带钢冷弯不合格的原因分析与控制

针对带钢存在的冷弯断裂及分层现象多、冷弯一次合格率低的问题,采用XL30扫描电镜、金相显微镜等,对冷弯不合格的带钢取样进行组织、夹杂物、晶粒度、断口等检验和氧含量分析并与正常试样对比。结果表明:钢中氧含量高、夹杂物多是导致带钢冷弯不合格的主要原因。通过采取炉前加大脱氧剂用量,对夹杂物进行变性处理等深脱氧技术及保护浇注,优化连铸工艺等措施,钢材全氧含量由153.5×10-6降到100×10-6,冷弯一次合格率由97.5%提高到99.0%。     

真空感应炉炉衬材质对Inconel 690合金纯净度的影响

 为了研究坩埚材质对真空感应炉熔炼镍基合金Inconel 690纯净度的影响,在200、500kg真空感应炉上,分别使用镁质坩埚、钙质坩埚、铝镁质坩埚冶炼了Inconel 690合金,分析了产品中全氧含量、硫含量及氧化物夹杂数量、尺寸。真空感应炉铝镁质坩埚冶炼的产品全氧含量可达到(10~15)×10-6(质量分数,下同),硫含量55×10-6,合金中存在粒径5~10μm的D类夹杂物和粒径50μm以下的B类夹杂物,产品纯净度较高。钙质坩埚冶炼的产品硫含量可达到10×10-6,全氧含量平均为33×10-6,合金中存在大量的粒径5~10μm的D类细小夹杂物,同时存在少量粒径50~100μm的大型钙硅酸盐夹杂物。镁质坩埚冶炼的合金中全氧、硫含量分别为28×10-6、55×10-6,存在大量粒径50μm以上的B类氧化物夹杂。Inconel 690合金通常采用真空感应炉加电渣重熔的工艺路线生产,不考虑硫含量对纯净度的影响,建议真空感应炉采用铝镁质炉衬冶炼Inconel 690合金。     

低碳盘条弯断原因分析及控制

阳春新钢铁生产不同规格的低碳低硅盘条,在酸洗拉拔折弯时出现部分产品弯断。文章以不同规格弯断样为研究对象,通过断口晶粒度均匀性以及高倍电镜下的显微断口状态分析,找出弯断原因。结果表明:弯断样主要存在的问题为断口晶粒均匀性存在大小晶粒差异;断口面存在外来夹杂物;断口韧窝有颗粒状非金属氧化夹杂物。根据缺陷类型提出了相应的优化控制措施。     

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。     

60Si2MnA弹簧钢脱氧工艺的优化

在现场调研的基础上 ,对用 30 t L F生产 6 0 Si2 Mn A弹簧钢的脱氧工艺进行优化控制。结果表明 :在不进行夹杂物变性处理的条件下 ,可生产出平均氧含量为 2 3× 10 - 4 %、最低氧含量为 16× 10 - 4 %的 6 0 Si2 Mn A弹簧钢     

用钡合金进行钢水脱氧的实践

为了提高轴承钢、齿轮钢和弹簧钢的洁净度,对影响其质量的各种因素进行了分析,提出了以铝预脱氧为基础、用钡合金进行终脱氧和夹杂物变性的脱氧工艺,使轴承钢、弹簧钢和齿轮钢的氧含量分别稳定在10×10-6、15×10-6及20×10-6以下,并使夹杂物的组成和分布得到改善.     

风力发电机主轴用材料17CrNiMo6低温冲击性能影响因素分析

主要研究了风力发电机主轴用17CrNiMo6钢的低温冲击性能的影响因素。结果表明:钢中氧含量、夹杂物、金相组织、晶粒度对钢的低温冲击性能均有影响。     

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).     

ER70S-6钢氮氧含量控制

为了降低气保焊丝钢ER70S-6最终产品的氮氧含量,提高焊丝的成材率,改善焊丝的焊接冶金性能,国内某生产厂实行转炉、精炼、连铸全流程控氮氧措施。结果表明:转炉环节氮质量分数降低了3×10-6,精炼工序氮质量分数降低了4×10-6,连铸大包至中包氮质量分数降低了2×10-6,全工艺环节总氮质量分数下降了约11×10-6,轧材成品全氧质量分数平均下降了27×10-6。在夹杂物及组织方面,低倍金相图片显示夹杂物的总体数量有所减少,存在形态由颗粒状及链状变为不连续的点状,分布状态由聚集态向弥散转变,同时高倍金相图片显示,晶粒略有增大,晶粒度有所下降,夹杂物沿晶界析出状况有所好转。     

稳定Q235B板材冲击性能的试验研究

针对生产中出现规格40～50mmQ235B板材冲击性能不足的原因进行分析.通过检测试验以及工艺过程分析,不合格板材试样夹杂物及氧含量较高、晶粒较粗,降低了钢材的冲击韧性.本文提出通过炼钢过程的精细控制,降低氧含量及减少钢中的夹杂物;优化轧钢控轧控冷工艺及合理控制压缩比,改善板材组织并细化晶粒,从而使得板材冲击性能得到明显提高.     

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

正~~     

Zinc Production by Province in 2014

正~~     

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.