120 t BOF-LF-VD-CC工艺生产GCr15轴承钢的氧含量控制

采用铁水预处理-120 t顶底复吹转炉-LF-VD-φ180 mm连铸工艺生产GCr15轴承钢.统计分析了轴承钢转炉终点[C]对钢水氧活度的影响,LF精炼渣碱度对T[O]的影响,LF末钢中铝含量对VD过程铝损和T[O]的影响.通过控制转炉终点[C]≥0.06％、出钢用铝锰铁强化脱氧;控制LF离位时[Al]0.020％ ～0.040％,( FeO+MnO)≤1％,碱度2.8～4.5;VD软吹时间≥15 min,轴承钢中全氧含量为(6～12) ×10-6.     

120 t复吹转炉吹氧后氩气搅拌工艺的冶金效果

转炉后吹氩气搅拌工艺可以更进一步促进钢液中的碳氧反应,有效降低转炉冶炼终点的钢液氧含量.通过对120 t复吹转炉的后吹氩气搅拌工艺的工业试验结果表明,后吹氩气搅拌可降低转炉终点碳氧积,底吹流量800 m3/h的氩气搅拌5 min后,[O]从吹氩前的897×10-6,降至400×10-6;(FeO)从18.5％降至13.7％,平均[S]从0.009％降至0.005％,平均[P]从0.008％降至0.006％;搅拌3～6 min钢液平均温度降低10 ～20℃.     

轴承钢全氧含量控制技术研究

转炉方坯连铸工艺生产轴承钢,分析表明：加强熔池搅拌,使钢渣充分反应,控制转炉下渣量小于5kg／t钢,加强吹氩搅拌,控制LF顶渣碱度在2．0～2．5之间,w（FeO）＋w（MnO）小于0．5％,可使轴承钢中全氧含量进一步降低。     

60 t转炉-60 t LF冶炼GCr15轴承钢氧含量的控制

石钢采用60 t转炉-60 t LF-150 mm×150 mm方坯连铸工艺生产GCr15轴承钢.工艺实践表明,采用高拉碳操作法,转炉平均终点碳含量为0.30%;改进工艺控制转炉出钢下渣量;LF精炼时采用CaO-SiO2-Al2O3高碱度渣;连铸时钢包到中间包采用套管和吹氩保护,中间包水口使用密封垫,有效地控制了钢中的氧含量.统计表明25炉轴承钢氧含量为(6.5～11.9)×10-6,平均氧含量为10.2×10-6.     

石钢GCr15轴承钢实践

介绍了石钢采用60 t BOF-LF-VD-CC流程生产GCr15轴承钢的工艺实践,重点研究了工艺过程中氧含量的控制,工艺过程为:以60 t氧气转炉作为轴承钢初炼炉,终点高拉碳,控制下渣量≤50 mm;采用高碱度(R≥3.5)CaO-SiO2-Al2O3渣系进行钢包精炼处理,实现了较好的脱硫和脱氧效果,通过合理的吹氩制度去除了更多的夹杂物;VD处理时真空度控制在67 Pa以下,保持真空时间为10～20 min,VD处理结束后进行吹氩弱搅拌4 min以上,去除了更多的夹杂物,保证了较低的氧含量;石钢施行全流程保护浇注,有效地防止了钢液的二次氧化.最终成材氧的质量分数平均为9.5×10-6,最低达7×10-6,达到了国内先进水平,实现了转炉冶炼GCr15轴承钢的高效、高质、低成本生产.     

60 t BOF-LF(VD)-150 mm×150mm连铸生产GCr15轴承钢的工艺实践

济源钢铁公司采用60 t顶底复吹转炉高拉碳操作法,控制转炉终点[C]0.08%～0.20%,出钢过程钢包底吹氩并加铝铁脱氧,LF采用CaO-Al₂O₃-SiO₂高碱度渣精炼,连铸钢水过热度20～30℃,M+F电磁搅拌,全程吹氩保护浇铸,铸坯堆垛缓冷工艺生产150 mm×150 mm GCr15轴承钢铸坯。实践表明,GCr15轴承钢的氧含量为（6.3～11.9）×10^-6,平均氧含量为9×10^-6,连铸坯的低倍组织良好。     

低氧含量GCr15轴承钢生产工艺实践

针对石钢60 t LD-LF-VD-CC生产工艺,通过开发高碳低氧出钢、控制LD出钢下渣量、LF到位白渣技术、轴承钢专用精炼造渣工艺、分阶段吹氩工艺、优化连铸工艺等系统控制技术,使GCr15轴承钢平均全氧含量(T[O])明显降低,平均T[O]从原工艺的9.6×10~(-6)降低到6.34×10~(-6),T[O]≤7×10~(-6)的炉数占到总炉数的82.8%,工艺改进效果显著。     

