VOD冶炼工艺在马氏体不锈钢ZG06Cr13Ni4Mo上的应用

介绍了EAF+LF+VOD工艺冶炼三峡水轮机叶片用ZG06Cr13Ni4Mo马氏体不锈钢的过程。EAF采用优质原材料有效控制P含量;LF调整成分、温度、脱硫;VOD精炼控制吹氧真空度、吹氧强度、氧枪高度、氩气流量等工艺参数,并结合氧势图和废气温度准确判断停吹氧时间。结果表明,产品最终[C]=0.033%,VOD过程降C速率达到每分钟0.01%,Cr回收率达到93%,气体含量也达到了较低水平,[N]=34×10-4%,[H]=1.7×10-4%,[O]=36×10-4%。     

中频炉和VOD双联法冶炼不锈钢工艺

介绍了中频炉熔炼及VOD精炼X3CrNiMoN27-5-2不锈钢的生产工艺及措施.采用优质原材料,调整化学成分及出炉温度,控制VOD精炼炉吹氧真空度、吹氧强度、吹氧时间、氩气流最等工艺参数,并结合氧势图和废气温度,准确判断吹氧终点时间和极限真空保压时间,其冶金效果可以达到铸件材质的质量标准.     

用低碳镁碳砖钢包冶炼低碳不锈钢生产实践

介绍了用低碳镁碳砖钢包VOD、VD工艺冶炼低碳不锈钢的试验情况,分析讨论了低碳镁碳砖对冶炼过程的影响。钢包精炼炉低碳镁碳砖VD工艺可冶炼C≤0.06%、VOD工艺可冶炼C≤0.04%的不锈钢。     

不锈钢生产的三联工艺

德国曼内斯曼迪马克冶金技术公司开发了一种生产不锈钢的三联工艺,即:EAF(电弧炉)-MRP-L(使用氧枪的金属精炼转炉)—VOD(真空吹氧脱碳装置)。这套工艺和设备已于1988年4月在比利时的ALZ厂投产。其电弧炉、转炉和VOD装置的出钢量分别为85t、100t和100t。在该工艺路线中,偏心炉底出钢型电弧炉仅用作熔化装置,从出钢到出钢的时间为75min。MRP-L转炉主要用作快速脱碳装置,它配有2支可移动式氧枪,1根为工作     

影响VOD精炼的工艺因素

以工业试验和生产数据为基础,对不锈钢VOD法进行了分析,讨论了影响VOD过程的工艺因素。结果表明:通过合理控制真空度、氧枪高度、供氧强度及吹氩强度等参数,可以准确判断VOD吹炼终点,实现真空下"脱碳保铬"的有效控制。     

三峡水轮机叶片用不锈钢的熔炼

一重公司通过对钢包精炼炉进行真空氧脱碳(VOD)改造(安装水冷氧枪和真空加料系统),成功地熔炼并浇铸出碳含量在0.03wt%以下且气体含量很低的三峡水轮机用不锈钢叶片。所制叶片不仅化学成分、冶金质量均达到了设计要求,而且比以往工艺降低生产成本约13%,技术经济效益十分可观。     

VOD冶炼不锈钢碳、铬、硅等元素的氧化规律探讨

本文从6吨 VOD 炉实际冶炼18—8类型不锈锏出发,探索了真空吹氧过程中碳、铬、硅等元素的氧化规律。得出6吨 VOD 炉吹氧过程脱碳反应表现活化能为120Kcal/mol。温度对实际冶炼的影响比之在感应炉中的影响为大。求得小型 VOD 炉冶炼不锈钢时,氧化前期硅氧化的动力学随机模型为:[%Si]_t=0.934[%Si]_0exp(-0.088t)     

