高氮Fe-Cr-Mn-Ni系奥氏体不锈钢的加压感应熔炼

采用MgO坩埚高频真空感应炉在氮气压力0.45~1.0MPa、温度1640~1700℃下,对加压感应熔炼高氮Fe-Cr-Mn-Ni系奥氏体不锈钢进行了实验研究。结果表明,1913K、1.0MPa氮气氛中Cr12、Cr17Mn5Ni5、Cr19Mn15和Cr20Mn8不锈钢中氮的溶解度分别为0.391%、0.692%、1.120%和0.899%,氮在液态不锈钢中的溶解与Sievert定律有所偏离;氧浓度在350×10^-6内,1913K、1.0MPa氮气氛中Cr20Mn8钢液的吸氮反应仍为一级反应,其传质系数为0.023cm·s^-1;随钢中氧浓度的增加,液态钢的吸氮速率和钢液中的平衡氮含量显著降低。     

AOD炉冶炼含氮不锈钢氮合金化工艺开发

介绍了AOD炉运用氮气在不锈钢中溶解与脱除理论所开发的氮合金化工艺。在40tAOD炉上冶炼0Cr19Ni9N,0Cr19Ni9NbN,1Cr17Mn6Ni5N,00Cr18Ni5Mo3Si2（N）,00Cr22Ni5Mo3N等舍氮不锈钢钢种。不需在线分析钢中氮含量，较为准确地预测与控制钢中氮溶解度值及舍氮不锈钢成品的氮含量。     

Ni、Cr对钢液表面氮溶解速率的影响

采用氮同位素气体交换技术实验测定了Fe-Cr、Fe-Ni和Fe-Cr-Ni体系在1 873 K时的氮溶解反应速率常数,分析讨论了Cr、Ni含量对氮溶解反应速率常数的影响,并计算获得了Cr和Ni的吸附系数。结果表明,随着钢液中Cr和Ni含量的增加,表面氮的溶解反应速率常数增大。在Fe-Cr-Ni体系中,Cr的吸附系数为-0.01,Ni的吸附系数为-0.03,氮溶解速率常数入。与Cr、Ni含量的关系式可表达为k_a=(4.53×10~(-6))/(1(1-0.01[%Cr]-0.03[%Ni])~2)。     

AOD冶炼不锈钢氮合金化控制模型的研究和应用

根据氮在钢中的溶解热力学和脱除动力学理论,建立了AOD精炼氮合金化的控制模型。经45 t AOD装置精炼0Cr19Ni9N不锈钢(%:≤0.08C、18～20Cr、8～11Ni、0.10～0.16N)的应用结果表明,模型计算值与实测值吻合良好,可通过AOD氮气溶解和氩气脱除,精确控制不锈钢的N含量。     

底吹氮气冶炼高氮不锈钢的应用研究

根据对高氮不锈钢冶炼设备和工艺、氮气在高温高压下溶入钢液中的方式和特点,以及底吹增氮的优势的分析,在实验室通过300 g钢水底吹异型坩埚在0.5～1.5 MPa,氮气底吹流量0.14～0.24 m~3/h,1820～1910 K下对高氮不锈钢Cr18Mn18N(/%:0.17C、18.00Cr、18.09Mn、0.25Si、0.010S、0.020P、1.07N)进行增氮试验。结果表明,在1.5 MPa、1890 K,0.15 m~3/h底吹氮气流量下,当底吹时间20～30 min氮含量趋于饱和,可快速冶炼出氮含量≥1.0%高氮不锈钢,具有良好的工艺效果。     

高频燃烧红外吸收法测定高锰不锈钢中痕量硫的助熔剂选择及其作用机理研究

针对高频燃烧红外吸收法测定高锰不锈钢中痕量硫的结果严重偏低现象,以Cr18Ni5Mn10Mo3和GH139高锰不锈钢为试验样品,考察助熔剂的种类、配比、加入顺序及称样量对测定的影响。同时,借助热分析仪对助熔剂的高温氧化行为进行了分析,探讨了助熔剂的作用机理,为助熔剂的选择提供了理论依据。试验结果表明,Cr18Ni5Mn10Mo3和GH139不锈钢的最佳助熔剂用量及样品加入顺序分别为0.5 g纯铁+0.25 g样品+0.5 g锡+2.5 g钨和0.5 g锡+0.7 g纯铁+0.20 g样品+0.5 g三氧化钼和五氧化二钒的混合物(m(MoO₃)∶m(V₂O₅)) +1.5 g钨。用本方法测定了2个高锰不锈钢标准样品中的硫量,测定值与认定值相符,测定结果的相对标准偏差分别为7.2%和4.5%（n=6）。     

冷变形及热处理工艺对奥氏体不锈钢0Cr18Ni12和0Cr16Ni14组织及磁性能的影响

从成分和组织稳定性,探讨了冷变形(0%～80%)及1000～1090℃固溶处理对0Cr18Ni12与0Cr16Ni14奥氏体不锈钢组织及磁性能的影响。结果表明:0Cr18Ni12与0Cr16Ni14不锈钢奥氏体稳定性优于SUS304,其中0Cr16Ni14奥氏体稳定性最佳;0Cr18Ni12与0Cr16Ni14不锈钢冷变形过程中均产生形变马氏体,0Cr16Ni14冷变形过程中相对磁导率始终保持在1.010以下,0Cr18Ni12形变马氏体比例最大可达3.5%,相对磁导率增大至1.353,经固溶热处理后,相对磁导率可控制在1.010以下;结合现场生产条件,制定出两种奥氏体不锈钢的固溶处理工艺为1060℃每毫米保温80s。     