废钢+铁水-50 t EAF-LF-VD流程GCr15轴承钢中的非金属夹杂物行为

通过50 t EAF配加30~40 t铁水和12~16 t优质废钢,EBT无渣出钢,加150~200 kg钢芯铝预脱氧,LF用SiC扩散脱氧,控制精炼渣碱度4.0~5.9,VD前后软吹氩、连铸保护浇铸和电磁搅拌等工艺措施,GCr15轴承钢轧材中的氧含量为8×10~(-6)~9×10~(-6)。分析结果表明,LF前至VD后钢中夹杂物尺寸一般≤10μm,最大尺寸40μm,大部分夹杂物尺寸为3~6μm;LF前主要夹杂物为Al_2O_3,镁铝尖晶石,硫化物,Cr_2O_3,Ti0_2;VD前后为镁铝尖晶石,CaS和MgO。     

转炉供CSP钢水脱氧工艺与氧含量的控制研究

讨论了涟钢CSP(compactstripproduction)生产线钢水脱氧和控制工艺。根据钢水从转炉—吹氩—LF精炼—连铸各工序中氧含量的变化情况,对现行铝脱氧工艺进行了改进。出钢后通过采取钢水全程吹氩,钢水浇铸时,在大包—中间包采用长水口 氩气密封,结晶器采用浸入式水口 保护渣控制措施后,成品钢水中全氧含量得到了有效控制,其含量在35×10-6的水平,满足了CSP工艺对钢水的质量要求。     

150 t转炉-LF-RH-350 mm×470 mm CC流程生产优质轴承钢GCr15的工艺实践

通过采用优质铁水,高拉碳操作控制顶底复吹转炉终点[C]≥0.20％,LF精炼造渣材料加入前[Als]≥0.03％,精炼渣(FeO+ MnO)≤1.0％,RH≤100 Pa的时间≥15 min,连铸钢水过热度≤30℃,结晶器电磁搅拌和凝固末端动态轻压等工艺措施,本钢GCr15轴承钢的平均T[O]≤8×10-6,[Ti]≤25×10-6,[Ca]≤10×10-6,连铸坯中心疏松0.5 ～1.0级,缩孔0～1.0级,等轴晶率41.5％ ～43.2％.     

Chinalco Signed Framework Agreement for Strategic Cooperation with Harbin Municipal Government

正Last month,Chinalco signed framework agreement for strategic cooperation with Harbin Municipal Government in Harbin Xiong Weiping,Chairman of Chinalco,said that based on the strategic deployment to build world top-class mining company with the highest growth potential,Chinalco was now concentrating all efforts on making strategic transition and structural adjustment,strategic cooperation with the local governments where     

Jiangxi Promotes Jiangxi Copper Corporation To Become The World's Most Competitive Mining Company

<正>According to the latest info from Jiangxi Province State-owned Assets Supervision and Administration Commission,Jiangxi Copper Corporation was approved to become the first pilot enterprise for deepening reform.Contents of the pilot work is"Three Self"(self expansion,self decision-making,self     

Journal of Rare Earths Contents List of Vol.32(2014)

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Contributions to Baosteel Technical Research wanted

正Baosteel Technical Research,a quarterly journal,which is issued domestically and abroad,is run and sponsored by Baosteel Group Corporation.Baosteel Technical Research mainly reports the achievements in technological innovation,academic research,new product development and industrial equipment improvement by Baosteel.It will continue to follow up on hot topics and serve the company’s technological development and progress.Its readers include experts in     

Ministry of Industry and Information Technology: No Short Term Solution For Our Country’s Excess Nonferrous Metal Smelting Capacity

【正】According to the Ministry of Industry and Information Technology,the Ministry has released the 2013 Operation Report on China’s Industrial Communication Indu...     

Chinalco Signed Framework Agreement for Strategic Cooperation with Gansu Province

正Recently,Chinalco and Gansu Provincial People’s Government signed"Framework Agreement for Strategic Cooperation on Reform,Restructuring and Transition Development of Chinalco’s Electrolytic Aluminum Enterprises in Gansu",signifying that the strategic cooperation between Chinalco and Gansu Province had made new substantive progress.     

Unavoidable Economic Cycle:30% Of Nonferrous Metal Companies Were Involved In Restructuring

正Owing to continual downturn in real estate and bulk commodity markets,a number of traditional industries in China suffered unfavorable impact in performance.With the progressive disclosure of third quarter report,the no-pleasant-surprise performance of     

Baotou Rare Earth Became the World's Biggest High Performance Magnetic Material Base

正The High Performance Magnetic Material Phase II Project,an industry upgrading project implemented by Inner Mongolia Baotou IronSteel Rare Earth(Group)Hi-tech Co.,Ltd,recently basically finished equipment commissioning,signifying that the enterprise had developed the production capacity of15000 t/a Nd-Fe-B strip casting alloy and 5000t/a Nd-Fe-B magnet,thus becoming the world’s     

Introducing Two Central Enterprises to Integrate Rare Earth Industry,Shandong Rare Earth Group Breaks Surface

正With the signing of"Letter of intention for Propelling Integration of Shandong Rare Earth Enterprises"between Shandong Province Commission Of Economy and Informatization,China IronSteel Research Institute Group("China Steel Institute"),and China Rare MetalsRare Earth Co.,Ltd("China Rare Earth"),the"Shandong Rare Earth Group"jointly set up by the 3 units thus broke surface.On August 9,reporters of the China Economic Herald learned from Shandong Province     

Aluminium Production by Province or City in 2014

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