冷轧压下率对Hi-B钢初次再结晶织构的影响

研究模拟CSP工艺试制Hi-B钢在不同冷轧压下率(73%、78%、83%、88%及93%)下对其初次再结晶退火(850℃,5 min)后织构的影响。使用Zeiss Axioplan金相显微镜观察组织,借助NOVA400 Nano SEM型场发射扫描电子显微镜进行微观织构EBSD(电子背散射技术)数据采集,利用二次萃取复型法制样并通过JEM-2100透射电子显微镜(TEM)及能谱仪(EDS)观察压下率为88%的初次再结晶样品中抑制剂析出情况。结果表明:Hi-B钢冷轧的最合适压下率约为88%,冷轧初次再结晶退火(850℃,5 min)后晶粒细小,组织良好,有一定的Goss晶粒,有利的{111}112织构含量较高和较多的∑9、∑3、∑5有利CSL晶界。抑制剂(主要为Cu2S)析出较多,平均尺寸大小约为50.15 nm,平均面分布密度约为1.54×109个/cm2。     

MgO涂层对Hi-B钢织构与抑制剂的影响

研究了MgO涂层对Hi-B钢高温退火过程中组织织构与抑制剂的影响。借助磁性能测试仪测试其磁性能,使用金相显微镜(OM)观察试样组织,借助扫描电子显微镜(SEM)和EBSD技术进行抑制剂观察和织构检测,利用投射电子显微镜(TEM)及能谱仪(EDS)进行能谱分析。结果表明:氧化镁涂层能延缓抑制剂粒子的分解,保持较高的粒子分布密度,进而抑制初次再结晶晶粒的粗化,提高二次再结晶的开始温度。另一方面涂层能影响二次再结晶过程。无涂层样品与氢气直接接触,较多接近{110}面织构而与〈001〉晶向偏差较大的晶粒发生了异常长大,导致二次再结晶晶粒数量更多,尺寸更小且Goss织构比较散漫。有涂层样品Goss织构更加锋锐且磁性能更优。     

常化及冷轧压下率对Hi-B钢初次再结晶织构影响

 为了研究Hi-B钢的常化工艺(二段式常化)及不同冷轧压下率(63.8%、75.2%及87.1%)对其初次再结晶退火（820 ℃,5 min）后织构的影响,采用CSP工艺试制以Cu2S和AlN作为抑制剂的方法进行模拟。利用NOVA400 Nano SEM场发射扫描电子显微镜对初次再结晶退火后的微观织构进行EBSD数据采集,从晶粒取向、ODF分析以及特征取向线分析3个方面对织构进行分析。结果表明,经常化后再冷轧初次退火后Hi-B钢的组织更加均匀,高斯织构和有利的{111}〈112〉织构相对较多,织构间发生了转变,对产生高斯织构有利的{111}〈112〉织构为主要转变产物。在压下率为87.1%时,有良好的晶粒取向以及合适的取向线分布。     

无抑制剂取向硅钢概述

概述了无抑制剂法生产取向电工钢的特性及其用途;总结无抑制剂生产取向电工钢的原理及工艺方案.重点讨论了成分方案,即元素对磁性能的影响和最终高温退火方案对二次再结晶的影响.研究结果表明,无抑制剂取向硅钢化学成分范围没有普通取向硅钢和高磁感取向硅钢严格,提高了成材率;最终高温退火决定了二次再结晶的好坏,从而最终决定成品磁性能,最佳的高温退火温度在850～950℃之间.     

低温板坯加热Hi-B钢的组织和织构演变

采用光学显微镜和X射线衍射仪对低温板坯加热Hi-B钢的组织、织构的特征演变进行了研究。结果表明：从热轧板和常化板的表面到中心,组织和织构分布不均匀。热轧板组织分为表层再结晶区域、再结晶和变形晶粒混合区域和中心变形晶粒区域,并且热轧板各层的织构类型不同。常化板表层晶粒长大,过渡层和中心层的形变晶粒基本消失,常化板继承了热轧板的织构特点。冷轧板为纤维状变形组织,冷轧后形成了以{001}<110>～{111}<110>为主的α织构。脱碳渗氮板的横断面和纵断面的晶粒平均尺寸分别为25.9μm和25.3μm,织构主要为{111}<112>、{114}<481>和{001}<120>织构。成品板晶粒平均尺寸为19.1μm,成品板为单一的高斯织构。     

TSCR+固态渗氮工艺试制Hi-B钢的模拟试验

 在实验室模拟TSCR+固态渗氮工艺试制了高磁感取向硅钢。试验结果表明,初始氮质量分数为00034%~0.0084%试验钢,采用MgO涂层中添加MnN的方式进行固态渗氮后钢中氮质量分数为0.0146%~00164%;不经渗氮的脱碳板在试验退火条件下没有发生二次再结晶,渗氮后脱碳板的二次再结晶开始温度约为980℃;二次再结晶前初次晶粒约为23μm,渗氮后在高温退火阶段形成的AlN起到了抑制初次再结晶晶粒长大的作用;试验钢的磁性波动较大;其中最好磁性能B8达到1.928T,P17/50达到1.174W/kg。TSCR +固态渗氮工艺生产高磁感取向硅钢是可行的。     

Hi-B钢连铸坯凝固组织及偏析的研究

通过工业试验,借助低倍检验、化学分析和原位分析等手段,对不同过热度和二冷比水量条件下Hi-B钢铸坯的宏观凝固组织和元素偏析进行分析检测,探究钢水过热度和二冷强度对铸坯凝固组织和元素分布的影响规律.结果表明,提高二冷强度,可使柱状晶率增加,降低过热度,可保留一定数量的等轴晶区.但过热度和二冷强度对铸坯中心等轴晶晶粒尺寸影...     

