论文

利用EBSD技术研究了电工钢中长轴平行于轧向的柱状晶样品在热轧和退火过程中组织和取向的演变规律,并与长轴平行于板法向的样品的已有研究结果进行对比。结果表明,无论柱状晶按何种方向排列,只要表面存在剪切力,热轧后都可形成剪切织构,同时中心形成轧制织构,主要包括旋转立方织构和{112}<1-10>。柱状晶造成的影响主要体现在板中心层,长轴平行于轧向排列的样品热轧时形成的粗大旋转立方晶粒要到脱碳退火后才能完全消除,但破坏了正常的不同取向晶粒间的取向差分布及尺寸均匀性,导致二次再结晶不完全及磁性能降低。 The evolution of microstructure and grain orientation in an electrical steel containing columnar grains with its long axis being parallel to the rolling direction of sheet was studied during hot rolling and annealing by EBSD technique.The results are compared with those of samples containing columnar grains being parallel to normal direction of sheet reported in the reference [3].It was shown that,whether the long axis of columnar grains was arranged in RD or ND,shear textures can be formed in t... 

借助高温激光共聚焦显微镜,在线观察了不同Mn含量的无取向硅钢中夹杂物的尺寸、类型、数量变化。结果表明,Mn含量(质量分数)为0.77%、0.32%时,试样中的夹杂物数量分别约为1000万个/mm3、1600万个/mm3。Mn含量较高的钢种,会优先析出球形、椭球形MnS夹杂物,其析出数量较少,尺寸相对较大,可以有效抑制AlN、CuxS夹杂物析出;Mn含量较低的钢种,会在试样再加热后冷却过程中,先析出相当数量MnS夹杂物,并作为AlN夹杂物析出核心,形成MnS+AlN复合夹杂物。这种复合夹杂物数量较多,尺寸也较大。 Based on the high temperature confocal microscope, the chage of size, type, and quantity of inclusions in non-oriented silicon steels with different Mn content were observed by in-situ SEM. Results show that the inclusion quantities are 10 million per mm3 and 16 million per mm3,while the mass fractions of Mn are 0.77% and 0.32%, respectively. In the silicon steel with higher Mn content, the spherical and ellipsoidal MnS inclusion will precipitate first, which can retard the precipitation of AlN ... 

为探究铬、锰元素及退火温度对高强无取向硅钢性能的影响规律,借助OM、SEM、EBSD与万能拉伸试验机等分析不同制造工艺下3组不同含量铬、锰元素的无取向硅钢热轧、常化及退火处理后组织与性能。结果表明,试验钢热轧后组织不均匀,心部为沿轧向分布纤维状组织,边部为少量再结晶晶粒,常化处理能显著改善热轧板组织均匀性,消除热轧板中心部位的纤维状组织。经冷轧及退火后得到多边形铁素体晶粒,其中960℃退火,晶粒尺寸偏大,有利织构{100}组分体积分数减少,不利织构{111}组分体积分数增加,成分为0.2Mn-1Cr的1号试验钢960℃退火后铁损最大,磁感强度偏小;成分为0.5Mn-1Cr的2号试验钢930℃退火后,磁性能与强度等综合性能最佳,工频铁损P_1.5/50为2.41W/kg,高频铁损P_1.0/400为17.36W/kg,磁感应强度B_{5 000}为1.638T,抗拉强度为685MPa。 In order to study the effect of Cr,Mn and annealing temperature on the properties of high-strength non-oriented silicon steel,the microstructure and properties of three groups of non-oriented silicon steel with different Cr,Mn content under different manufacturing processes were analyzed by means of OM,SEM,EBSD and universal tensile tester.The results show that the structure of experimental steel is not uniform after hot rolling,and the core is distributed in fibrous structure along the rolling ... 

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...