硅钢脱碳工艺研究

通过对硅钢退火原理的分析，研究了影响硅钢退火的因素，指出调整炉内气氛，改进脱碳工艺，可以达到提高产品质量的目的。     

取向硅钢硅酸镁底层质量的影响因素

取向硅钢在高温退火过程中，涂覆在钢带表面的氧化镁与钢带表面的氧化膜起化学反应，形成致密的硅酸镁玻璃质底层，该底层的质量与硅钢带成品的磁特性和外观质量存在密切的关系。分析了材料化学成分、钢带表面氧化膜、氧化镁的纯度和水化率、涂层添加剂、涂布质量、高温退火工艺等因素对硅酸镁底层质量的影响，并提出了相应的质量控制要素。     

脱碳退火工艺对含铌Hi-B钢组织与织构的影响

借助红外碳硫分析及EBSD技术,研究了含铌Hi-B钢在不同脱碳退火工艺处理后的碳含量及织构变化。结果表明,当炉内气氛和露点温度一定时,含铌Hi-B钢中碳含量随着脱碳温度的升高而下降,随着保温时间的延长先下降,180s以后基本稳定;经850℃×180s工艺退火后钢样的脱碳效果最佳,钢中碳含量为0.0037%。退火试样中均主要含有{411}148、{111}112和{111}110织构组分,少量的Goss晶粒零散地分布在{111}112或{411}148晶粒之间。此外,有利于Goss晶粒异常长大的Σ9及Σ13b晶界的数量,随着脱碳保温时间的延长大致呈增加的趋势,随着脱碳温度的升高先增加后减少,即在840℃退火后出现极大值。     

无取向硅钢晶粒与晶界特征的EBSD分析

借助电子背散射衍射(EBSD)技术测量和计算了无取向硅钢再结晶退火后再结晶百分比、晶粒尺寸、取向差分布等参数,分析了再结晶退火温度对无取向硅钢晶粒大小、微观取向和耐蚀性的影响.结果表明,3个温度(810、840、880 ℃)下退火3 min后,再结晶均充分完成.随着退火温度的升高,再结晶晶粒尺寸长大.拥有{100}面织构的晶粒比其他取向晶粒具有更好的耐蚀性,侵蚀后晶粒凸出于试样表面.880 ℃退火后的小尺寸晶粒周围多为小角度晶界,不易迁移,不易被侵蚀.     

热处理参数对异步轧制硅钢极薄带三次再结晶的影响

采用常规和异步轧制分别将0 3mm厚的成品取向硅钢板冷轧到0 10mm以下,然后在不同气氛的热处理炉中进行三次再结晶高温退火,研究同步、异步轧制条件下,热处理工艺参数(退火温度、保温时间、退火气氛、升温速度)对取向硅钢极薄带的磁性能和三次再结晶行为的影响·结果表明,相同的工艺参数下,真空退火的硅钢极薄带的磁性能优于氢气处理的;退火温度越高,保温时间越长,升温速度越快,磁性能越好,三次再结晶发展得越完善·     

电机铁心用无取向硅钢的退火与发蓝工艺研究

以某变频压缩机电机铁心用无取向硅钢为研究对象,分别采用纯N2气氛去应力退火和DX气氛去应力退火+发蓝工艺对材料进行热处理,退火工艺均为780℃均热2 h.采用SEM、EDAX、XRD等手段表征了热处理后硅钢片表面涂层及氧化层的形貌和组成,用GDS分析了试样表层沿厚度方向的C浓度分布,并测试了其磁性能.结果表明,纯N2气...     

