奥氏体─贝氏体抗磨钢中共晶体的团球化

用扫描电镜、透射电镜和电子探针研究Mg－Al复合变质奥─贝钢中共晶体的团球化结果表明，团球状共晶体是由于C、Mn、Si偏析，于凝固后期在奥氏体校晶间形成的渗碳体和奥氏体伪共晶组织，共晶体结晶时的异质核心是MgS．团球化是异质核心和变质元素影响共晶体的结晶方式     

Si对团球状共晶体奥氏体—贝氏体钢中贝氏体相变的影响

在热力学，动力学的基础上，从贝氏体铁素体在奥氏体贫碳区切变机制出发，研究了Ｓｉ对团球状共晶体奥－贝钢中贝氏体相变的影响，并提出Ｓｉ促使奥氏体奥碳区的形成，有利于贝氏体切变的新观点。     

MgO—B2O3—SiO2—Al2O3—CaO中含硼组分析晶动力学

根据玻璃形成动力学理论，计算了ＭｇＯ－Ｂ２Ｏ３－ＳｉＯ２－Ａｌ２Ｏ３－ＣａＯ渣系中含硼组分２ＭｇＯ·Ｂ２Ｏ３的成核速度（Ｉ）和晶体长大速度（Ｕ），获得了２ＭｇＯ·Ｂ２Ｏ３晶体形成的最佳温度．采用化学分析、Ｘ射线衍射分析（ＸＲＤ）和差热分析（ＤＴＡ）等方法研究了热处理温度对ＭｇＯ—Ｂ２Ｏ３—ＳｉＯ２—Ａｌ２Ｏ３—ＣａＯ渣系硼提取率的影响．结果表明：硼渣最佳热处理温度与２ＭｇＯ·Ｂ２Ｏ３晶体形成最佳温度一致。     

尼龙1010/HDPE-g-MAH共混体系界面形态及结晶行为的研究

通过Ｍｏｌａｕ实验、密度测定、二甲苯萃取物的ＩＲ分析以及ＤＳＣ、ＳＥＭ等手段，对尼龙１０１０／ＨＤＰＥ－ｇ－ＭＡＨ共混体系的界面形态和结晶行为进行了研究。结果表明，共混体系为热力学不相容体系；在熔融共混过程中，尼龙１０１０和ＨＤＰＥ－ｇ－ＭＡＨ发生化学反应，生成的接枝共聚物起到了共混体系相容剂的作用，分散和界面形态明显改善；共混体系中两相的结晶行为也受到影响，尼龙组分的熔融热焓明显下降。     

合成条件对TS—2沸石的合成和催化性能的影响

本文通过改变Ｈ２Ｏ／ＳｉＯ２比、Ｓｉ／Ｔｉ比、模板剂的用量以及胶液的ＰＨ值等条件，合成了一系列ＴＳ－１沸石，用ＸＲＤ、ＩＲ和ＳＥＭ系统地考察了上述因素对合成手ＴＳ－１沸石的结晶纯度、骨架钛含量以及其晶体形貌４的影响；用苯酚羟基化反庆考察了其催化性能，就沸石的结晶度、骨架钛量，特别是晶体形貌与其催化活性的关系进行了探讨，找具有较高催化活性的ＴＳ－２分子筛的合成方法。     

几类重要的反应性高分子应用研究进展

本文主要叙述了ＰＥ－ｇ－ＭＡＨ，ＰＰ－ｇ－ＭＡＨ，ＥＰＤＭ－ｇ－ＭＡＨ，ＰＳ－ｇ－ＧＭＡ，ＳＥＢＳ－ｇ－ＧＭＡ，ＰＰ－ｇ－ＡＡ等几种反应性高分子的制备及应用，研究现状和它们未来发展的趋势。     

CaO—MgO—Fe2O3—Al2O3—SiO2渣系玻璃晶化动力学

根据玻璃形成动力学理论,计算了ＣａＯ－ＭｇＯ－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２渣系中成核速率（Ｉ）和晶体长大速度（Ｕ）,获得晶体形成的最佳温度,研究了热处理温度对ＣａＯ－ＭｇＯ－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２渣系晶体的影响,计算的晶体形成的最佳温度结果表明与该体系的最佳热处理温度一致。     

BAS玻璃陶瓷的晶化行为与性能

用ＸＲＤ，ＤＴＡ，ＳＥＭ，ＴＥＭ和三点弯曲试验研究了溶胶－凝胶法合成的ＢＡＳ（ＢａＯ．Ａｌ２Ｏ３．２ＳｉＯ２）凝胶玻璃的结晶行为，晶型转变和热压ＢＡＳ的显微结构与性能，结果表明，ＢＡＳ凝胶玻璃法〉１０００℃时开始析晶，１１００℃时完全晶化，结晶相为六方钡长石，不加成核剂，呈现整体结晶特性，晶粒小于１μｍ加入５０ｍｇ．ｇ＾－１单斜钡长石作为晶种，可促进六方→单斜晶型转变，在１２５０℃处理７ｈ约有８０     