钢包炉真空脱碳生产低碳不锈钢

在 HB—50型铜包精炼炉上增设吹氧枪,形成了在真空下吹氧精炼装置(即 VOD),本文概述了本设备与电弧炉联合冶炼不锈钢的工艺操作,真空下精炼过程的控制,成品铜可达到超低碳的要求,18—8型不锈钢铬的回收率波动在86～100%,且只需用高碳铬铁,成品质量明显提高,去氢率在46～69%之间,氮的最终含量在200ppm 以下,含氧量20ppm 以下,钢的无发纹率达99%,成本与电弧炉返回法对比降低199.25元/吨。若与电弧炉冶炼超低碳不锈钢对比,成本降低的幅度更大。     

电弧炉用100%返回料吹氧冶炼0Cr_(18)Ni_9型不锈钢

本文主要介绍根据“温度效应”降碳保铬的原理,在1.5 t电弧炉上采用100%返回料吹氧冶炼0Cr18Ni9型不锈钢铸件的工艺方法,并对主要工艺参数进行了讨论。采用该工艺冶炼的五炉CF8M不锈钢铸件机械性能大大优于规格要求,并且使铬的回收率达到了93～96%的水平。该工艺不需增加任何新设备,在中小型普通电弧炉上少用或不用昂贵的微碳铬铁,用100%返回料吹氧冶炼低碳(C≤0.08%)不锈钢,大幅度降低生产成本。     

CAP1400核主泵泵壳铸件的研发

通过对核主泵泵壳的材料组织与性能控制、泵壳铸造工艺、合金冶炼工艺、凝固过程控制等方面的研究,实现了CAP1400核主泵铸件的开发。结果表明,采用双电炉熔炼—LF精炼—VOD处理的冶炼工艺,能够稳定保证C≤0.08%,铁素体含量8~20%;优化的计算机模拟铸造工艺能够实现铸件内部致密;选取的热处理工艺可以满足核主泵泵壳抗拉强度≥530 MPa,屈服强度≥240 MPa的要求。     

采用VOD工艺冶炼泵壳用钢Z3CN20-09M

详细介绍了用VOD工艺冶炼Z3CN20-09M钢的过程。最终产品的含碳量为0.028%,Cr的回收率达83.5%。     

Effects of non-metallic inclusions on the initiation of pitting corrosion in 11% Cr ferritic stainless steel examined by micro-droplet cell

This paper explores the effects of non-metallic inclusions (NMIs) on the initiation of pitting corrosion in type 409L stainless steels refined by the argon oxygen decarburization (AOD) and vacuum oxygen decarburization (VOD) processes. The dominant NMIs in the AOD and VOD samples were (Ti, Ca)-oxides and Ti-nitrides, respectively. In-situ electrochemical noise (EN) and micro-electrochemical analyses were conducted to investigate quantitatively the inherent effects of the NMIs on the pitting corrosion of the alloys. Pitting corrosion was initiated mostly around the (Ti, Ca)-oxides in the AOD samples, while little such corrosion occurred around the Ti-nitrides in the VOD samples. In addition, the pitting resistance of the AOD samples increased with increasing Ti content and decreasing Ca content in the (Ti, Ca)-oxides.     

采用VOD法冶炼1Mn18Cr18N护环钢

阐述了采用电炉与 VOD双联、真空精炼、大气下注的工艺生产 3 0 0 MW发电机护环用1 Mn1 8Cr1 8N钢的生产过程 ,着重讨论了 VOD原理及高 Mn、高 Cr时 N的溶解度和真空下 Mn的行为 ,以及生产方案的可行性及相应的措施     

Properties of CuCr contact materials with low chromium content and fine particles

1　INTRODUCTIONCuCralloyhastakentheplaceofCuBialloyforitsexcellentelectricpropertiesandhasbeenwidelyusedinmediumvoltage ,highcurrentvacuuminter rupter[1,2 ] .CuandCrhaveverylittlesolubilityineachother .Atroomtemperature ,thesolubilityisapproximatelyzero .Infact,Cu Cralloyisapseudo alloywiththemixtureofCuandCrcomponent .Cu CrcontactmaterialsreservetheexcellentpropertiesofCuandCrcomponent,sothecontactmaterialshaveexcellentelectricproperties.TheoptimalcontentofCrinCuCrcontactmate rialh…     

