有效晶粒尺寸对具有超细晶铁素体／渗碳体组织的低碳钢韧脆转变温度的影响

通过研究超细晶铁素体／渗碳体钢的良好韧性，人们发现钢的有效晶粒尺寸(dEFF)对其钢韧脆转变温度(DBTT)有着重要的影响，并且这一概念还可以应用于研究显微组织为：超细晶铁素体／渗碳体(Uf-F／C)、铁素体／珠光体(F／P)的钢中，对于经过淬火(Q)、淬火-回火(QT)的等低碳钢也适用。对于(Uf-F／C)，F／P，Q和QT钢有效晶粒尺寸分别为8、20、100和25μm，     

Nb-V-Ti微合金钢中奥氏体两相区变形过程组织演变

利用循环加热-淬火工艺制备超细晶奥氏体的基础上,将超细晶奥氏体快冷至两相区实施不同应变速率下的单道次变形,分析其在两相区的动态组织演变特征。结果表明：奥氏体晶粒尺寸为1～3μm的Nb-V-Ti微合金,在两相区不同应变速率变形下可获得尺寸小于500 nm铁素体晶粒,且变形过程中铁素体由初始的不均匀条带状分布逐渐演变为均匀弥散化分布。     

变形速率对普碳钢中形变诱导铁素体相变的影响

针对普通碳素钢(Q235类型),研究在Ae3～Ar3温度区间内采用形变诱导铁素体机制获得超细晶铁素体的数量与变形速率的相互关系。实验在Gleeble 1500热模拟实验机上进行。实验方案为：1000℃保温2min,以10℃／s的速度冷却到变形温度[Ae3(840℃)至Ar3(780℃)],变形量为30％～50％,变形后立即水淬。结果表明,在840℃变形时,随着变形速率的增大,形变诱导铁素体量增多;在780℃变形时,随着变形速率的增大,形变诱导铁素体量减少;而在840-780℃之间变形时,变形速率存在最佳值,在该值下诱导生成的铁素体量最大。     

45钢等径弯曲通道变形及组织细化研究

研究了等径弯曲通道(ECAP)变形后45钢中先共析铁素体及珠光体组织的演变特征.结果表明,ECAP变形4道次后,片层状的珠光体组织演变成了超细的渗碳体颗粒均匀分布于亚微晶铁素体基体的组织.先共析铁素体由原始的平均晶粒尺寸约为30 μm演变为大角度晶界分离的、平均晶粒尺寸约为0.4μm的超细晶组织.ECAP变形后,先共析铁素体首先在其内部会形成具有薄片层界面(LBs)的板条位错胞甚至亚晶组织.进一步变形时位错胞或亚晶可继续细化.再进一步变形时通过晶界滑移和晶粒旋转的方式可以获得具有大角度晶界分离的、等轴的超细晶组织.     

微量元素和变形条件对超细晶中厚板显微组织的影响

通过对3种不同铌、钒含量的低碳钢进行多道次热压缩变形以模拟中厚板的超细晶轧制工艺，考察了显微组织演变过程、微合金元素和变形条件对组织演变的影响。结果表明：变形过程中有部分奥氏体通过形变诱导相变转变为铁素体；变形并快速冷却后得到平均晶粒尺寸为3～6μm的超细晶组织．铌促进、钒抑制形变诱导铁素体相变，铌、钒微合金化均有较好的细化作用，铌的作用优于钒．再结晶温度以上进行的粗轧有利于精轧时形变诱导铁素体的形成；在精轧温度范围内，增加变形道次、降低道次应变率有利于获得细化的显微组织；降低终轧变形温度对组织细化是最有效的．     

超细晶粒钢技术的实验室试验研究

利用Gleeble-2000热模拟试验机和实验室中φ150mm的两辊小型试验轧机对Q235钢进行了低温热模拟变形试验，从机理上分析了获得超细晶粒组织的工艺参数的要求，试验获得了晶粒尺寸小于5μm的超细晶粒组织。     

低碳钢先共析铁素体和形变诱导铁素体的相变机制、组织和性能

通过Gleeble 1500热模拟机对Q235钢加热至950℃ 5 min;1℃/s冷至855℃ 30 s,以应变速率15 s^-1,进行80%压缩,淬火,获得形变诱导铁素体组织,并用950℃ 5 min,炉冷获得先共析铁素体组织。试验结果表明,形变诱导铁素体晶粒尺寸≤5μm,平均HV229.55,抗拉强度809 MPa;先共析铁素体晶粒尺寸10～20μm,晶粒不均匀,平均HV210.28,抗拉强度736 MPa。文中分析了形变诱导铁素体和先共析铁素体相变热力学和动力学机制。     

