冷轧无取向硅钢的织构和组织性能分析

分析和讨论了国内外牌号为50W800和50W600，50H1300，50A1300的4种普通冷轧无取向硅钢的成分、组织、织构对磁性的影响。根据织构取向分布函数(ODF)分析结果，得出为获得高的无取向硅钢磁性能，硅钢除具有高的纯净度，低的夹杂物含量，组织均匀、晶粒细小外，应控制产品形成{HKL}面织构，尤其是{100}面织构，以便同时降低铁损和提高磁感。     

保温时间对锰氧化物刻蚀金刚石单晶的影响

研究了在不同保温时间下MnO₂对金刚石单晶的表面刻蚀, 通过扫描电子显微镜和拉曼光谱对刻蚀后金刚石单晶不同晶面的表面形貌和刻蚀机理的进行了表征与分析, 并对腐蚀过程中金刚石表现出来的各向异性进行了探讨。结果表明: 当金刚石和MnO₂质量比为1:5时, 金刚石单晶的刻蚀程度随着保温时间的延长而增大; 在相同保温时间下, {111}晶面比{100}晶面刻蚀严重; 金刚石表面腐蚀后的形貌与对应晶面的碳原子排列有关, {100}面倾向于形成四边形的刻蚀坑, 而{111}面则会形成轮廓为三角形的腐蚀坑, 且金刚石单颗粒的抗压强度随刻蚀时间的延长而下降; 刻蚀机理为MnO₂与金刚石表面C原子发生反应, 导致金刚石表面发生刻蚀。     

微碳深冲钢板非{111}织构的形成过程

结合实际生产,采用金相分析、织构测量和透射电镜等方法,研究了微碳深冲钢板中出现的非{111}织构在钢板再结晶时的形成过程,并分析了非{111}织构与冷轧压下率和析出物的关系。研究结果表明：非{111}织构在冷轧变形后即已形成,冷轧压下率较小时,非{111}织构组分相对{111}织构较强;冷轧组织中存在的非{111}取向晶粒在退火过程中会优先成核和优先生长;非{111}织构的形成对AlN的析出不敏感。     

反应溅射法在蓝宝石衬底上制备CeO2缓冲层

用金属铈作为靶材,采用射频反应磁控溅射法在（1 102）蓝宝石衬底上制备C轴取向CeO2外延薄膜缓冲层。结果表明在温度低于450℃或溅射功率低于50 W的条件下CeO2薄膜呈（111）取向生长;升高温度和功率CeO2薄膜的（111）取向减弱,（002）取向增强;在温度高于750℃或溅射功率高于120 W条件下CeO2薄膜呈（111）取向和（002）取向混合生长。结合X射线衍射仪和原子力显微镜表征CeO2薄膜的结构和表面形貌,获得在最优化条件下（衬底温度在680℃左右,溅射功率在80 W左右,溅射气压在25 Pa,氩氧比在15∶1）制备的CeO2薄膜具有优良的面内面外取向和平整的表面。     

50W600正常晶粒长大过程中再结晶织构演化研究

运用EBSD技术研究了50W600无取向硅钢再结晶晶粒正常长大过程中织构的演化机理。结果表明:再结晶晶粒长大过程中织构演化源于不同织构组分长大速率不同;晶粒尺寸不是唯一决定某取向晶粒长大的因素;晶粒与其周围其它晶粒取向差角分布是影响该晶粒长大的重要参数;{111}<112>与{111}<110>取向晶粒长大过程中的相互竞争导致{111}面织构取向锋锐度交替变化;950℃退火时,随退火时间延长,{100}<120>织构、{100}<310>织构减弱,{110}<001>增强;恒定退火时间3.5 min,随退火温度升高,{110}<001>、{100}<120>、{100}<310>织构均增强;温度对不同取向晶粒取向差角分布有较大影响。     

热轧板初始组织对冷轧无取向硅钢织构演变的影响

研究了27.5 mm热轧板的初始组织(热轧态,850℃退火、950℃退火)对冷轧态和870℃退火的0.5mm冷轧无取向硅钢50W600薄板(/%:0.004C、0.33Si、0.38Mn、0.099P、0.007S、0.32Al)织构演变的影响。结果表明,经冷轧后冷轧板织构中{100}〈011〉和{112}〈110〉织构密度明显增大,末退火热轧板轧成的冷轧板织构密度较退火热轧板轧成的冷轧板强;经未退火热轧板冷轧成的薄板再结晶退火后的织构中主要为{100}〈011〉、{110}〈011〉和{111}〈112〉,退火热轧板冷轧成的薄板再结晶退火后的织构除{100}〈011〉和{110}〈011〉外还有密度较强的高斯织构。     