PVC/PA1010/SBS-g-MAH共混体系研究

制备了ＳＢＳ－ｇ－ＭＡＨ接枝聚合物,并对其进行了表征,以ＳＢＳ－ｇ－ＭＡＨ作为ＰＶＣ／ＰＡ１０１０共混体系的增剂,对不同配比的ＰＶＣ／ＰＡ１０１０／ＳＢＳ－ｇ－ＭＡＨ共混体系的物理力学性能,流变性及差热性等进行了研究,结果表明,ＳＢＳ－ｇ－ＭＡＨ接枝聚合物对ＰＶＣ／ＰＡ１０１０共混体系起到了明显的增容作用,得到了缺口冲击强度及拉伸强度均较高的ＰＶＣ／ＰＡ１０１０／ＳＢＳ－ｇ－ＭＡＨ共混物。     

碳化物团球化奥氏体—贝氏体新型抗磨中锰钢

在中锰钢基础上，采用变质处理获得新型铸态抗磨钢：碳化物团球化奥氏体－贝氏体钢，它具有高强韧性，高耐磨性，是一种有广阔应用前景的新型抗磨材料。     

Solidification microstructures selection of Fe–Cr–Ni and Fe–Ni alloys

The transition of solidified phases in Fe–Cr–Ni and Fe–Ni alloys was investigated from low to high growth rate ranges using a Bridgman type furnace, laser resolidification and casting into a substrate from superheated or undercooled melt. The ferrite–austenite regular eutectic growth, which is difficult to find in typical production conditions of stainless steels, was confirmed under low growth rate conditions. The transition velocity between eutectic and ferrite cell growth had a good agreement predicted by the phase selection criterion. Which of either ferrite or austenite is easier to form in the high growth range was discussed from the point of nucleation and growth. Metastable austenite formation in stable primary ferrite composition was mainly a result of growth competition between ferrite and austenite. For a binary Fe–Ni system, a planar metastable austenite in the steady state, simultaneous growth such as eutectic and banded growth between ferrite and austenite in an initial transient region are confirmed.     

Solidification microstructures selection of Fe-Cr-Ni and Fe-Ni alloys

The transition of solidified phases in Fe–Cr–Ni and Fe–Ni alloys was investigated from low to high growth rate ranges using a Bridgman type furnace, laser resolidification and casting into a substrate from superheated or undercooled melt. The ferrite-austenite regular eutectic growth, which is difficult to find in typical production conditions of stainless steels, was confirmed under low growth rate conditions. The transition velocity between eutectic and ferrite cell growth had a good agreement predicted by the phase selection criterion. Which of either ferrite or austenite is easier to form in the high growth range was discussed from the point of nucleation and growth. Metastable austenite formation in stable primary ferrite composition was mainly a result of growth competition between ferrite and austenite. For a binary Fe–Ni system, a planar metastable austenite in the steady state, simultaneous growth such as eutectic and banded growth between ferrite and austenite in an initial transient region are confirmed.     

Microsegregation and eutectic ferrite-to-austenite transformation in primary austenite solidified CF-8M weld metals

Solidification and microsegregation studies were performed on alloy CF-8M weld metal which solidified via the primary austenite/eutectic ferrite mode. All of the major alloying elements (chromium, nickel, molybdenum) were observed to segregate to interdendritic areas upon solidification. Electron microprobe analysis revealed a substantial chromium and molybdenum enrichment of the eutectic ferrite relative to the austenite dendrites even in structures water-quenched from the solidus temperature. Scanning transmission electron microscopy/energy dispersive spectrometry (STEM/EDS) profiles taken within the eutectic ferrite phase revealed a similar pattern of major element distribution as has been observed by other investigators in residual primary delta ferrite dendrites. Within the eutectic ferrite, the highest chromium and molybdenum content and the lowest nickel content was found at the eutectic ferrite/austenite boundary. STEM/EDS analyses of in situ water-quenched weld microstructures revealed that compositional modification of the eutectic ferrite had occurred upon cooling from the solidus. In particular, the chromium concentration of the eutectic-ferrite was observed to increase by approximately 3 wt% in the temperature range 1300 to 750°C. In the same temperature range, the nickel content of the eutectic-ferrite decreased by approximately 4 wt % and the molybdenum content increased within the same phase by approximately 1 wt%. The transformation of eutectic ferrite to austenite as the weld metal cools to room temperature is consistent with a volume diffusion-control mechanism.     

