Mn-Cr系齿轮钢热变形行为研究

采用Gleeble 1500热模拟试验机研究了一种Mn-Cr系齿轮钢的动静态再结晶行为.试验结果表明在给定应变速率1/s下,试验钢存在3种类型的应力-应变曲线变形温度在1 100℃以上时,变形奥氏体发生动态再结晶;1 000～1 050℃之间时只发生动态回复过程;950℃以下时不发生动态再结晶和动态回复.     

15MnMoVTi钢控制轧制研究

研究了15MnMoVTi钢变形的奥氏体再结晶的特征。给出了奥氏体再结晶的临界变形量和再结晶的三个温度区间:温度高于1050℃为动态再结晶区,900～1050℃为静态再结晶区,低于900℃为未再结晶区。再结晶延迟时间达20秒。 15MnMoVTi钢的加热温度在1050～1200℃范围为宜,最佳温度在1150℃左右。轧制总变形量应大于50％,同时应严格控制终轧温度并采用快速冷却措施。影响轧后奥氏体晶粒度的主要因素是终轧温度和轧后冷却速度。     

FH40高强度船板钢再结晶行为研究

研究了变形温度及变形量对FH40高强度船板钢再结晶行为的影响规律。结果表明:试验钢变形量在20%～40%时,形变奥氏体处于部分再结晶区,温度的变化直接影响再结晶数量和晶粒尺寸。FH40高强船板钢发生完全再结晶所需的变形温度为1 000℃、变形量为40%,此条件下变形下进行完全再结晶区轧制,获得细小、均匀的奥氏体晶粒。     

D36船板热变形奥氏体再结晶规律的研究

采用Gleeble 3500热模拟机,研究了D36船板奥氏体的再结晶温度以及奥氏体的变形温度、变形量和变形速率对热变形奥氏体再结晶的影响。结果表明:当变形速率为0.1~1 s-1、温度达到950℃时,开始发生动态再结晶;当变形速率为5 s~(-1)、温度在1 000~1 050℃时,发生动态再结晶;当变形速率为10 s~(-1)时,不发生动态再结晶。当变形温度为1 050℃、单道次变形率在10%~20%时,D36钢在10s左右的道次间隔内发生了完全的静态再结晶。当单道次变形率在20%以上,D36钢在5 s左右的道次间隔内发生了完全的静态再结晶。     

变形温度对ULCB钢动态再结晶的影响

取得800 MPa级和900 MPa级ULCB钢,在1100~850℃进行单道次变形的热模拟试验,变形量为40%,应变速率为2 s-1。将应力-应变变化特征和显微组织观察相结合,分析研究变形温度对ULCB钢奥氏体动态再结晶的影响规律。结果表明,温度低于950℃时以形变硬化和动态回复为主,奥氏体形变再结晶主要发生在1000℃以上的高温变形中;奥氏体再结晶百分数随变形温度升高而增加,在1050℃变形后奥氏体再结晶百分数约40%,在1100℃变形后则发生完全再结晶。     

热变形对40CrMnMo钢的晶粒尺寸影响规律研究

采用了MMS-200热力模拟机以40CrMnMo钢为实验对象进行了热压缩试验,研究了变形温度850℃～1150℃,变形量0.8,应变速率在0.01～10s~(-1)条件下实验钢的热变形行为。通过分析高温下变形参数对流变应力和奥氏体晶粒尺寸的影响,建立40CrMnMo钢的稳态动态再结晶晶粒尺寸模型。结果表明:变形温度为850℃～1150℃,实验钢在应变速率0.01～0.1s~(-1)下发生连续动态再结晶,应变速率1～10s~(-1)下发生动态回复。通过引入Zener-Hollomon(Z)参数表征变形参数对稳态动态再结晶晶粒尺寸的影响,建立了稳态再结晶晶粒尺寸的数学模型,得出提高应变速率或变形温度较低能使Z参数增大,峰值应力升高且动态再结晶晶粒减小。     

SCM435高强冷镦钢热轧过程中的再结晶行为

采用阶梯试样轧制法研究了道次变形量(15%～70%)和温度(850～1150℃)对SCM435钢(%:0.35C、1.05Cr、0.22Mo)变形奥氏体再结晶百分比影响,绘制了该钢的再结晶全图。结果表明,随变形温度提高,奥氏体临界变形量降低。在1150℃45%变形量下,SCM435钢奥氏体可以发生完全再结晶。     

高Nb钢变形奥氏体再结晶规律研究

采用阶梯试样,研究0．09％NbHTP（High Temperalure Processing）钢形变奥氏体再结晶规律,分析变形温度、变形量等工艺参数对变形奥氏体再结晶百分数的影响,绘制实验铜变形奥氏体再结晶图。结果表明,变形量为60％时,实验铜的完全再结晶临界温度为1050℃,未再结晶临界温度为900℃,分别比含Nb0．03％的普通HSLA钢相应温度提高了100℃,热机械加工性能得到大幅度提高,证明高含量Nb对奥氏体再结晶的强烈阻滞作用。     

CSP热轧TRIP钢动态再结晶行为研究

摘要：采用Gleeble-3500热模拟试验机,在温度为950~1150℃、应变速率为0.1~10s-1和变形量为65%的条件下研究了CSP热轧TRIP钢的动态再结晶行为,探讨了初始奥氏体晶粒尺寸对TRIP钢动态再结晶行为的影响。研究结果表明,初始奥氏体晶粒尺寸越小,变形温度越高,应变速率越慢时,TRIP钢中奥氏体越易发生动态再结晶。其中,粗晶试样（初始奥氏体晶粒尺寸为767.54μm）在1050~1150℃内变形时,将发生动态再结晶。其热变形激活能为361539.17J/mol,确定了Zener-Holloman参数与应变速率和温度的关系式,建立了动态再结晶临界应变模型、高温奥氏体流动应力模型和动态再结晶晶粒尺寸模型,理论模拟结果与试验结果吻合较好。     

03Cr18NiMoN节镍双相不锈钢的热变形行为及热加工图

为了探究03Cr18NiMoN节镍双相不锈钢高温轧制变形机制和组织演变规律,利用Gleeble-3800热模拟试验机在变形温度为850～1 150℃,应变速率为0.01～10 s~(-1),变形量为50%条件下对其进行高温压缩研究。流变应力曲线在950～1 150℃的较高变形温度和0.01～0.1 s~(-1)低应变速率条件下呈现出明显动态再结晶特征。变形初期,试验钢的加工硬化率随变形温度的降低和应变速率的升高而增加,不利于动态再结晶软化。组织分析表明,随变形温度升高至1 050℃和应变速率降低,奥氏体动态再结晶更加充分,晶粒细化程度明显提高,而1 150℃高变形温度使奥氏体再结晶晶粒粗化。在950℃、0.01～1 s~(-1)的变形条件下,铁素体动态回复逐渐加强。热变形激活能Q=549.7 kJ/mol,高于2 205双相不锈钢(451 kJ/mol),表观应力指数n=6.079,表明其变形机制主要以体扩散引起的位错低温攀移为主。热加工图分析表明,失稳区域随应变量增加逐渐增大,结合流变应力曲线和显微组织分析,确定最佳加工区域为950～1 050℃的变形温度和0.01～0.018 s~(-1)的应变速率,且功率耗散因子处于较高(0.36～0.50)水平。此外,基于Z参数建立了试验钢的峰值流变应力本构方程。     

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

正~~     

Zinc Production by Province in 2014

正~~     

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