Oxidation limited life times of chromia forming ferritic steels

Long term, cyclic oxidation studies of three high – Cr, ferritic steels were carried out at 800°C and 900°C in air. It was found that with decreasing sample thickness the life time of the mentioned alloys decreases due to breakaway phenomena. This effect is caused by faster exhaustion of the chromium reservoir from the bulk alloy in case of thinner components. The observed life time limits can be predicted with reasonable accuracy by a theoretical model, using oxide growth rate parameters, initial alloy Cr content and critical Cr content required for protective chromia scale formation. In the calculation it has, however, to be taken into account that the oxidation rates of the steels increase with decreasing specimen thickness.     

Fe-Cr-C系高碳高铬耐磨堆焊合金微观组织分析

研究了C元素含量6.0%左右时改变Cr元素含量和Cr元素含量40%左右时改变C元素含量两种情况下Cr及C元素各自对Fe-Cr-C合金堆焊层组织的影响.结果表明,C和Cr元素增加时,初生碳化物的量增加.初生碳化物随着C元素和Cr元素的增加,形态越来越规则,分布越来越密集,初生碳化物颗粒的单个尺寸增大.C元素含量6.0%左右,Cr元素含量增大时,初生碳化物微区Cr元素含量增加;而当Cr元素含量40%左右,C元素含量增加时,初生碳化物微区Cr元素含量反而降低.     

Effect of tungsten on carbide formation in steel 30KhG

Conclusions Alloying of Cr-Mn steel with tungsten inhibits diffusion processes, due to which the temperature at which elements are redistributed between the matrix and iron carbide increases. Alloyed chromium carbide is formed in the steel with 0.75% W in the process of tempering at 600°C. In the steel with 1% W chromium carbide is formed at 575°C. Hexagonal chromium carbide is formed in these steels due to gradual rebuilding of orthogonal iron carbide. Raising the tungsten content to 1.25% causes substantial enrichment of cementite with tungsten, and at 600°C hexagonal carbide (W, Cr)₂C is formed by the aging mechanism, the tungsten content increasing considerably, and the concentrations of chromium, iron, and manganese decreasing, with increasing temperatures. A larger tungsten content leads to formation of carbide identified as tungsten carbide W₂C.Institute of Problems of Casting, Academy of Sciences of the Ukrainian SSR. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 9–13, June, 1979.     

不锈钢VOD精炼吹氧阶段脱碳保铬的热力学分析

为了保证VOD吹氧阶段高脱碳量和铬的高回收率,以不锈钢ZG06Cr13Ni4Mo为研究对象,采用热力学计算软件FactSage8.1对VOD精炼过程吹氧阶段的供氧量、温度及真空度等参数对钢液中碳、铬含量的影响进行了分析,并在单因素计算的基础上设计了三因素三水平的正交试验,确定了供氧量、温度及真空度对脱碳保铬影响的顺序以及优化参数。结果表明,吹氧阶段供氧量应控制在4.68~6.10 m3/t(标准态)范围内;开吹温度应设置在1 585~1 600 ℃内且停吹温度不应超过1 750 ℃;压强应控制在5~9 kPa。此外,3种因素对吹氧阶段脱碳保铬的影响顺序为供氧量>真空度>温度,优化结果为供氧量4.9 m3/t(标准态)、温度1 600 ℃、压强7 kPa,且在此条件下的碳、铬质量分数分别为0.027%、12.201%。     

汽轮机用钢2Cr11MoVNbN的锻造工艺及锻后热处理工艺

2Cr11MoVNbN钢是目前12%Cr系耐热性能最好的钢种之一,是一种较为理想的亚临界、超临界汽轮机叶片用材料。通过采用VOD炼钢,上平砧,下V型砧拔长下料,多火次,小压下量镦粗工艺,成功锻出2Cr11MoVNbN叶片,质量达到要求。