所有分类
  • 所有分类
  • 未分类

考虑剪应变对微孔洞损伤演化的影响,对GTN损伤模型的损伤演化机制进行修正,建立了适用于不同应力三轴度水平的损伤模型。结合隐式应力更新算法和显式有限元计算,采用VUMAT子程序实现了修正GTN模型在有限元软件ABAQUS中的数值计算。通过模拟纯剪切和剪切-拉伸两组试样的损伤演化和断裂行为,验证了修正GTN模型在不同应力三轴度承载条件下的有效性。运用修正GTN损伤模型模拟含边部缺口的带钢在轧制过程中裂纹的萌生和扩展行为,模拟结果与实验相一致,表明该模型可有效地用于带钢缺陷在轧制过程中扩展行为的分析和预测。模拟和实验结果表明,带钢边部缺口在轧制过程中,缺口前沿和后沿均会萌生裂纹,且后沿裂纹扩展更为明显。 Considering the effect of shear strain of micro-void on damage evolution, a modified GTN model applicable to various stress triaxiality conditions is proposed by modifying the damage evolution mechanism of the GTN damage model. The modified model is implemented in commercial finite element software ABAQUS by combining the implicit stress update method with an explicit finite element solving algorithm and through the user-defined material subroutine VUMAT. The damage evolution and the failure pro... 
2014-06-28 149 5.8

采用XRD物相分析、金相组织观察及TEM精细组织分析研究了奥氏体组织结构状态对Fe-0.88C-1.35Si-1.03Cr-0.43Mn钢中温等温相变鼻温和孕育期的影响,以及不同温度奥氏体化后240℃等温20 min试样的组织结构特征。试验发现,随着奥氏体化温度的升高,中温等温开始转变的鼻温移向更低温度并且相变孕育期缩短;不同温度奥氏体化后同为240℃等温20 min处理,虽然均形成由贝氏体铁素体亚条平行排列构成的束状贝氏体组织,但贝氏体组织的精细结构状态不同,突出的差别在于对应低温奥氏体化贝氏体亚条端部边界具有凸起结构,而对应高温奥氏体化贝氏体亚条端部边界较为平齐且呈现楔形结构。不能简单地以马氏体切变机制认识试验钢中贝氏体组织的形成。 The influence of austenitization temperature on the incubation period and the bainitic phase transformation behaviour in high-carbon silicon steel has been investigated using X-ray diffraction(XRD), optical microscopy and transmission electron microscopy(TEM). The microstructure characteristics of the isothermal transformation(240 ℃, 20 min)products were also studied. It was found that the nose temperature of bainite transformation and incubation period decreased with the increasing austenitizin... 
2014-07-28 148 5.8

采用EBSD检测技术,分析了50W800无取向电工钢在重要生产工序间织构的演变以及织构沿带钢宽度方向上的差异性。结果表明:热轧板织构沿带钢宽度方向上的差异性主要体现在表层织构。带钢边部表层织构主要由旋转立方织构、α纤维织构以及少量的γ纤维织构组成,带钢宽度1/4处的表层织构主要存在高斯织构,带钢宽度1/2处的表层织构主要为(110)面织构以及少量的铜型织构。各处的带钢宽度1/4处和1/2处的织构类型基本一致,都以α纤维织构和旋转立方织构为主。冷轧后,各处的表层织构类型差异较小,均为γ纤维织构和α纤维织构。由板宽边部至中心处织构强度值逐渐降低。退火后,各处织构的组分基本一致,为较强的γ纤维织构和较弱的(100)面织构。各处织构强度值差异较小,变化趋势与冷轧板一致。 The texture of non-oriented electrical steel 50W800 was detected by EBSD technique.The evolution of the texture between important processes and the difference of texture along the width direction of strip were analyzed.The result shows that the difference along the width direction of strip of texture at the surface of hot rolled plate is most obvious.The texture at the surface of strip edge is primarily made of rotating cube texture,αfiber texture and weakγfiber texture.Goss texture is mainly co... 
2014-09-28 148 5.8