冷轧IF钢中内应力对再结晶晶粒取向的影响

以主动滑移系统及流动所需的位错为基础计算了保留在变形基体中的残余应力。用新型再结晶模型预测了希望在内应力基体中优先生长的再结晶晶粒的取向。该模型涉及两个原理1）应变能释放极限论和2）{110}面配合生长。将用此种方法获得的预测结果与实验结果相比较，并讨论冷轧产生的内应力对再结晶织构的可能影响。     

晶粒取向硅钢的织构控制

本文介绍晶粒取向硅钢织构控制技术的历史背景和目前的发展状况，重点放在炽构和徽现组织的非均均匀性对{110}〈001〉取向晶粒完美二次再结晶所起的重要作用。晶粒取向硅钢的织构控制涉及到时织构和微观组织中局部非均质的控制：在整个工艺过程中，应完全提供二次再结晶的潜在被心及有利于其生长的基体环境。     

轧后冷却工艺对模拟CSP含铜Hi-B钢热轧组织和结构的影响

以模拟CSP工艺-真空感应炉熔炼含铜Hi-B钢(/%:0.06C,3.38Si,0.14Mn,0.013P,0.003S,0.019Als,0.37Cu,0.0015O,0.0087N)模铸成210mm×120mm×60mm板,Φ350mm二辊热轧机1065℃开轧经5道次从60mm轧成3.5mm板(终轧865℃)为试验基板,研究了轧后水冷和轧后水冷至580℃再空冷两种冷却工艺对实验钢组织和织构的影响。结果表明,热轧后水冷到580℃再空冷到室温的冷却方式有助于获得更高取向精准度的高斯织构、更低比例的黄铜织构以及其他合理的织构组成,较轧后水冷工艺更加适合实验钢。     

Microstructure and texture evolution of high temperature nitriding Hi- B steel during secondary recrystallization

Effects of different annealing temperatures on the microstructure and texture during the secondary recrystallization of Hi- B steel manufactured by simulating CSP process were studied by Zeiss Axioplan optical microscope(OM), NOVA400 Nano field emission scanning electron microscope(SEM) and electron back- scattered diffraction(EBSD). The results show that Goss grains grow abnormally at 1040??, and the grains are fine and uniform before abnormal growth. The {111}??112?? and {411}??148?? textures are the main textures. A small number of grains grow rapidly after abnormal growth, and the Goss texture is the main texture. The distributions of misorientation angle of Goss, {111}??112?? and {411}??148?? orientation are mainly between 20??-45??, the high energy boundary theory (HE) can explain the abnormal growth of the Goss grain. The CSL grain boundary ratio of the matrix is relatively low, the proportion of the ??3 grain boundaries with poor mobility is high, the proportion of the ??5, ??7, ??9 grain boundaries is low, and CSL grain boundary theory is not persuasive for abnormal growth of Goss grains.     

微孔MgO耐火材料对钢液洁净度的影响

通过浸泡实验研究了3种镁质(致密镁质、微孔MgO质、镁碳质)耐火材料与超低碳钢液(1 560℃)的相互作用,考察了不同浸泡时间(0～35 min)钢中O、N、C和Al、Si、Mn含量及钢中夹杂物的成分、数量、分布等特征的变化,并对耐火材料与钢的界面层进行了观测和分析。结果表明,随着浸泡时间的延长,3组钢中氧含量均先升高再降低,均对钢液有一定的污染,钢中夹杂物的数量增加,夹杂物种类由Al₂O₃-MnO夹杂逐渐转变为Al-Mg-Si-Mn-O复合夹杂。与致密镁质耐火材料相比,微孔MgO质和镁碳质耐火材料与钢的界面处分别能形成连续的镁铝尖晶石层和致密的MgO层,有助于降低耐火材料的侵蚀以及对钢液的污染。此外,与不含碳的镁质耐火材料相比,镁碳质耐火材料对钢液增碳严重。因此,微孔MgO质耐火材料不仅对钢液的二次污染小、不会向钢液增碳,而且还可以吸附钢中氧化铝夹杂,更有利于超低碳洁净钢的生产。     

交流杂散电流对剥离涂层下X80钢腐蚀行为研究

交流杂散电流严重威胁埋地管道的腐蚀,尤其是管道涂层出现破损时交流杂散电流的影响更为严重和复杂.为此,采用电化学方法、阵列电极技术(WBE)、扫描电镜(SEM)以及X射线能谱分析(EDS)等研究了不同交流杂散电流密度对剥离涂层下X80管线钢腐蚀行为的影响.结果表明:交流杂散电流对X80钢在土壤模拟溶液中的腐蚀起促进作用,...     

