降低汽车齿轮钢氧含量的工艺实践

分析和研究了用 30 t EBT电弧炉 40 t LFV精炼工艺冶炼Mn Cr、Cr Mo、Cr Ni Mo系等汽车用新型齿轮钢时 ,真空度、精炼渣、吹Ar工艺和 [Al]s对钢中氧含量的影响 ,得出真空度小于10 × 133Pa ,吹Ar 100～150 L/min ,精炼渣碱度25～30 ,控制 [Al]s为0.02%～0.04%时可以获得低氧含量。生产结果表明 ,Mn-Cr系、Cr-Mo系和Cr-Ni-Mo系齿轮钢氧含量为(12～20 )× 10^-6 ,达到汽车用新型齿轮钢氧含量的标准要求     

高品质齿轮钢28MnCr5的开发

山东莱芜钢铁集团股份有限公司采用"EAF→LF→VD→CC"工艺开发了28MnCr5齿轮钢,通过精确控制钢中C、Si、S、P等元素,得到能够满足成分要求的钢水。试验结果表明:采用该工艺生产高品质汽车用28MnCr5齿轮钢铸坯w(T.O)≤15×10-6,夹杂物种类、形态和尺寸得到有效控制,淬透性满足要求。     

20CrMnTiH齿轮钢氧含量的控制实践

通过60 t LD→60 t LF→CC工艺生产20CrMnTiH齿轮钢的实践表明：转炉采用低拉增碳操作法,控制终点碳在0.05%～0.12%、温度控制在1640℃～1660℃、出钢下渣量控制小于30 mm、采用复合脱氧工艺;精炼采用Si-Al-Ca渣系,控制炉渣碱度R≥3.5,合理控制精炼节奏及吹氩模式;连铸采用全保护浇铸等一系列措施,可把氧含量控制在18×10-6以下,满足了汽车齿轮行业标准的要求,实现了齿轮钢的批量生产。     

齿轮钢20CrMoH脱硫的热力学研究

 采用LD LF RH CC的工艺路线,出钢采用Al脱氧,造高碱度低氧化性精炼渣,生产高品质汽车用齿轮钢20CrMoH。使用KTH模型和推导硫分配比公式对生产过程的硫容量和硫的分配比进行了计算,将预测与实测的硫分配比进行对比;并对整个精炼过程的脱硫效果进行了分析。     

齿轮用19CrNi5钢的研制

介绍了依维柯汽车齿轮用钢19CrNi5的研制情况,针对该钢种的主要技术要求确定试生产工艺,在关键工艺点实施控制,使产品的实物质量满足了用户要求,实现了依维柯系汽车齿轮用钢的国产化。     

汽车用低碳齿轮钢的LF-VD 脱氧工艺

分析和研究了105炉SCM318H、SCM322H、SCM420KC、SCM822H、SCr420K等汽车用低碳齿轮钢的20tLFVD精炼终渣碱度、终Al含量和真空时间对钢中氧含量的影响。实践操作结果表明,采用白渣操作,控制终渣碱度不低于3,终Al含量≥0.22%、真空处理时间不低于25min,可使低碳齿轮钢的氧含量稳定地≤15×10^-6,平均氧含量为11.58×10^-6。     

汽车用特殊钢中夹杂物控制技术的研究进展

以弹簧钢、轴承钢、齿轮钢为例,介绍了近年来汽车用特殊钢中夹杂物控制的新进展,对弹簧钢、轴承钢和齿轮钢中夹杂物控制技术特点进行了总结.分析了碱金属氧化物、精炼渣和耐火材料对弹簧钢夹杂物塑性化控制的影响,对轴承钢和齿轮钢中比较受关注的Ds类夹杂物的形成机制研究进行了阐述,最后对齿轮钢中常见的MnS的形态控制方法进行了介绍.     

汽车用易切削钢SAE1141生产实践

通过精炼过程中控制精炼渣组元、加强沉淀及扩散脱氧强度、合理的底吹氩制度等措施,采用60t转炉冶炼-LF精炼-VD-连铸-连轧工艺,成功生产了汽车用易切削钢SAE1141,该钢的各项性能指标能够满足汽车用钢要求。     

高品质变速箱齿轮用钢xcs-23的研发

xcs-23齿轮钢是一种新型的高品质变速箱齿轮用钢。通过优化连铸生产工艺与轧钢加热时间来改善钢材的纯净度与带状组织;研究了该齿轮钢的关键理化性能,实现了淬透性的稳定控制,纯净度的提升和奥氏体晶粒度的有效控制。     

降低钢中全氧含量的精炼工艺技术

为实现高品质低氧钢的生产,有效降低钢中全氧含量,在考虑转炉下渣、炉渣氧化性以及钢水氧活度影响的前提下,通过研究钢包渣改质技术、过程钢包渣氧化性控制技术以及相应的钢包底吹氩制度等精炼工艺,建立了转炉一连铸流程生产低氧钢的精炼工艺技术。采用该技术生产的高品质优特钢成品ω（[TO]）≤15×10。     

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.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.