Effect of heavy cryo-rolling on the evolution of microstructure and texture during annealing of equiatomic CoCrFeMnNi high entropy alloy

The effect of cryo-rolling on the evolution of microstructure and texture during annealing was investigated in equiatomic CoCrFeMnNi high entropy alloy. For this purpose the alloy was cold- and cryo-rolled to 90% reduction in thickness followed by annealing at temperatures ranging from 700 °C to 1200 °C. The two alloys showed the development of predominantly brass type deformation texture consistent with profuse nano-twin formation reported in this alloy. The cryo-rolled material showed significantly finer grain size after different annealing treatments as compared to the cold-rolled alloy. This could be attributed to finer microstructure in the cryo-rolled material providing greater number of available sites for nucleation. The recrystallization texture of cold- and cryo-rolled materials showed the presence of similar texture components indicating that cryo-rolling had limited effect on the formation of annealing texture. The volume fractions of different texture components did not reveal significant dependence on the annealing temperature. The evolution of texture could be explained on the basis of absence of strong preferential nucleation and growth during annealing.     

390MPa级超低碳BH钢织构演变规律

采用ODF织构分析方法,对390 MPa级超低碳BH钢板热轧、冷轧、退火过程织构演变规律进行研究,并对不同冷轧压下量和不同退火工艺织构进行分析。结果表明:经冷轧变形后的钢板有较强的择优取向,具有典型的{112}<110>和{111}<110>织构,形变织构中的不利织构{001}<110>较强;冷轧压下率为80%时再结晶退火后钢板具有较强的γ织构,{111}<112>织构取向密度高达11.7;退火温度和保温时间对α织构影响不大,提高退火温度和延长保温时间使γ织构增强,r值增加。     

Φ508mm×9.5mm L450MB钢级ERW管线管的试制

焊缝冲击功低且不稳定是ERW管线管生产的一大技术难点。针对高钢级L450MB焊管存在焊缝冲击功不稳定的情况,宝山钢铁股份有限公司宝钢分公司钢管厂采取降低焊接速度、调整热处理工艺的技术方案,试制出焊缝冲击韧性符合标准要求的L450MB钢级ERW管线管。     

ERW焊接J55石油套管用热轧带钢的研制

采用C-Mn-Nb-Ti微合金化成分设计、低P、低S高纯净度铸坯冶炼以及合理的控轧控冷工艺,充分发挥细晶强化和析出强化作用,在内蒙古包钢稀土钢板材有限责任公司2 250 mm生产线上成功试制了J55石油套管用热轧带钢,用该热轧带钢制成的ERW焊管具有高强度、高韧性、抗粘扣的良好力学性能,且探伤合格率不小于99%。     

Texture transformations upon annealing of aluminum foils: I. Strong texture components

Pole figures have been constructed and textures have been compared for aluminum foils from various manufacturers in the as-delivered state and after additional annealings. Difference in the orientations of the basic texture components have been revealed in annealed foils. The main type of the transformation of a texture upon annealing is the development of a texture component {001}〈100〉 whose orientation differs fundamentally from the basic texture components observed in the foil prior to annealing. In another type of texture transformations, new texture components close to the basic orientations of the deformation texture are developed along with the {001}〈100〉 orientation. In the case of a third type of texture transformations, along with the orientation {001}〈100〉 which is formed upon recrystallization, the major part of the basic deformation-texture components are retained. The orientations of the basic texture components that are formed upon annealing belong to fields of allowed orientations of the basic texture components that were present in the foil before annealing. Apart from regions with a high pole density, regions with a moderate pole density have been found in the pole figures of annealed foils.     

退火温度对双相纤维复合Cu-12%Ag合金织构的影响

采用强拉拔应变制备了双相纤维复合Cu-12%Ag(质量分数)合金线材,并在不同温度下退火,研究了退火温度对该合金两相中晶体织构强度和分布的影响.随着退火温度升高到400℃,Cu相中(111)织构强度降低而〈100〉强度上升,Ag相中〈111〉强度变化不明显;退火温度高于400℃后,两相中的织构强度均有所增加.在较低的退火温度下,应变形成的Ag相织构稳定性高于Cu相.在退火过程中,相界面迁移,复合组织的聚集、纤维相的球化及等轴晶粒的粗化等仅导致形变织构分量相对强度的变化而形成退火织构,因而退火织构的组成与形变织构的组成相同.     

Cross-rolling and annealing textures in high-purity iron

The deformation and annealing textures of cross-rolled high-purity iron specimens were determined by use of an X-ray Geiger counter spectrometer. The deformation texture was predominantly (100) [011], plus minor texture components of the (111) [1&#x0304;10] or the (111) [112&#x0304;] type. In a partially recrystallized specimen, the minor deformation texture components were replaced by new orientations, while the (100) [011] main deformation texture was retained. A rather complex and widely scattered texture was developed in the completely recrystallized specimen. This recrystallization texture could be derived from the deformation texture components by rotations around (110) poles. The difference in the tendency for recrystallization among different deformation texture components may serve as an important factor in the formation of annealing textures.     