黄铜光亮退火工艺的研究与探讨

待处理工件的成分影响光亮退火工艺的选择,主要探讨有很高表面光洁度要求的黄铜材质工件在去应力退火时光亮退火工艺的使用,对黄铜光亮退火的保护气氛、退火温度等作了分析,实验表明退火后的原料表面光亮度好,机械性能和晶粒度均匀。     

浅谈高碳铬轴承钢的热处理

高碳铬轴承钢在热处理时对碳化物、脱碳程度等项要求严格。所以钢锭在加热时要注意碳化物高温扩散及脱碳问题,为保证碳化物扩散,采用高温扩散退火以减少偏析级别,但为了降低脱碳应适当降低加热温度和缩短在高温带的停留时间;钢坯成材轧后快速冷却,以避免网状碳化物的形成,以利于后续的球化退火,满足切削加工及冷加工的要求。     

冷轧硅钢涂氧化镁产生双线条缺陷的机理研究

分析了冷轧普通取向硅钢中间退火机组在涂层冷轧普通取向硅钢工艺过程中在带钢表面出现宽窄、数量不等的双线条（沿轧向）的机理和影响因素,并结合现有生产工艺条件,提出减少直至消除双线条缺陷的措施。     

脉冲磁场退火对取向硅钢磁性能的影响

通过对取向硅钢进行脉冲磁场退火实验,发现在相同的退火时间（6.0 min）内,低于1 T的脉冲磁场可以在一定程度上提高取向硅钢的磁感（B8）,而高于1 T的脉冲磁场则会使取向硅钢的磁性能急剧恶化.同时发现,脉冲直流电加热方式会使取向硅钢的磁性能恶化.研究表明,脉冲磁场退火有望成为一种调控材料微观结构的有效手段.     

Modeling decarburization kinetics of grain-oriented silicon steel

A mathematic model has been presented to predict the decarburization kinetics of grain-oriented silicon steel sheet in the gas mixture of N2–H2–H2O during annealing.This model is based on the carbon flux balance between the oxidation reaction at the surface and the carbon diffusion inside the steel sheet.It can be numerically solved to quantify the influences of annealing temperature and atmosphere on decarburization kinetics when the boundary conditions are properly determined.In case that a humid gas mixture is employed during annealing,the most influential process parameter is temperature rather than compositions of the gas mixture,because the diffusion of carbon in ferrite is the rate-limiting step.Therefore,a higher temperature is required for the efficient decarburization of the thicker silicon steel sheet using the industrial continuous annealing production line.     

对45号钢冷轧薄钢板脱碳层超标的改进措施

简述了优质碳素结构钢的脱碳机理,以及影响钢脱碳的主要因素——加热温度、加热时间、炉内气氛,分析了实际生产中造成脱碳的原因,提出在现有的条件下,解决45号钢脱碳问题最经济、简单、实用的方法是在退火炉内适当增设木炭或木块,以调节和控制炉内气氛。     

Effect of decarburization annealing temperature and time on the carbon content,microstructure, and texture of grain-oriented pure iron

In this study, the effect of decarburization annealing temperature and time on the carbon content, microstructure, and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However, when the annealing temperature was increased to 825℃ and 850℃, the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time, the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further, the average grain size dramatically increased and the number of fine grains decreased; meanwhile, some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same:{001}<110> and {112~115}<110>, with a γ-fiber texture. Furthermore, little change was observed in the texture. Compared with the experimental sheets, the texture of the cold-rolled sheet was very scattered. The best average magnetic induction (B₈₀₀) among the final products was 1.946 T.     

A process model for BOF process based on bath mixing degree

The process model for BOF process can be applied to predict the liquid steel composition and bath temperature during the whole steelmaking process. On the basis of the traditional three-stage decarburization theory, the concept of mixing degree was put forward, which was used to indicate the effect of oxygen jet on decarburization. Furthermore, a more practical process model for BOF steelmaking was developed by analyzing the effect of silicon, manganese, oxygen injection rate, oxygen lance height, and bath temperature on decarburization. Process verification and end-point verification for the process model have been carried out, and the verification results show that the prediction accuracy of carbon content reaches 82.6% (the range of carbon content at the end-point is less than 0.1wt%) and 85.7% (the range of carbon content at end-point is 0.1wt%–0.7wt%) when the absolute error is less than 0.02wt% and 0.05wt%, respectively.     

