共查询到19条相似文献,搜索用时 140 毫秒
1.
2.
3.
4.
为了减少RH真空冶炼过程中钢水锰元素偏差和提高最终产品性能的稳定性,采用直读光谱仪对不同条件下RH真空冶炼镇静钢与非镇静钢锰损情况开展研究。结果表明,RH真空冶炼过程中锰损存在4种形式,与钢水中自由氧反应烧损、钢渣界面反应、合金粉末抽吸、真空锰挥发;随着钢水中锰含量增加、真空时间延长,钢水温度和氧化性提高,RH真空锰损逐渐增加;真空度小于1 000 Pa时,RH真空锰损随真空度的降低而降低,而当真空度大于1 000 Pa时,继续降低真空度,RH真空锰损几乎不变。通过降低RH真空度、进站锰含量和温度、减少RH真空处理时间等措施,RH结束目标锰的质量分数±0.01%命中率接近100%。 相似文献
5.
RH精炼过程加铝前IF钢(/%:≤0.005C,≤0.04Si,0.05~0.20Mn,≤0.015P,≤0.015S,0.03~0.06Als)中的氧含量为340×10-6~467×10-6,用Aspex扫描电镜研究了加铝后210 min钢中夹杂物类型、尺寸和数量,结果表明,IF钢在RH工序加铝脱氧后钢液中夹杂物的类型主要为氧化铝,随着RH循环时间的增加,钢液中夹杂物数量减少;加铝真空循环6 min后可进行合金化,进一步延长循环时间,钢液中夹杂物的去除速度减缓;加铝前IF钢液中的初始氧含量偏高时,可适当延长循环时间至8 min,再进行合金化。 相似文献
6.
IF钢碳含量不稳定因素分析 总被引:1,自引:0,他引:1
针对攀钢IF钢RH处理过程终点碳含量偏高及不稳定的问题,对IF钢生产工艺过程进行了跟踪调查.结果表明:RH处理前钢水[C]及a[O]、真空度、脱碳时间、钢包耐火材料及合金增碳等是影响IF钢碳含量偏高及不稳定的主要因素.RH进站[C]含量高于0.045%,终点碳含量与进站碳含量成正比关系;最小真空度越低,脱碳时间越长,终点碳含量就越低.为保证攀钢IF钢碳含量合格,应将RH进站钢水碳含量控制在0.030%~0.045%、a[O]控制在(500~700)×10-6,加强设备监控与维护以维持足够的深真空时间和进一步降低真空度.为减少RH处理后期钢液增碳,在保证真空室不结冷钢的前提下应使用渣线部位不含碳的钢包及低碳合金. 相似文献
7.
8.
9.
据日本“材料”,1990,3:1180报道为适应厚板优质化和超低碳钢产量的不断增加,要求高精度的RH处理,但是,传统的RH设备一直存在着由于真空室内壁粘附残钢,而导致脱气处理能力降低和钢液增碳等问题。本次开发的是将富氧烧咀应用于在线操作,对清除真空室内壁的残钢取得了显著的效果。就其效果叙述如下。 相似文献
10.
RH真空精炼过程的动态模拟 总被引:2,自引:0,他引:2
建立了描述RH真空精炼装置内钢液动态脱碳(脱气)模型。对RH真空精炼时的脱碳、脱氧、脱氮和脱氢过程进行了动态模拟研究,考察了浸渍管直径、循环流量、吹氩量、氧含量和真空度对脱碳和脱气过程的影响。动态脱碳(脱气)模型考虑了反应机理,认为脱碳是通过上升管中Ar气泡表面、真空室中钢液的自由表面和真空室钢液内部脱碳反应生成的CO气泡表面进行的,并且考虑了精炼处理时的抽真空制度。该模型能全面描述RH精炼过程中不同时刻钢液中碳、氧、氮和氢的含量,能较好预测实际过程,可用于RH真空精炼过程的优化和新工艺开发。 相似文献
11.
12.