为提高无取向硅钢导磁性能,研究了不同剪切方式对无取向硅钢剪切处磁畴结构的影响。利用纳米磁流体观测无取向硅钢剪切后边部磁畴结构。结果表明,硅钢无论在机械剪切还是线切割后的边部磁畴都会发生不同程度的改变:线切割对边部磁畴结构改变较小,边部磁畴分布均匀且连续,在距边缘0~20μm范围内出现磁畴宽度变小现象;机械剪切对磁畴的改变较为严重,剪切处磁畴零乱且不连续,在距边缘20μm处仍难以观察到完整的磁畴结构。 The effects of different shearing modes on magnetic domain structure of cold rolled non-oriented silicon steel are studied in this paper.The magnetic domain of cold rolled non-oriented silicon steel is observed by nanometer magnetic fluid pattern method.The results show that the edge magnetic domain structure will be changed by mechanical shear and wire-electrode cutting,the variation of edge magnetic domain structure wire-electrode cutting edge is very small,the magnetic domain structure is wel... 
2012-04-28 148 5.8

【作者】 安斌; ...
2014-09-28 148 5.8

借助于EBSD对比研究了常化退火对高牌号无取向电工钢热轧组织和织构演变的影响,分析了常化退火对热轧板各厚度层织构的演变规律。结果表明,常化退火改善了热轧组织的均匀性,并弱化了热轧变形的γ纤维织构。升高常化退火温度,可增大热轧板的晶粒尺寸,提高{100}和{110}织构组分占有率,有利于提高无取向电工钢成品板的磁性能。 Effects of normalizing annealing on microstructure and texture of high-grade non-oriented electrical steel hot-rolled sheet were investigated by EBSD. Emphasis was put on the effects of normalizing annealing on texture evolution in the sheet thickness. The results show that the hot-rolled microstructure homogeneity is improved and the γ-fiber texture is weakened by normalizing annealing treatment. The grain size of hot-rolled sheet and intensity of the {100} and {110} favorable texture can be in... 
2014-02-28 148 5.8

在15 kg真空感应炉上,用CaO-Al2O3-SiO2-MgO渣系进行脱硫试验,探讨了脱硫渣系碱度、MI、Al2O3、CaF2对脱硫效果的影响。研究结果表明,随脱硫渣系碱度、MI、Al2O3和CaF2含量的增加,脱硫率都呈现先增加后减少的趋势。初始硫含量为0.009 33%~0.010 73%,加入脱硫渣系4 min时间内表观脱硫速率为(0.000 96~0.001 49)%/min,平均脱硫率为81.2%,最高达86.8%。当脱硫渣中w(CaO)=58.15%、w(SiO2)=4.85%、w(Al2O3)=25%、w(MgO)=6%、w(CaF2)=6%,脱硫效果最好,此时钢液中硫为0.001 33%。 Experiments on desulfurization of molten steel using CaO-Al2O3-SiO2-MgO based desulfurization slag was carried out in a 15 kg vacuum induction furnace. The effects of desulfurization slag basicity,MI, Al2O3and CaF2on desulfurization of molten steel were studied. The results show that with the increase of basicity,MI,Al2O3or CaF2in desulfurization slag,the desulfurization rate rises initially and then decreases. In addition,as the initial sulfur content is 0. 009 33% ~ 0. 010 73%,the apparent des... 
2014-02-28 147 5.8

利用DSC、XRD,结合热焓分析对硅钢级氧化镁和二氧化硅的固相反应行为进行了研究。比较了不同二氧化硅原料及混合方法对硅钢级氧化镁反应性的影响,找到了一种更为有效的硅钢级氧化镁反应性的评估方法,克服了传统柠檬酸活性法在比较不同厂家生产的氧化镁的反应性上的局限性。进一步研究了Na2B4O7添加剂、TiO2添加剂对氧化镁和二氧化硅反应行为的影响,结果表明,Na2B4O7添加剂含量的增加对反应有利,而TiO2添加剂对反应有阻碍作用。 The solid-state reaction behavior between silicon-steel grade MgO and SiO2 was investigated by DSC and XRD combined with enthalpimetric analysis.The influence of different kinds of SiO2 and different preparation methods were studied and a specifical measurement that is more reliable was proposed to evaluate reactivity of silicon steel grade MgO.It overcomes the limitation of the traditional citric acid activity(CAA) method,which can not be used to evaluate the reactivity of... 
2014-03-28 147 5.8