超细晶粒钢的强韧性研究

研究了工业生产的超细晶粒热轧钢板的强韧性。结果表明：用Q235普碳钢成分生产的超细晶粒热轧钢板的显微组织为铁素体和珠光体,铁素体晶粒尺寸为3～5μm,抗拉强度和屈服强度分别达到510MPa和400MPa以上,超细晶粒热轧钢板不仅具有较高的强度,而且具有较高的延伸率和韧性。     

普通碳锰钢的超细晶板材控轧工艺研究

在GLEEBLE2000热模拟试验机上进行普通碳锰钢Q345两相区变形实验。研究变形工艺条件对材料微观组织的影响．分析其组织演变规律及机理，并且在实验轧机上进行板材轧制实验。结果表明，实验钢（0．16C，0．3Si，1．29Mn）采用在过冷奥氏体区及其邻近的两相区变形可以获得等轴超细晶铁索体组织；控轧获得的9mm板材铁索体晶粒细化到晶粒截距4μm．抗拉强度580MPa，伸长率29％。     

普通低碳钢奥氏体晶粒细化及其对变形强化相变铁素体晶粒尺寸的影响

研究了普通低碳钢奥氏体昌粒的细化及其对形变强化铁素体晶粒尺寸的影响。结果表明：通过在奥氏体区进行低温（850℃）较大变形，奥氏体晶粒尺寸可细化至约10μm。奥氏体晶粒尺寸对形变相变后的铁素体晶粒尺寸产生影响。奥氏体晶粒细小，则铁素体晶粒细小且均匀。但其影响随着变形温度的降低而逐渐减弱。     

Acceleration of Electricity Reform Brings Benefit to Big Electricity Users,Aluminum Manufacturers Can Save Costs Up to Several Hundred Million

<正>Recently the National Commission of Development and Reform again assembled experts to solicit opinions,and discussed new electricity reform program.According to information disclosed by experts attending the meeting,in the future electricity reform will undergo top-down design,possibly a     

Qinghai's Aluminum Processing Capacity to Rise at the End of the Year

正Since the release of Implementation Opinions on Carrying out‘Guiding Opinions of the State Council on Resolving Serious Production Overcapacity Conflicts’,according to the actual situation of industry,Qinghai has focused on electrolytic aluminum,cement,ironsteel(including iron alloy and silicon carbide),     

Recent Trends in China's Copper Scrap Market-Part Ⅱ

<正>2.Tianjin Scrap Metal Market In Tianjin,we mainly visited Jinghai Ziy Town scrap market and Binhai New Area’some copper scrap enterprises and enterprise using copper scrap.In Ziya we felt the coppe scrap market was particularly deserted,mos copper scrap enterprises in the town wer closed,industry insiders said in 2012 the plac here was bustling with activity.According to     

Shanghai Clearing House to Roll out Renminbi-denominated Copper Clearing Operations in Free Trade Zone

正Clearing House Financial Markets Co.,Ltd.(Shanghai Clearing House)General Manager Xie Zhong told the media recently at the briefing of the international symposium of"Reform Deepening and Mechanism Innovation of the Post-crisis Kerb Market",Shanghai Clearing House will explore the feasibility of carrying out bond business in     

Development and Application of New Materials for Copper Processing in China

正After over 60 years of developmnt,a system for RD and production of copper processing materials has already taken shape in China.After the reform and opening-up,the application of copper processing materials has gradually expanded from the military industry to civil field.The annual output of copper     

China’s Mineral Exploration Market Downturn Causes Decline of Investment in Bauxite

<正>According to a survey report conducted recently by China Geological Survey Development Research Center,in the first half of 2014,China’s mineral exploration market continued to decline,with the investment in exploration of non-fuel minerals dropping by13.7%and drilling workload dropping by21.7%.According to statistical analysis of the Center,     

Fabricated Copper Production by Province or City in 2014

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Zinc Production by Province in 2014

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China's Aluminum Alloy Cable Market has Taken Shape

正Aluminum alloy cable is a mature product and technology that has been used for nearly fifty years in the U.S.Through six years’promotion,it has been widely recognized and accepted in the China market since 2013,which laid the foundation for the development of the aluminum alloy cable market.Aluminum alloy cable is widely applied in the fields of civil construction and industrial and mining enterprises,especially in real estate,steel and metallurgy.     

Qinghai to Build a 100 Billion Yuan Lithium Industry Base

正At 2014 China Qinghai Trade Fair for Green Development Investment,Qinghai EV Rally2014 was introduced for the first time.With electrical vehicles’eco-friendly features,Qinghai manifested its determination on green development.Introducing Qinghai EV Rally was just a signal.By leveraging its rich salt lake resources