Sn含量对CSP流程高磁感无取向电工钢磁性能的影响

通过X射线衍射和EBSD的分析方法,就0.050%~0.012%含量的Sn对高磁感无取向电工钢织构和电磁性能的影响进行了分析。研究结果表明,Sn作为一种表面活性元素,其主要是降低{111}面织构比例,提高{011}和{100}面织构。在相同的冷轧和退火条件下,{011}和{100}面织构比例、高斯晶粒含量均随Sn含量增加而升高,但Sn含量与成品的平均晶粒尺寸影响不显著。     

粉末冶金高速钢的精细结构

应用分析电子显微术对粉末冶金高速钢的精细结构进行了研究。 Speed法萃取复型衍衬象研究结果表明,PT15和Rex25粉末冶金高速钢中二次析出碳化物的生长满足由扩散控制的生长动力学方程 PT15和Rex25钢中的二次析出碳化物与基体的取向关系与文献报道的取向关系相符。合金碳化物晶格常数的变化未导致新的取向关系。 MMD方法对Rex25钢的研究结果表明存在MC和M_2C伴生形核现象。MC碳化物择优在碳原子有序化的{100}_α面上形核。 应用会聚束电子衍射术对MC碳化物的点阵常数进行了测量。结果为a=4.2245 。高合金化没有导致MC自身结构和对称性的变化。     

50W600 冷轧无取向电工钢退火过程组织和织构取向的演变

通过金相和电子背散射衍射法(EBSD)研究50W600冷轧无取向电工钢(0.003%～0.008%C、0.3%Si)在700～760℃3～360 s退火水冷时的组织和织构取向演变.结果表明,随退火温度的提高,钢的再结晶率和晶粒尺寸增大,740℃退火时,当保温时间由10 s增加至360 s,再结晶率由22.5%提高到100%,平均晶粒尺寸由3.08μm增大至17.17 μm.同时再结晶织构a线的取向密度下降,在15 8时{001}<110>、{112}<110>、{111}<110>、{110}<110>的取向密度均为1.5左右,y线上{111}<011>和{111}<112>的取向密度稳定在0.25左右.     

无取向电工钢冷轧及退火织构的演变

运用不同冷轧、退火工艺的实验及ODF分析方法,分析了电工钢50W600的热轧织构、冷轧织构及再结晶织构的演变.研究表明:热轧带几乎是随机织构,α线非常弱;随着冷轧变形量的提高,晶粒在α线取向附近聚集程度不断提高,变形81%时,{001}《110》和{112}《110》取向密度分别为12和14.随退火温度升高和保温时间延长,α线的取向密度下降,{001}《110》和{112}《110》取向密度急剧降低,γ线{111}《112》密度显著增加,晶粒取向绝大多数聚集在γ线{111}《112》取向附近.通过控制冷轧及退火工艺,可有利于发展高{100}织构组分的冷轧无取向电工钢.     

Microstructural evolution in iron aluminide Fe-28Al-2C after high-temperature hydrogen treatment

High-temperature hydrogen attack (HA) in a carbon-alloyed iron aluminide of composition Fe-28.1Al-2.1C (in at. pct) has been studied. Well-polished samples were exposed to hydrogen gas (1 atm) at 700 °C and 900 °C for different times. The characteristics of HA were evaluated by two-dimensional microstructural analysis, performed on the rolling plane of the as-received and hydrogen-treated samples. The carbon-alloyed iron aluminide contained carbides in two different morphologies: blocky and needle shaped. The compositions of these carbides have been determined. The blocky carbides were preferentially attacked along the {111} and {110} crystallographic planes. The interfaces between the blocky carbides and grains were mainly affected by the hydrogen treatment. The needle-shaped carbides dissolved in the matrix after relatively short times. The degree of attack generally increased with increases in treatment temperature and time of exposure, as long as the surface was not completely covered with a protective oxide layer.     

摩擦对IF钢铁素体区热轧和退火织构的影响

采用X射线衍射仪分析IF钢铁素体区热轧织构以及退火织构的演化,在实验室热轧机上进行了IF钢的铁素体区热轧,研究了摩擦对IF钢铁素体区热轧、退火织构的影响。结果表明：无润滑轧制时,钢板表层形成强高斯织构组分{110}〈001〉,弱γ纤维织构,导致再结晶织构中高斯组分强度高,γ纤维织构强度低;润滑轧制时,钢板表层高斯织构组分强度降低,{100}〈011〉、γ纤维织构强度提高,退火后γ纤维织构强度提高。钢板中心受摩擦作用影响较小,轧制过程中发展为较强的α和γ纤维织构,退火后γ纤维织构成为主要织构组分。     

First-Principles Calculations on Stabilization of Iron Carbides (Fe3C, Fe5C2, and η-Fe2C) in Steels by Common Alloying Elements