接合面氧化物夹杂对高频电阻焊管韧性的影响

针对四种高频直接缝电阻焊管，通过对焊接接头组织性能的详细分析，表明接合面的夹杂物是恶化焊接接头韧性，特别是低温韧性的主要因素。另外，通过对高频电阻焊管工艺的讨论，指出选择纯净的母材，适宜的焊接工艺及规范参数等能显著减少焊接接合面的夹杂物，获得高韧韧性焊管。     

热轧组织对冷轧无取向硅钢退火织构及组织的影响

对不同加热温度处理的热轧低硅钢带进行了冷轧及退火实验,分析了热轧钢带的组织对冷轧无取向硅钢再结晶退火过程中的组织及织构的影响。结果表明:热轧组织对冷轧无取向电工钢冷轧板再结晶组织及织构演变有重要影响;等轴晶粒组织的热轧钢带比混晶组织的热轧钢带冷轧后再结晶退火快,且退火后晶粒尺寸均匀;随着等轴晶粒尺寸增加,冷轧退火后形成的冷轧硅钢{110}类型的织构增强,{100}类型的织构减弱;表明热轧组织为等轴晶粒时,不利于冷轧无取向硅钢磁性能的改善。     

Large strain deformation of Ni3Al+B: Part II. Microstructure and texture evolution during recrystallization

The microstructure evolution and texture development of the intermetallic compound Ni₇₆Al₂₄, doped with minor additions of boron, was investigated during annealing subsequent to cold-rolling. Upon annealing of cold-rolled specimens, a hardness increase prior to recrystallization was observed. This is attributed to a relaxation process of the dislocation cores during annealing. Recrystallization proceeded with very different kinetics locally and a very small recrystallized grain size was obtained. From grain growth kinetics, the activation energy for grain boundary motion was found to be close to the activation energy for self-diffusion of Ni in Ni₃Al. The recrystallization texture was almost random. However, three texture components could be invariably recognized ({013}100, {012}021 and {112}294). They are related by special orientation relationships to the brass rolling orientation. A high frequency of annealing twins occurred in the recrystallized microstructure. The misorientation distribution function (MODF) shows a preference of certain low Σ boundaries, namely small-angle boundaries (Σ1) and twins (Σ3).     

Process technology for the continuous hot band annealing of 17%Cr ferritic stainless steel

As an alternative to time- and energy-consuming batch annealing, process technology for the continuous hot band annealing of 17%Cr ferritic stainless steel has been established. Process parameters (i.e., temperature and time) for the hot band annealing were optimized in the laboratory and, subsequently, plant trials were conducted. The impact toughness value of the annealed hot band was found to be the most crucial parameter to assess the cold rollability in the commercial run. When the hot bands were continuously annealed at 900 °C, the improved impact toughness values resulted in successful cold rolling to the desired thickness. The impact toughness value and subsequent cold rollability were found to be related to the formation of martensite volume%. Annealing the hot band in the lower temperature range of the two-phase (α+r) region (i.e., 900 °C) yielded the best result. Improvement in roping index has been reported as a result of the weakening of the texture of the continuous-annealed hot band.     

Texture evolution of extruded AZ31 magnesium alloy sheets

The evolution of texture during the annealing and hot rolling process of extruded AZ31 magnesium alloy sheets was studied. There are two kinds of texture components in the extruded AZ31 sheets. One is {0002}<1-010> and the other is {1-010}<1-120>. The {0002}<1-010>component predominates. After annealing at 723 K for 3 h, both {0002}<1-010> and {1-010}<1-120> components are strengthened moderately. This indicates that grains with both two components mentioned above grow faster than those with other orientations. The {1-010}<1-120> component disappears and the intensity of {0002}<1-010> component decreases significantly after hot rolling with a 30% reduction at 623 K. This is mainly attributed to rotational dynamic recrystallization (RDX) during the hot rolling.     

改善球墨铸铁齿轮箱体低温韧性的生产工艺

介绍了有低温冲击要求的和谐D2C型7 200 kW电力机车用球铁齿轮箱体的熔炼、铸造和热处理工艺设计。通过工艺试验和试生产,确定了能够稳定获得合格铸件的工艺方案是:感应炉熔炼+喂丝球化处理+亚温退火处理。采用这一工艺生产的齿轮箱体的低温韧性达到了欧标要求,-40℃的冲击韧度≥15 J/cm2,工艺出品率≥85%,废品率≤3%。试验和批量生产实践表明,较低的退火温度更有利于获得高的低温韧性。     

