties;rf;dc;transparent;deposition
武传松
,
张明贤
,
李克海
,
张裕明
金属学报
doi:10.3321/j.issn:0412-1961.2007.06.021
通过大量的工艺实验,找出了DE-GMAW双焊枪组合的匹配参数,测试了焊接电流波形,拍摄了熔滴过渡图像,并获得了无成型缺陷的焊缝照片.基于实验结果解释了高速焊接工艺的机理.建立了适用于DE-GMAW焊接工艺的有限元模型,并对该工艺条件下的温度场、应力-应变场进行了数值模拟.结果表明:计算出的DE-GMAW焊缝横断面形状尺寸与实验结果吻合良好;在通过焊丝的总电流相同时,DE-GMAW焊接时焊缝尺寸、热影响区宽度、应力、应变及变形均小于常规GMAW焊时的结果.这为DE-GMAW焊接工艺参数优化提供了基础数据.
关键词:
高速电弧焊接
,
工艺机理
,
DE-GMAW
,
有限元分析
ZHANG Xi-liang
,
ZHOU Chang-yu
钢铁研究学报(英文版)
The constant embrittlement curve for constant segregation concentration on grain boundary of impurity element P and relationship between equilibrium grain boundary segregation concentration and operation time for 225Cr-1Mo steel were derived based on the theory of equilibrium grain boundary segregation. The mechanism of step-cooling test and mechanism of de-embrittlement for 225Cr-1Mo steel were explained. The segregation rate will increase but equilibrium grain boundary segregation concentration of impurity element P will decrease as temperature increases in the range of temper embrittlement temperature. There is one critical temperature of embrittlement corresponding to each embrittlement degree. When the further heat treating temperature is higher than critical temperature, the heat treating will become a de-embrittlement process; otherwise, it will be an embrittlement process. The critical temperature of embrittlement will shift to the direction of low temperature as further embrittlement. As a result, some stages of step-cooling test would change into a de-embrittlement process. The grain boundary desegregation function of impurity element P was deduced based on the theory of element diffusion, and the theoretical calculation and experimental results show that the further embrittlement or de-embrittlement mechanism can be interpreted qualitatively and quantitatively by combining the theory of equilibrium grain boundary segregation with constant embrittlement curve.
关键词:
step-cooling test
,
critical embrittlement temperature
,
embrittlement mechanism
,
grain boundary desegregation
武传松
,
张明贤
金属学报
根据当前制造业对高效、优质、低耗焊接技术的迫切要求,研发出低成本的高速电弧焊接新工艺DE-GMAW。该工艺在常规GMAW焊接设备的基础上,通过附加GTAW焊枪构成旁路电弧,分流了一部分通过焊丝的焊接电流,在施加于焊丝的电流较大的情况下(保证了熔敷率),减小了作用于母材的热输入,解决了高速焊接面临的矛盾,实现了高速电弧焊接。建立了适用于DE-GMAW焊接工艺的有限元模型,并对该工艺条件下的温度场和应力变形进行了数值模拟。结果表明:计算出的DE-GMAW焊缝横断面形状尺寸与实验结果吻合良好;在通过焊丝的总电流相同时,DE-GMAW焊接时焊缝尺寸、热影响区宽度、应力、应变及变形均小于常规GMAW焊时的结果。这为DE-GMAW焊接工艺参数优化提供了基础数据。
关键词:
高速电弧焊接
,
process mechanism
,
DE-GMAW
,
finite-element analysis