The control of carbide formation is crucial for the development of advanced low-alloy steels. Hence, it is of great practical use to know the (de)stabilization of carbides by commonly used alloying elements. Here, we use ab initio density functional theory (DFT) calculations to calculate the stabilization offered by common alloying elements (Al, Si, P, S, Ti, V, Cr, Mn, Ni, Co, Cu, Nb, Mo, and W) to carbides relevant to low-alloy steels, namely cementite $(\hbox{Fe}_{3}\hbox{C}),$ H?gg $(\hbox{Fe}_{5}\hbox{C}_{2}),$ and eta-carbide $(\eta{\text{-}}\hbox{Fe}_{2}\hbox{C})$ . All alloying elements are considered on the Fe sites of the carbides, whereas Al, Si, P, and S are also considered on the C sites. To consider the effect of larger supercell size on the results of (de)stabilization, we use both 1?×?1?×?1 and 2?×?2?×?2 supercells in the case of $\hbox{Fe}_{3}\hbox{C}.$      

Morphology,microhardness, and grinding ability of single-crystal powders

Conclusions A study was made of the variation of the morphology and size of TiC and TaC crystals as functions of cooling rate of solutions of these carbides in molten Al (in the mass crystallization process). TiC and TaC were found for the first time to be characterized by polar as well as by reticular anisotropy of microhardness on their (111) faces. It was confirmed that the slip systems in TiC and TaC are {110} [110] and {111} [110], respectively. It is shown that TiC and TaC single crystals surpass corundum and fused carbides (TiC) in grinding ability and strength of individual grains.Translated from Poroshkovaya Metallurgiya, No. 8(224), pp. 76–80, August, 1981.     

Influence of Cast Dimension on Rotary Bending High Cycle Fatigue Properties of Single Crystal Superalloy

Samples of DD3 single crystal superalloy with different dimensions were cast in the directionally solidified furnace with high temperature gradient. The effect of cast dimension on the rotary bending high cycle fatigue (HCF) properties of the alloy was investigated at 800 °C in ambient atmosphere. SEM was used to examine the fracture surface and fracture mechanism of the alloy. The results show that the rotary bending HCF properties of the alloy decreases with increasing cast dimension. The cast dimension has little effect on the HCF fracture mechanism of the alloy. The HCF fracture mechanism of the alloy with different cast dimensions is all quasi-cleavage fracture. The fatigue cracks initiated on the surface or near the surface of the specimens. The crack would propagate along {111} octahedral slip planes. Typical fatigue arc and striation formed on fatigue crack steady propagation. The degeneration of HCF properties is due to the increase of dendrite arm spacing and size of γ′ phase particles and maximal microporosity.     

Microreaction mechanism in reduction of magnetite to wustite

In order to understand the microreaction mechanism of the reduction of magnetite to wustite, hydrogen ions were implanted into magnetite at room temperature by an ion accelerator. The crystalloid transformation during the reduction process was investigated by using selected-area electron diffraction patterns. The experimental results showed that {220} planes on the surface of magnetite were changed first because the concentration of oxygen ions on the {220} planes is higher than other planes to follow the reaction of oxygen ions with hydrogen ions, leaving the {220} planes and resulting in rearrangement of ions. On the other hand, oxygen ions migrate more difficulty than iron ions in magnetite; therefore, {220} planes in the bulk are more stable than other planes. Based on the experimental facts, two kinds of microreaction mechanisms in reduction of magnetite to wustite are suggested. It was found that (1) wustite with [001] direction was formed on the magnetite with [001] direction, (2) (220) and (200) planes of wustite were parallel with (220) and (400) planes of magnetite, respectively, in crystal structure between parent phase and new phase, (3) some {220} planes were formed earlier than other ones in wustite during the reduction process. These results can be considered as due to the similar geometric distribution of oxygen ions between magnetite and wustite.     

Formation of Fe3N,Fe4N and Fe16N2 on the surface of iron

In order to clarify the phenomenon of nitride formation on the surface of iron, highly polished specimens of well refined and coarsened iron grains have nitrided in flowing H2 + NH3 gas. The morphology and the conditions for formation of Fe₃N are clarified; it forms only on the surface of {lll}_α or near {lll}_α grains and grows in {112}_α directions during nitriding treatment at temperatures between 450 and 550°C. Fe₁₆N₂ and Fe₄N are also formed preferentially on the surfaces of {00l}_α and {210}_α grains, respectively. It is suggested that these iron surfaces are those satisfying the coherency relationships between nitrides and iron matrices. The morphologies and the formation temperature regions of Fe₁₆N₂ and Fe₄N on the surface of iron are quite different to those observed in iron. In particular, Fe₁₆N₂, which has been generally accepted as metastable in bulk iron below 200°C, can exist even at temperatures from 450 to 500°C when it is formed on the surface of iron.     

