冶炼工艺对新型不锈轴承钢的冶金质量和接触疲劳寿命的影响

介绍了采用双真空冶炼工艺和电渣重熔冶炼工艺生产新型不锈轴承钢的研究情况。研究结果表明,采用真空感应炉＋真空自耗炉（双真空）冶炼工艺生产的新型不锈轴承钢6Cr14Mo,钢中氧含量为0．0005％,而电渣钢的氧含量为0．0029％。双真空钢的氧化物夹杂数量较少、颗粒尺寸也比较细小。双真空钢的碳化物尺寸、形态及分布均优于电渣钢。双真空钢和电渣钢的接触疲劳额定寿命L10分别为0．66×10^7和0．40×10^7,前者是后者的1．65倍。     

全封闭Ar气保护电渣重熔GH4169合金

上海五钢采用ALD 5t全封闭Ar气保护电渣重熔炉 ESR(Ar)冶炼了GH4 16 9合金锭 ,分析结果表明 ,ESR(Ar)电渣锭氧、硫含量和锭头尾碳、铝、钛之差远低于一般ESR工艺 ;VIM(真空感应熔炼 ) +ESR(Ar)工艺冶炼合金中平均氧含量 6× 10 - 6 远低于VIM +VAR(真空电弧重熔 )工艺冶炼合金中平均氧含量 13× 10 - 6 ,所以ESR(Ar)工艺脱氧效果优于VAR工艺     

GCr15轴承钢冶炼工艺分析和讨论

采用非真空钢包精炼及钡合金处理轴承钢工艺 ,可使轴承钢氧含量降到 10× 10 -6 以下 ,在钢的氧含量为 8× 10 -6 时 ,钡合金处理钢的疲劳寿命比铝处理钢高 63 5 5 %。     

日本轴承钢生产现状

近年来,日本各轴承钢生产厂家不断采用新技术、新工艺,使轴承钢氧含量和夹杂物含量不断降低,最低氧含量达3ppm,疲劳寿命不断提高,L10达4.7×10~7以上,达到了电渣钢和真空电弧重熔钢的水平。     

轴承钢电渣重熔过程中氧的控制及作用研究

研究了不同氧含量（（５～４０）×１０－６）的自耗电极及重熔渣系对轴承钢氧含量、夹杂物和疲劳性能的影响，结果表明：①无论用高氧含量（＞３０×１０－６）自耗电极还是低氧含量（＜１０×１０－６）自耗电极重熔，电渣钢中氧含量都保持在（１５～３０）×１０－６；②影响电渣钢中氧含量的决定因素是渣中的ａＦｅＯ值，自耗电极中的原始氧含量影响较小；③电渣重熔过程中，自耗电极中原始夹杂可基本去除，重熔钢中的夹杂主要是金属熔池冷却结晶过程中新生成的。     

钢包埋弧精炼渣优化研究

针对使用原埋弧精炼渣存在钢中氧含量和点状夹杂物级别较高的问题 ,通过降低碱度和Al2 O3含量及采用钡合金 ,开发了 1种以CaO SiO2 Al2 O3 CaF2 为基础成分的埋弧渣 ,使轴承钢氧含量平均达 9.5 7× 10 - 6 ,弹簧钢氧含量平均达 15 .13× 10 - 6     

石钢降低钢中氧含量生产实践

介绍了石钢转炉厂为降低钢中氧含量采取的一系列措施,如高拉碳、提高一次倒炉率、降低出钢温度、控制下渣量、精炼白渣脱氧等,氧含量由2001年的50.04×10-6下降到2004年2月的19.13×10-6,取得了显著效果,钢材质量明显提高。     

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。     

炉衬产生的氧对真空钢液脱氮的动力学影响

采用 99.99%氧化镁砂捣打炉衬的 2 0kg真空感应炉 ,研究了超低碳钢熔炼时炉衬产生的氧对真空钢液脱氮的影响。试验结果表明 :钢液中氧含量在 1 2 0× 1 0 - 6 时 ,脱氮的限制性环节是界面化学反应 ;随炉衬中氧的逸出 ,当钢液中氧含量在 5 1 0×1 0 - 6 时 ,真空钢液脱氮处于界面化学反应和液相边界层扩散控制的边缘区域 ,脱氮速率降低     

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 。     

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.