合金元素及凝固模式对含氮不锈钢氮含量的影响

通过冶炼实验研究Mn、Cr和Ni对不锈钢凝固模式及铸锭氮含量的影响,探讨影响氮含量的关键因素,并分析合金元素对钢液与铸锭中氮含量影响的相互作用系数的区别.实验结果表明,影响氮含量的因素主要为钢液中氮的溶解度和不锈钢的凝固模式.增加钢液中氮的溶解度、改变凝固模式由F→FA→AF→A时,不锈钢的溶氮能力提高,氮气的溢出量减少,氮含量增加.随Mn含量增加,铸锭中氮含量线性增加,而随Cr和Ni含量增加,氮含量的变化均存在三个特征阶段.分析认为:Mn含量变化不改变凝固模式（FA）,相互作用系数E_NMn为-0.0286,与钢液中相近;而随Cr和Ni含量增加,凝固模式分别依次经历F→FA→AF→A和FA→AF→A模式,相互作用系数E_NCr和E_NNi非定值,分别为E_NCr=-0.046和-0.011,E_NNi=-0.011和0.033.      

Cr、Mo对超低碳双相不锈钢的σ-相析出行为和耐点蚀性能的影响

通过Thermo-Calc热力学计算、金相和电化学方法分析和研究了1 050~1120℃固溶的00Cr21Ni2Mn5N、00Cr22Ni5Mo3N、00Cr25Ni7Mo3N、00Cr27Ni7Mo5N四种典型超低碳双相不锈钢在5001~100℃时效后σ相的析出规律和σ相含量对四种双相不锈钢点蚀电位的影响。结果表明,σ相析出量随着时效温度的升高呈现先增加后减小的趋势,并且随着双相不锈钢中铬-钼含量（/%）依次20.98-0.03,22.41-3.16,25.30-3.46,26.69-4.74递增时,σ相析出量峰值递增,依次为4.9%,22.5%,27.0%,40.5%,同时σ相完全溶解温度提高,依次为660,950,1 060,1100℃;σ相析出量越大超低碳双相不锈钢耐点蚀性能越低,4种钢的σ相析出峰值对应的E_b100值依次为-94.0,100.1,260.2,117.7 mV。     

超塑性奥氏体-铁素体双相不锈钢00Cr25Ni7Mo3N的研制

通过电弧炉-电渣重熔工艺开发研制了成分为(%):0.021C,24.16Cr,7.21Ni,2.87Mo,0.17N,0.48Cu超塑性双相不锈钢00Cr25Ni7Mo3N。试验结果表明,00Cr25Ni7Mo3N超塑性双相不锈钢的耐孔蚀性和耐缝隙腐蚀性远高于传统的304L和316L奥氏体不锈钢。在变形温度960℃、应变速率2×10^-3/s时,00Cr25Ni7Mo3N超塑性双相不锈钢的最高延伸率为960%,该钢超塑性变形的均匀性优于TC4钛合金,可显著减轻构件的重量。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

Shijiazhuang will Build the World's Biggest Replacingcopper-with-aluminum Cable Production Base

正Shijiazhuang City will build the world’s biggest replacing-copper-with-aluminum cable production base,the annual output value can reach 100 billion yuan,in the future it will develop replacing-copper-with-aluminum highend industry cluster.This piece of news was learned by the reporter at the Rare Earth highiron Aluminum Alloy[Nonferrous Business Opportunity:Aluminum alloy door]Cable Conductor New Technology Application Seminar held at the provincial capital.     

Chongqing is Preparing to Set Up Nonferrous Metal Exchange,in a Bid to Become the Transit Place of Kazakhstan Copper

正Since the beginning of Chongqing’s upgrading to a municipality directly under the Central Government,Chongqing City has established direct friendly relationship with Almaty,Kazakhstan,and carried out a series of cooperation in commerce and trade,and culture     

Guangxi Baise Extends Industrial Chain to Combat Loss in Aluminum Business

正"For each tonne of aluminum being produced,the upstream enterprise on the aluminum industrial chain will suffer loss about 2000yuan."Said Liang Xiao,Deputy Director of Pingguo Industrial Park Management Committee under the Guangxi Baise City,one of the four major aluminum industry bases in China,on August 11.Extending aluminum     

JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL ANNUAL CONTENTS Volume 21(2014)

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Chinalco Straightened Out Copper Assets,and Delegated Stock Equity of Yunnan Copper

正Immediately after the news that Chinalco transferred 58%stock equity of Yunnan Copper Group to its wholly-owned subsidiary China Copper Corporation Limited free of charge was disclosed on July 9,many individual investors couldn’t help but to think:Does it mean China Copper Corporation Limited will assemble assets for overall listing?At present,among main copper business companies under China Copper Corporation     

The Development and Reform Commission Encourages Private Capital to Enter Geological Prospecting Field

正At the press conference recently held by the National Development and Reform Commission under the theme"Deepen Reform in Investment AuditApproval System",when answering questions from reporters,Huang Min,Director of the Department of Fixed Assets Investment of the National Development and Reform Commission,said that in the future it would continue to intensify efforts in geological prospecting,and actively guide social capital to enter this field.     

Guangxi's first Nickel Industry Development Research Report Was Released

正Recently,Guangxi Metallurgical Research Institute,a subsidiary of Guangxi Nonferrous Metals Group,completed survey on laterite and related manufacturers in the region,by combining the current development status of laterite both at home and abroad,it compiled Guangxi’s first"Research Report on the Development of Guangxi Nickel Industrial Chain"which adopted laterite as the study subject.This report expounded on the current     

China’s Major Non-ferrous Metals Imports & Exports(End of September. 2014)

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China's Major Non-ferrous Metals Imports & Exports

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