Effect of Nitrogen Content on Primary Recrystallization Behavior and Magnetic Property of Hi-B Steel

The effect of nitrogen content on primary recrystallization microstructure,texture and magnetic property of Hi-B steel was studied by means of optical microscopy(OM),scanning electron microscopy(SEM),and electron backscatter diffraction(EBSD).When nitrogen content increased gradually from 0.005 5% to 0.031 0%,the primary grain size and variation coefficient of nitrided sheet reduced from 26.85μm,0.590 to 18.87μm,0.525-0.565,respectively.Meanwhile,the primary recrystallization texture style of nitrided sheet was nearly identical to the texture style of decarburized sheet before nitriding treatment,but exhibiting a certain change on texture intensity.The variation of average magnetic induction value(B_8)and core loss value(P_(17/50))were manifested to be Mshaped and W-shaped curves,respectively.When nitrogen content reached 0.016 0%,the best value of the average magnetic property of the final product was obtained as follows:the B_8 and P_(17/50) were 1.921 Tand 0.968W/kg,respectively.Meanwhile,the best performance,B_8 and P_(17/50),of single sheet was 1.964 Tand 0.854 W/kg.     

Influence of inhibitors on primary recrystallization structure of Hi- B electrical steel

The influence of different inhibitors on textures after primary recrystallization(830??,5min) of Hi- B steel manufactured by stimulating CSP process was studied by Zeiss Axioplan optical microscope(OM), NOVA400 Nano field emission scanning electron microscope (SEM), electron back- scattered diffraction(EBSD), JEM- 2100 transmission electron microscope (TEM) and energy dispersive spectrometry(EDS) which specimen was made by the second extraction replica method. The results show that the average grain size of sample A is smaller than that of sample B. The inhibitors of sample A and B are mainly Cu2S and AlN, MnS and AlN. Contents of favorable Goss and {110}??112?? texture of sample A are relatively more than that of sample B. The contents of unfavorable texture such as {110}??112?? texture are relatively small. More ??3, ??5 and ??9 CSL grain boundaries occur in the sample A.     

厚壁X80热轧管线钢生产实践及热加工组织演变分析

通过Thermomastor-Z热模拟试验机双道次压缩实验,研究了X80管线钢在880～1 050℃温度区间的静态再结晶行为,结果表明,实验钢在920℃及以下未发生再结晶,在960℃及以上温度,随道次间隔时间延长,静态再结晶率增加。采用不同卷取温度进行了21.4 mm厚度X80板卷工业试制,精轧开轧温度设为920℃,卷取温度510℃的试制钢组织为准多边形铁素体+粒状贝氏体+MA,卷取温度410℃的试制钢组织为粒状贝氏体+贝氏体铁素体+弥散分布的MA的细小组织,后者的MA尺寸和贝氏体板条尺寸明显小于前者,表现出更优异的低温冲击韧性和DWTT性能。通过TEM发现试制钢中的MA是以马氏体为主的组织,并含有较多纳米级尺寸、以Nb元素为主的Nb/Ti碳氮化物复合析出相,但V的析出量则很有限,此外,高卷取温度试制钢的析出相含量也更高。     

Study on dynamic recrystallization behavior of hot rolled TRIP steel produced by CSP process

The dynamic recrystallization behavior of hot rolled TRIP steel produced by CSP process was studied by means of Gleeble-3500 thermal simulation testing machine in the temperature range of 950-1150℃ with the strain rate of 0.1-10s-1 and the strain of 65%. And the effect of initial austenite grain size on the dynamic recrystallization behavior of TRIP steel was explored. The results show that the finer initial austenite grain size, the higher deformation temperature and the lower strain rate, the more positive austenite dynamic recrystallization of TRIP steel. Moreover, it is found that when the coarse grained samples (initial austenite grain size is 767.54μm) deform in the range of 1050℃ to 1150℃, the austenite dynamic recrystallization will take place, and the dynamic recrystallization activation energy of TRIP steel is deduced as 361539.17J/mol. The Zener-Hollomon parameter equation as a function of strain rate and temperature is determined. And the model of critical strain for dynamic recrystallization, the flow stress model of austenite at high temperature and the grain size model for dynamic recrystallization are also established. The calculation results are coincided well with the experimental results.     

取向硅钢中高斯晶粒异常长大选择性行为

对CGO取向硅钢二次再结晶中断实验进行了研究,发现二次再结晶升温过程中,仅在异常长大开始前,高斯晶粒尺寸明显大于其他晶粒,且不同取向晶粒的数量与脱碳退火时的特征一致.高斯晶粒晶界上MnS等抑制剂的优先粗化使高斯晶粒能够率先发生异常长大,且只有晶界弯曲严重或经过很小的生长几个晶粒就能合并的高斯晶粒才能成为二次晶核.在高斯晶粒异常长大过程中,晶界形貌参差不齐,呈岛屿状.研究表明:高斯晶粒独特的生长方式,可能是使二次再结晶能很快完成的原因.