12Cr2MoWVTiB钢焊缝微裂纹产生机理研究

利用透射电子显微镜技术研究了１２Ｃｒ２ＭｏＷＶＴｉＢ耐钢焊缝区产生裂纹的微观机理，文中提出，粒状贝氏中大量的富氢微孪晶马氏体Ｍ－Ａ小岛引起的延迟微裂纹；柱晶晶界间的多晶低熔共晶膜引起的结晶裂纹以及外加拘束应力等三者之间的相互作用，导致该裂纹的产生，初步讨论了避免焊缝裂纹的方法，首次在ＴＥＭ下观察到了低熔共晶膜的形态。     

原位研究M2高速钢微裂纹的萌生和扩展

使用扫描电子显微镜(SEM)内的原位加载台对M2高速钢进行了原位拉伸实验。结果表明：在M2高速钢的原位拉伸过程中,微裂纹主要在大尺寸共晶碳化物与基体的界面处萌生和扩展。与回火马氏体相比,裂纹更容易在残余奥氏体上萌生。碳化物的尺寸、形状和种类,对微裂纹的萌生和扩展也有重要的影响。减少块状残余奥氏体、一次共晶碳化物和MC碳化物的数量、减小碳化物的尺寸和改善碳化物形状,可减缓微裂纹的萌生和扩展。     

TiC as heterogeneous nuclei of the (Fe, Mn)3C and austenite intergrowth eutectic in austenite steel matrix wear resistant composite

By calculation of thermodynamics, analysis of crystal structure and study of transmission electron microscope (TEM), scanning electron microscope (SEM) and electron probe microanalyzer (EPMA), it has been discovered that TiC is formed preferentially between austenite dendrites at the end of the solidification to act as heterogeneous nuclei for the crystallization of the (Fe, Mn)₃C (cementite) and γ₂-Fe (austenite) intergrowth eutectic in the austenite steel matrix wear resistant composite.     

Electron microscopy and hardness study of a semi-solid processed 27 wt%Cr cast iron

A semi-solid processed 27 wt%Cr cast iron was studied by electron microscopy and its microstructure was related to the hardness. In the as-cast condition, the primary proeutectic austenite was round in shape while the eutectic M₇C₃ carbide was found as radiating clusters mixed with directional clusters. Growth in the [0 0 1]M₇C₃ with planar faces of {0 2 0}M₇C₃ and was usually observed with an encapsulated core of austenite. Destabilisation heat treatment followed by air cooling led to a precipitation of secondary M₂₃C₆ carbide and a transformation of the primary austenite to martensite in the semi-solid processed iron. Precipitation behaviour is comparable to that observed in the destabilisation of conventional cast iron. However, the nucleation of secondary M₂₃C₆ carbide on the eutectic M₇C₃ carbide was observed for the first time. Tempering after destabilisation led to further precipitation of carbide within the tempered martensite in the eutectic structure. The maximum hardness was obtained after destabilisation and tempering heat treatment due to the precipitation of secondary carbides within the martensite matrix and a possible reduction in the retained austenite.     

Effects of Heat Treatment on Hardness and Dry Wear Properties of a Semi-Solid Processed Fe-27 wt pct Cr-2.9 wt pct C Cast Iron

EfFects of heat treatments on hardness and dry wear properties of a semi-solid processed Fe-26.96 wt pct Cr- 2.91 wt pct C cast iron were studied. Heat treatments included tempering at 500℃, destabilisation at 1075℃ and destabilisation at 1075℃ plus tempering at 500℃, all followed by air cooling. Electron microscopy revealed that, in the as-cast condition, the primary proeutectic austenite was round in shape while the eutectic M7C3 carbide was found as radiating clusters mixed with directional clusters. Tempering did not change the microstructure significantly when observed by scanning or transmission electron microscopy. Destabilisation followed by air cooling led to a precipitation of secondary M23C6 carbide and a transformation of the primary austenite to martensite. Precipitation behaviour is comparable to that observed in the conventionally cast iron. Tempering after destabilisation resulted in a higher amount of secondary carbide precipitation within the tempered martensite in the eutectic structure. Vickers macrohardness and microhardness in the proeutectic zones were measured. Dry wear properties were tested by using a pin-on-disc method. The maximum hardness and the lowest dry wear rate were obtained from the destabilisation-plus-tempering heat treatment due to the precipitation of secondary carbides within the martensite matrix and a possible reduction in the retained austenite.     

Microstructure and properties of austenite-bainite steel matrix wear resistant composite reinforced by granular eutectics

A new austenite-bainite steel matrix wear resistant composite reinforced by granular eutectics (abbreviated ABGE composite) has been obtained by controlling the solidification structure of the steel melt, which only contains manganese and silicon, with modification of Al-Mg-Ce compound and air-hardening. It has been found that the granular eutectic is a pseudo-eutectic of austenite and (Fe,Mn)₃C, which is formed between austenite dendrites during solidification due to the segregation of C and Mn enhanced by modifying elements. The granulation of the eutectic can be explained by the heterogeneous nuclei of MgS and CeO₂ and by the influence of the modifying elements on the crystallization of the eutectic. The eutectic and bainite contents are 4%–10% and 20%–40%, respectively. The size of the eutectic is 5 m–20 m and its microhardness is HV800-1200. The wear resistance of the ABGE composite is much higher than that of the austenite-bainite steel, austenite-bainite ductile cast iron and medium manganese steel with nodular carbides under low and medium impact working condition because the granular eutectics effectively lighten the intrusion of abrasives into the worn surface and microcutting by abrasives on the worn surface and austenite-bainite matrix structure has high strain-hardening ability.