通过金相分析和电子背散射衍射技术研究了一种新型含铜无取向电工钢在950℃退火不同时间(3~180s)空冷后的组织和织构取向的演变。结果表明:该钢在退火3s时的主要织构为α和γ线织构,{100}<110>织构最强;退火20s时织构以<111><112>、{111}<110>、{112}<110>、高斯织构和立方织构为主,随着退火时间的延长,高斯织构和立方织构强度呈减弱趋势;合理控制保温时间有利于提高{100}、{110}面织构的占有率。 Evolution of microstructure and texture oriented of a new non-oriented electrical steel during annealing at 950℃for different times(3-180) s and air cooling was studied by metallography and electron back-scattering diffraction analysis.The results show that after annealing for 3 s most of the texture oriented alongα-fibre andγ-fibre,the intensity of {100}〈110〉was the strongest.{111}〈112〉,{111}〈110〉,{112}〈110〉,Gauss texture and cube texture were the main texture after annealing for 20 s,with the ... 
2011-09-28 147 5.8

以一种新的Fe-Si合金制备工艺为出发点,研究了不同放电等离子体快速烧结工艺(SPS)和Si含量变化对Fe-Si合金材料显微组织与磁性能的影响。结果表明,在烧结温度为1 000℃时制备的Fe-6.5%Si合金(质量分数,下同)的综合磁性能较好,其在50Hz下的铁损为0.549W/kg,最大磁感应强度为0.124 3T,矫顽力245.6 A/m,磁导率0.338mH/m。另外,材料的最大磁感应强度随Si含量的增加显著增长,1 000Hz下,Fe-10.0%Si的最大磁感应强度可达到Fe-6.5%Si合金的5倍左右。 The effects of Si content and SPS technology on microstructure and magnetic properties of Fe-Si alloy material were studied in the paper.It shows that the magnetic properties are the best when the content of Si is 6.5wt% and the sintering temperature is 1 000℃,the iron loss is 0.549W / kg in 50Hz,maximum magnetic induction is 0.124 3T,coercive force is 245.6A / m and permeability is 0.338mH / m。And,the maximum magnetic induction increases significantly with the increase of Si.The maximum magneti... 
2013-04-28 147 5.8

【摘要】 <正>3月15日,随着第5754卷HiB钢下线,武钢...
2011-02-28 147 5.8

本文以热轧常化板为初始材料,采用二次冷轧法与三次冷轧法制备了0.1 mm厚的取向硅钢薄带,测定相应的磁性能,并通过EBSD取向成像技术检测了二次冷轧法与三次冷轧法各工艺过程中织构与组织演变规律。结果表明,采用最终冷轧压下率适中的三次冷轧法,能在冷轧至0.1 mm时保存较多的高斯晶核,使得高温退火后的磁性能明显优于二次冷轧法。最终冷轧压下率通过影响脱碳退火后样品中的{111}<112>织构组分及Goss晶粒数量对最终二次再结晶产生重要影响。 Grain-oriented silicon steel sheets with a thickness of 0. 1 mm were produced from hot-rolled and normalized sheets by two-step-rolling and three-step-rolling methods. Their magnetic properties were measured,and the textures were detected by EBSD technique. The results show that the three-step-rolling method,which has a moderate reduction rate of final cold rolling,can maintain more { 110} < 001 >nucleus,and thus obtaining better magnetic properties compared with the two-step-method. The f... 
2013-04-28 147 5.8

站点公告

网站试运行,请大家关注本站公众号,多提宝贵意见!

显示验证码
没有账号?注册  忘记密码?