介绍了芜湖新兴铸管有限责任公司炼钢厂采用RH-LF精炼法生产低碳钢QD08的工艺实践。通过对转炉出站钢水初始条件,RH真空脱碳原理和过程控制,后续LF冶炼3个方面的分析研究,结果表明,初始钢水控制条件为[C] 0.04%~0.10%,[0]>300×10-6,转炉终点出钢温度T≥1 650℃。随真空处理时间延长,真空度降低,真空室内PCO减少,碳氧浓度积呈降低的趋势,真空室内因发生碳氧反应进行脱碳,RH真空脱碳满足热力学条件;脱碳速率的变化规律为先增大后减小,脱碳速率有一定的规律;RH真空处理后的钢水需在LF完成脱硫、升温、合金化等操作,并且需保证终渣量20~23 kg/t,终渣(FeO)+(MnO)<1.2%,碱度R≥3.5等工艺条件。 相似文献
13.
钢液真空循环脱气法(RH)精炼能够利用高真空和钢液循环流动有效脱气和去除夹杂物。同时,炼钢环境下 CO2可与钢液中[C]反应生成CO提高搅拌强度。因此,本文提出将CO2作为RH提升气进行真空精炼。针对CO2在RH精炼过程的冶金反应行为特性,通过热力学理论分析了极限真空条件下CO2脱碳的有利条件及限度,同时搭建了CO2作RH提升气工业试验平台,通过工业试验对比研究了CO2/Ar分别作提升气时对钢液精炼过程的影响。结果表明,若单纯考虑CO2与碳反应,则当钢液中[C]低于1.8×10?6,CO2仍然具有氧化碳元素的能力。然而,CO2对钢液中碳铝元素存在选择性氧化,当铝含量低于一定程度时,CO2主要参与脱碳反应;反之,CO2则会造成一定铝损,因此若采用新工艺需考虑铝合金加入时机以及加入量。此外,CO2用作RH提升气可获得与Ar效果相当甚至更优的脱氢效果,喷吹同等量CO2并未造成钢液的大幅温降,因此CO2完全有潜力作为RH提升气,进而完成精炼。 相似文献
14.
15.
A mathematical model was developed to predict the carbon concentration during RH refining process. Three reaction sites such as the free surface, inner sites of the molten steel in vacuum chamber, and the bubble surface were considered. The decarburization at inner sites of the molten steel in vacuum chamber was dominant at the initial stage, and then subsequently, it was dominated by the free surface and bubble surface. The decarburization rate constant was also evaluated. 相似文献
16.
17.
18.
19.
A novel three‐dimensional mathematical model proposed and developed for the non‐equilibrium decarburization process during the vacuum circulation (RH) refining of molten steel has been applied to the refining process of molten steel in a 90‐t multifunction RH degasser. The decarburization processes of molten steel in the degasser under the conditions of RH and RH‐KTB operations have been modelled and analysed, respectively, using the model. The results demonstrate that the changes in the carbon and oxygen contents of liquid steel with the treatment time during the RH and RH‐KTB refining processes can be precisely modelled and predicted by use of the model. The distribution patterns of the carbon and oxygen concentrations in the steel are governed by the flow characteristics of molten steel in the whole degasser. When the initial carbon concentration in the steel is higher than 400 · 10−4 mass%, the top oxygen blowing (KTB) operation can supply the oxygen lacking for the decarburization process, and accelerate the carbon removal, thus reaching a specified carbon level in a shorter time. Moreover, a lower oxygen content is attained at the decarburization endpoint. The average contributions at the up‐snorkel zone, the bath bulk and the free surface with the droplets in the vacuum vessel in the refining process are about 11, 46 and 42% of the overall amount of decarburization, respectively. The decarburization roles at the gas bubble‐molten steel interface in the up‐snorkel and the droplets in the vacuum vessel should not be ignored for the RH and RH‐KTB refining processes. For the refining process in the 90‐t RH degasser, a better efficiency of decarburization can be obtained using an argon blow rate of 417 I(STP)/min, and a further increase in the argon blowing rate cannot obviously improve the effectiveness in the RH refining process of molten steel under the conditions of the present work. 相似文献