高磁感取向硅钢的脱碳退火工艺

采用自主研发的热处理试验装置,完成高磁感取向硅钢27QG090实验室脱碳退火过程,利用蔡司显微镜和X射线衍射仪分析脱碳退火后试样的显微组织和宏观织构。结果表明,高磁感取向硅钢27QG090经实验室脱碳退火后的显微组织类型为铁素体,平均晶粒尺寸为30～40μm。宏观织构主要类型为α织构和α^*织构({114}〈481〉、{113}〈361〉等织构),还有微弱的高斯织构{110}〈001〉。经实验室研究选定的最优工艺为850℃脱碳退火7 min。采用该工艺在工业生产线脱碳退火后的宏观织构与实验室脱碳退火后主要织构类型相同。脱碳退火后平均晶粒尺寸为30μm左右时,铁损最低,为0.80 W/kg,磁感应强度可达到1.93 T。     

不同退火工艺对H13钢组织和力学性能的影响

用OM、SEM研究了亚温退火、等温退火、缓慢冷却退火3种工艺对H13钢组织和力学性能的影响。结果表明,亚温退火后碳化物粒度最小,缓慢冷却退火后碳化物粒度较大,退火硬度较低;等温退火及缓慢冷却退火对提高碳化物尺寸、分布均匀性有一定作用,同时碳化物均匀性的提高对提升H13钢退火态及淬、回火态冲击韧性有一定作用,但组织中夹杂物、一次碳化物制约着H13钢韧性的提高。     

铁硅合金轧制-退火过程中立方取向晶粒的形核与长大

利用金相显微镜和EBSD技术分析研究了Fe-3.2%Si合金二次冷轧织构、(100)[001]立方取向晶粒形核、初次再结晶以及二次再结晶后立方织构的形成。结果表明,二次冷轧之后的织构主要为{111}<112>和{111}<011>,并存在少量的{112}<110>,同时在变形晶粒内部存在有接近{100}<001>取向的微区。冷变形晶粒内部各微区取向连续变化,并且逐渐向近立方取向靠近。冷变形晶粒内部立方取向的微区作为形核的核心,在退火过程中利用(100)晶粒低表面能和γ→α相变最终发展成为具有集中立方织构的柱状晶组织。     

再结晶退火温度对高强IF钢组织性能及织构的影响

研究了退火温度对高强IF钢组织性能及再结晶织构的影响。结果表明,随着退火温度的升高,铁素体晶粒长大,IF钢的抗拉强度下降,伸长率先增大后减小,r值逐渐增大;退火后表现为较强的{111}<110>和{111}<112>γ纤维织构,且强点集中在{111}<112>取向,退火温度为840℃时该两取向织构密度值均较大且相差较小。     

高磁感取向硅钢27QG090的常化退火工艺

采用中试试验平台完成高磁感取向硅钢27QG090实验室常化退火工艺过程,利用光学显微镜、X射线衍射仪、透射电镜和能谱仪分析常化退火处理后试样的显微组织和宏观织构。结果表明,高磁感取向硅钢27QG090常化退火后的显微组织为铁素体,宏观织构主要是以α织构、α^*织构、铜型织构为主,兼有微弱的高斯织构,常化退火后的析出物主要是AlN,其平均尺寸约为40 nm。综合分析得出最优的常化退火工艺为1120℃×3 min+920℃×3 min, 100℃水淬。     

Comparison of earing behavior between continuous cast and direct chill cast AA 5182 aluminum alloys during cold rolling and annealing

The evolution of texture and earing during rolling of continuous cast (CC) and direct chill (DC) cast AA 5182 aluminum alloys was investigated. The results showed that the CC alloy possessed a significantly weaker cube texture than the DC alloy after annealing at 454 °C for 3 h. The evolution of texture and earing during rolling was strongly affected by the initial texture. The 45° earing value of the CC alloy increased with increasing rolling reduction, while the 0/90° earing value of the DC alloy decreased. After 45% cold rolling reduction, the deep-drawn cup of the DC alloy exhibited eight ears at 0°, 45° and 90° to the rolling direction. The DC sheet with minimum earing was obtained at about 83% rolling reduction. The evolution of texture and earing during annealing of the CC and DC alloys was compared. An empirical relationship between the earing value and texture volume fractions was established. Minimization of earing could be achieved by balancing the cube, r-cube and β fiber components.     

试论我国高品质ERW焊管发展的技术路线

国内中小产量的ERW焊管生产线虽多,但档次普遍不高,且存在装备不全、技术能力薄弱等问题,以焊接油井管和管线管为例阐述了高品质ERW焊管的发展对策。主要分析了ERW焊管的市场前景和产品定位;提出了高品质ERW焊管产品的规格范围;指出应完善ERW焊管生产线的工艺流程,特别注意主线设备工艺与配套生产线（管加工、热处理）的相互衔接,以构建一个完整的高品质产品产业链,从而提高产品的竞争力。