Formation of Fe3N, Fe4N and Fe16N2 on the surface of iron

In order to clarify the phenomenon of nitride formation on the surface of iron, highly polished specimens of well refined and coarsened iron grains have nitrided in flowing H2 + NH3 gas. The morphology and the conditions for formation of Fe₃N are clarified; it forms only on the surface of {lll}_α or near {lll}_α grains and grows in {112}_α directions during nitriding treatment at temperatures between 450 and 550°C. Fe₁₆N₂ and Fe₄N are also formed preferentially on the surfaces of {00l}_α and {210}_α grains, respectively. It is suggested that these iron surfaces are those satisfying the coherency relationships between nitrides and iron matrices. The morphologies and the formation temperature regions of Fe₁₆N₂ and Fe₄N on the surface of iron are quite different to those observed in iron. In particular, Fe₁₆N₂, which has been generally accepted as metastable in bulk iron below 200°C, can exist even at temperatures from 450 to 500°C when it is formed on the surface of iron.     

The Observation of the Structure of M<Subscript>23</Subscript>C<Subscript>6</Subscript>/<Emphasis Type="Italic">γ</Emphasis> Coherent Interface in the 100Mn13 High Carbon High Manganese Steel

The M₂₃C₆ carbides precipitate along the austenite grain boundary in the 100Mn13 high carbon high manganese steel after 1323 K (1050 °C) solution treatment and subsequent 748 K (475 °C) aging treatment. The grain boundary M₂₃C₆ carbides not only spread along the grain boundary and into the incoherent austenite grain, but also grow slowly into the coherent austenite grain. On the basis of the research with optical microscope, a further investigation for the M₂₃C₆/γ coherent interface was carried out by transmission electron microscope (TEM). The results show that the grain boundary M₂₃C₆ carbides have orientation relationships with only one of the adjacent austenite grains in the same planes: \( (\bar{1}1\bar{1})_{{{\text{M}}_{ 2 3} {\text{C}}_{ 6} }} //(\bar{1}1\bar{1})_{\gamma } , \) \( (\bar{1}11)_{{{\text{M}}_{ 2 3} {\text{C}}_{ 6} }} //(\bar{1}11)_{\gamma } ,[ 1 10]_{{{\text{M}}_{ 2 3} {\text{C}}_{ 6} }} //[ 1 10]_{\gamma } \). The flat M₂₃C₆/γ coherent interface lies on the low indexed crystal planes {111}. Moreover, in M₂₃C₆/γ coherent interface, there are embossments which stretch into the coherent austenite grain γ. Dislocations distribute in the embossments and coherent interface frontier. According to the experimental observation, the paper suggests that the embossments can promote the M₂₃C₆/γ coherent interface move. Besides, the present work has analyzed chemical composition of experimental material and the crystal structures of austenite and M₂₃C₆, which indicates that the transformation can be completed through a little diffusion for C atoms and a simple variant for austenite unit cell.     

The morphology,crystallography, and mechanism of carbide precipitation in an Fe-0.12 Pct C-3.28 Pct Ni alloy

Carbide precipitation during the eutectoid decomposition of austenite has been studied in an Fe-0.12 pct C-3.28 pct Ni alloy by transmission electron microscopy (TEM) supplemented by optical microscopy. Nodular bainite which forms during the latter stages of austenite decomposition at 550 °C exhibits two types of carbide arrangement: (a) banded interphase boundary carbides with particle diameters of about 20 to 90 nm and mean band spacings between 180 and 390 nm and (b) more randomly distributed (“nonbanded”) elongated particles exhibiting a wide range of lengths between 33 and 2500 nm, thicknesses of approximately 11 to 50 nm, and mean intercarbide spacings of approximately 140 to 275 nm. Electron diffraction analysis indicated that in both cases, the carbides are cementite, obeying the Pitsch orientation relationship with respect to the bainitic ferrite. The intercarbide spacings of both morphologies are significantly larger than those previously reported for similar microstructures in steels containing alloy carbides other than cementite (e.g., VC, TiC). Both curved and straight cementite bands were observed; in the latter case, the average plane of the interphase boundary precipitate sheets was near {110}_α//{011}_c consistent with cementite precipitation on low-energy {110}_α//{111}_γ ledge terrace planes (where α,β, andc refer to ferrite, austenite, and cementite, respectively). The results also suggest that the first stage in the formation of the nonbanded form of nodular bainite is often the precipitation of cementite rods, or laths, in austenite at the α:γ interfaces of proeutectoid ferrite secondary sideplates formed earlier. Although these cementite rods frequently resemble the “fibrous” microstructures observed by previous investigators in carbide-forming alloy steels, they are typically much shorter than fibrous alloy carbides. The bainitic microstructures observed here are analyzed in terms of a previously developed model centered about the roles of the relative nucleation and growth rates of the product phases in controlling the evolution of eutectoid microstructures.