RH冶炼超低碳钢内部脱碳机理及控制工艺

为了研究RH真空处理过程脱碳反应速率及其影响因素,并有效地控制超低碳钢在RH真空处理过程中碳含量的变化,根据热力学、动力学原理建立了RH真空处理脱碳数学模型,通过RH真空处理脱碳数学模型研究了内部脱碳反应深度和脱碳速率之间的关系.模型计算结果表明,反应深度的变化和内部脱碳的反应速率是相对应的,采取预真空操作,提升了反应深度,淡化了前期脱碳转折点的影响,加速了前期的脱碳反应,并在RH处理后期找到了内部脱碳向表面脱碳转变的时间临界点.     

冷轧双相钢不停炉连续退火生产工艺改进

不停炉生产冷轧双相钢是控制成本、提高合同交付率的关键技术。对某钢厂连续退火机组生产双相钢前必须停炉的方法进行了分析和改进,结果表明,连续退火机组TV值越小,过时效段降温速度越快;降低快冷段出口温度可显著地降低过时效温度。通过对生产组织的优化,实现了不停炉生产冷轧双相钢。     

Decarburization rate of RH refining for ultra low carbon steel

The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operating conditions. According to the apparent decarburization rate constant (K_C) calculated by the carbon content in the samples taken from the hot melt in a ladle at an interval of 1–2 min, it is observed that the total decarburization reaction period in RH can be divided into the quick decarburization period and the stagnant decarburization period, which is quite different from the traditional one with three stages. In this study, the average apparent decarburization rate constant during the quick decarburization period is 0.306 min-1, and that of the stagnant period is 0.072 min-1. Increasing the initial carbon content and enhancing the exhausting capacity can increase the apparent decarburization rate constant in the quick decarburization period. The decarburization reaction comes into the stagnant decarburization period when the carbon content in molten steel is less than 14×10-6 after 10 min of decarburization.     

铜带可控气氛连续热处理炉断带问题研究与优化

退火是铜带热处理中的重要手段之一,气垫式退火炉是连续热处理的新技术,其应用不仅提高了带材的表面品质,而且强化了铜板带组织性能的均匀性.在对可控气氛连续热处理退火炉的主要组成部分、运行原理及生产中遇到的问题进行梳理的同时,结合多品种合金带材的退火案例,重点分析了铜带退火过程中容易产生断带的几大因素,并提出了相对应的改进方案,通过实践措施和实际应用,形成了可以借鉴的初步结论.     

中温含铜取向硅钢的形变和再结晶织构特征

通过对比中温含铜取向硅钢与普通取向硅钢和高磁感取向硅钢的组织和织构特征,分析中温含铜取向硅钢独特的织构演变规律及其对二次再结晶行为的影响。结果表明,为了获得有利于高斯晶粒长大的强γ取向线织构,中温含铜钢需经过回复退火处理和高温退火阶段慢速升温。回复过程中γ取向线晶粒储能降低,同时慢速升温有利于γ取向线晶粒的形核和再结晶。中温含铜钢的二次再结晶开始温度超过1000益,由于初次再结晶晶粒组织以γ织构为主且非γ取向线晶粒较少,导致最终二次晶粒尺寸超大且晶界圆滑,二次再结晶机理以择优长大为主导,超大的二次晶粒尺寸导致最终成品的铁损升高,但通过激光刻痕处理后,整体铁损的降低效果比二次晶粒较小的高磁感取向硅钢更加显著。     

铝膜沉积温度对非晶硅薄膜晶化的影响

采用磁控溅射(Magnetron Sputtering,MS)方法,研究了不同的退火温度及铝的沉积温度对非晶硅薄膜晶化的影响.通过扫描电子显微镜(SEM)对不同温度沉积的铝薄膜表面结构及形貌进行了分析;并利用光学显微镜,拉曼散射仪(RAMAN)对退火后的薄膜表面形态和结构进行了分析.实验结果表明:适当温度退火可以有效提高对非晶硅的诱导作用,提高铝膜的沉积温度对于非晶硅薄膜晶化有促进作用;在650℃的退火温度下增加铝的沉积温度可显著提高非晶硅的晶化效果.