超洁净钢和零非金属夹杂钢

应针对不同钢种和用途 ,应用相应的精炼技术 ,达到超洁净钢对纯净度的要求 ,诸如超低硫钢要求 [S]≤ (5～ 10 )× 10 - 6 ,超低磷钢 [P]≤ 2 0× 10 - 6 ,低氮钢 [N]≤ 2 0× 10 - 6 ,显微夹杂钢要求钢中夹杂物尺寸≤2 0 μm等。零非金属夹杂钢为钢中夹杂物高度弥散、夹杂物尺寸≤ 1μm的钢。从理论上分析了零非金属夹杂钢制备的可能性。探讨了采用冷坩埚真空感应悬浮熔炼制备零夹杂钢的冶金工艺。采用中频感应炉熔炼 ,真空感应炉初精炼 ,真空凝壳炉或真空电子束熔炼深精炼可使超洁净钢中的Alsol<10× 10 - 6 ,[S]<10× 10 - 6 ,[T .O]<2× 10 - 6 ,[N]<15× 10 - 6 。     

120 t转炉冶炼GCr15轴承钢的工艺实践

采用高炉铁水预处理使[S]≤0.005%,120 t转炉高拉碳法吹炼控制出钢碳含量≥0.40%,磷含量≤0.010%,并使用低碱度CaO-Al2O3渣系,钢包炉(LF)精炼,采用弱氩气搅拌及3 t铸锭工艺,得出GCr15轴承钢材的A、B类夹杂物为1.0级,C、D类0级,[O]≤10×10-6,钢材质量达到YJZ-84标准要求.     

150t转炉-LF＋RH流程生产GCr15轴承钢的有害元素控制

本钢炼钢厂采用铁水脱硫-150 t转炉-LF+RH-TB精炼-350 mm×470 mm坯连铸流程生产GCr15轴承钢.通过使用优质铁水(%:0.000 2Ca、0.002 7Cu、≤0.001As、≤O.001Sn、≤0.001Sb、0.002Pb),控制铁水中[P]≤0.040%,[S]≤0.003%,转炉出钢合金化后[Ti]为12×10-6,控制LF+RH精炼过程增[Ti],LF末期[Als]0.04%等工艺措施,有效地控制GCr15轴承钢的有害元素,使成品钢[Ti]≤30×10-6,[Ca]≤8×10-6,[0]≤8×10-6,[N]≤38×10-6,[H]≤0.8×10-6,轧材低倍、夹杂物等指标均达到标准要求.     

真空脱气炉在电炉炼钢中的应用

介绍真空脱气炉的控制系统,以及真空脱气的操作要点等.杭钢电炉钢水经真空脱气处理后,[H]可降到2×10-6以下,[N]降至80×10-6以下,吨钢收益明显增加.     

[S]对低合金洁净钢强度与冲击韧性的影响

对[P]+T[O]+[N]<80×10-6的低合金洁净钢中[S]对钢板强度与冲击韧性的影响进行了实验研究。研究发现,[S]低于50×10-6时,钢板强度随[S]增加而降低;而当[S]高于50×10-6时,[S]含量的变化对钢板的强度影响不大;钢板韧脆转变温度随[S]降低而降低,试样长度方向和宽度方向的韧脆转变温度间的差距随[S]的降低而减小,但[S]减少到10×10-6以下时,其差距仍高达16℃。     

转炉-ANS-连铸工艺生产低碳铝镇静钢洁净度研究

采用转炉-ANS精炼-连铸工艺生产低碳铝镇静钢,ANS处理后钢液T[O]含量在(35～56)×10-6之间,铸坯T[O]含量在25×10-6左右.钢液氮含量与转炉出钢过程预脱氧加铝量有关,在钢液氮含量非常低的情况下,ANS处理后钢液仅增氮3×10-6.铸坯中主要的非金属夹杂物为微小的块状Al2O3夹杂物和少量较小尺寸的簇群状Al2O3夹杂物,铸坯中尺寸大于50 μm的大型非金属夹杂物含量低于1 mg/(10 kg).     

改善套管钢冶炼过程浸入式水口堵塞

 通过金相分析、扫描电镜、能谱分析等手段对国内某钢厂生产石油套管钢的水口堵塞物进行了分析,对冶炼过程Al2O3夹杂的控制问题从热力学角度进行了研究。热力学计算结果表明,当钢中的 [Al]s含量为0.025%,若钙处理时钢中钙含量高于22×10-6,硫含量低于0.008%,可较容易地将Al2O3夹杂变性为低熔点易上浮的C12A7。在热力学计算基础上,通过强化钢水钙处理,钢中钙含量提高至25×10-6～40×10-6,夹杂物变性上浮容易,连浇炉数由3～4炉提高至大于8炉。     

转炉—RH—连铸工艺生产高压气瓶用钢洁净度的研究

对转炉— RH精炼—连铸工艺生产高压气瓶用钢 T[O]变化及非金属夹杂物进行研究的结果表明 ,在转炉出钢过程由于炉渣与脱氧产物作用生成的粗大球状夹杂物及铝脱氧生成的大尺寸 Al2 O3簇群状夹杂物绝大多数可由钢液排除 ,铸坯中存在的夹杂物主要是较小的块状和簇群状 Al2 O3及少量由于结晶器保护渣卷入造成的球状夹杂物。 RH精炼后钢液 T[O]在 (2 8～ 34 )× 10 - 6 之间 ,中间包钢水 T[O]在 (2 4～ 2 6 )× 10 - 6之间 ,铸坯 T[O]在 (12～ 19)× 10 - 6 之间 ,该工艺生产的气瓶用钢具有很高的洁净度。     

RH-喂线钙处理的管线钢X80非金属夹杂物变性效果分析

在钙处理对夹杂物变性作用进行分析的基础上,结合钢厂生产X80管线钢(%:≤0.08C、≤1.85Mn、≤0.060Als)的工业性试验,利用冶金热力学原理,分析计算了Al₂O₃变性为低熔点钙铝酸盐所需钙含量的范围和避免单相CaS析出硫含量的范围,同时对≤0.002%S和0.025%～0.035%Al的RH处理钢水按出站[Ca]_Tot=(40～50)×10-6计算喂Ca-Si线进行钙处理,并对中间包钢水和铸坯中的夹杂物进行了检测。结果表明,X80管线钢试验炉次平均[Ca]_Tot为41×10^-6,[S]为23×10^-6,均在理论计算范围内;同时经钙处理后,钢中绝大部分夹杂物CaO-CaS-Al₂O₃复合夹杂,钙处理效果良好。     

宝钢RH装置及其相关因素的探讨

一、概况宝钢RH装置在1985年11月23日～1988年4月30日,共计处理2289炉次,处理量约68.8×10~4t,钢种66个。按照新日铁和曼内斯曼企业标准检验合格率达到99％以上,钢管钢坯夹杂物级别k_4值按规定≤60,实际平均值为7.94,k_4≤30的试片占90.7％。塔形无发纹率为34.9％。另外,通过超声波探伤对比试验,发现经RH处理的钢探伤合格率由43.6％提高到82.1％。经过RH本处理的钢液,可使[H]<1.8ppm,[N]<5.ppm,[O]_(自由)<10ppm,脱氢率约64％,脱氧率约49％,脱氮率16％左右。RH OB法精炼低碳铝镇静     

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。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.