Relationship Between Hydrogen Solubility and Reboiling Tendency in Enameling Steels

Enameling steels that had exhibited various degrees of reboiling behavior after ground-coat enameling were charged with hydrogen to saturation by immersion in 2 N sulfuric acid at 38° C. Hydrogen contents were then determined by warm extraction at 160° C. under mercury. It is shown that for a given grade of steel the specimens which had been rated as heavy reboilers in the enameling tests occluded at 38° C. considerably less hydrogen than those rated as trace or light reboilers. A given level of hydrogen solubility, however, does not necessarily indicate the same reboiling tendency for different grades of steel. The determination of hydrogen solubility by the techniques described provides a method of indicating the reboiling tendency of a particular steel that is independent of the effects introduced by ground-coat composition.     

合金元素对冷轧钢板涂搪性能的影响

分析了添加钛和硼超低碳冷轧钢板的显微组织、力学性能、夹杂物和析出相,分别测定了冷轧退火态和经不同压下率冷轧后的冷轧轧硬态钢板的氢渗透时间。试验结果表明,添加不同合金元素的冷轧钢板在抗鳞爆性能和抗针孔性能等方面显现出不同的特点,对在实际应用中合理选材具有指导作用。     

Influence of Cold Reduction on Hydrogen Behavior in High-Purity Iron

Experiments to determine the effect of cold reduction on the behavior of hydrogen in high-purity sheet iron were conducted using two laboratory-melted heats. One heat was air-melted and poured and contained 0.00470 carbon and 0.17% oxygen; the other was vacuum-melted and poured and contained 0.003% carbon and 0.006% oxygen. An increase in hydrogen solubility (acid-charged) with increasing cold reduction was observed for both lots. The hydrogen solubility increase occurring from 0 to 80% cold reduction was much more pronounced, however, for the lot containing the higher amount of oxygen. Ground-coat reboiling tests were made on both lots of high-purity iron. The material containing high oxygen exhibited light reboiling for all levels of cold reduction, whereas the material containing low oxygen exhibited light reboiling for intermediate levels of cold reduction and heavier reboiling for low and for high levels of cold reduction. For the cold-reduced material containing high oxygen, the frequency of delayed defects decreased with increasing cold reduction. For the purer material, delayed defects were observed only for the specimens having the highest level of cold reduction.     

Enameling of Brass

The reasons for the origination of defects in enameling watch bracelets made of L-90 brass are investigated using the methods of chemical and microstructural analysis. It is demonstrated that the defects are due to the increased content of bismuth and lead in the alloy. A method for eliminating the defects is proposed.     

3种测试溶液对搪瓷用钢抗鳞爆性能评价指标的影响

采用3种常见的测试溶液检测了10组搪瓷用钢板的氢渗透性能,并同时采用涂搪实验进行验证。结果显示,测试溶液A适用于试验选定的各种厚度的搪瓷用钢,其检测结果准确率可达100%;而溶液B和溶液C在测试厚度1.5 mm以上的搪瓷用钢板料出现部分误判现象。溶液B若基于有效氢扩散系数D_eff,其准确率为70%,若基于TH值,其准确率仅为50%;而溶液C误判率达30%。     

等离子热喷涂涂搪工艺技术研究

简要介绍了等离子热喷涂技术原理、特点和作用,研究了适合热喷涂工艺技术的搪瓷瓷釉和喷涂搪瓷粉末,以及适合釉料喷涂的热喷涂工艺技术参数。研究结果表明,在厚钢板表面,采用特殊的瓷釉粉末,通过热喷涂技术可以进行搪瓷表面的喷涂,该工艺特别适合于大型搪瓷设备的表面涂搪。     

Some Influences of Carbon in Enameling of Steel

Analyses of the gases produced by carbon-bearing ferrous materials, fired in an oxidizing environment with or without enamel bisque, are correlated with the enameling properties and the microstructures of the materials. Total carbon content, or total volume of carbon oxides producible in designated circumstances, is not a reliable guide to enameling behavior form and distribution of the carbide phase are critically significant. A vacuum system for extraction and analysis of gases is described.     

Zn-Ni合金电沉积过程中的渗氢行为

用电化学渗氢测试方法探讨了氯化物体系、硫酸盐-氯化物混合体系电沉积Zn-N i合金镀层过程中的渗氢行为。结果表明,氯化物体系比硫酸盐-氯化物混合体系渗氢电流小,用电镀过程中的氢覆盖率和镀层孔隙率对渗氢特点进行了解释。     

超长搪瓷管制造工艺研究

超长钢管的涂搪和烧成是搪瓷行业的一项技术难题,本文研究开发了长度超过6 m钢管的涂搪和烧制工艺。采用搪瓷粉末静电喷涂(干搪),电阻炉预热和中频感应加热,成功研发出长度超过6 m的钢管搪瓷,得到的搪瓷钢管瓷层厚度均匀,管体挺直不变形,搪瓷表面光滑致密,耐酸、耐热冲击性能优异。超长的搪瓷管可用于极端环境,例如烟气换热器(GGH)。     

Oxidation of Iron Pretreated for Porcelain Enameling

The thickness of oxide layers formed on enameling iron at short times was measured as a function of temperature to compare the effects of three pretreatments: (1) sulfuric acid pickle, (2) nickel flash, and (3) phosphate coating. The oxides present were examined by X-ray diffraction and metallographic techniques. Nickel-flashed specimens exhibited lowered oxidation rates. The phosphate coating produced significantly rougher metal-oxide interfaces under the process conditions used.     

双氧水—丙烯—甲醇体系的相态研究

钛硅分子筛催化丙烯环氧化是生产环氧丙烷的清洁工艺,其多相反应体系的相态研究是优化该反应体系的基础.采用可视相平衡仪对不同氧化剂体系（50％双氧水体系和30％双氧水体系）、不同温度（30～80℃）、不同压力（0.8～3.5 MPa）、不同物料配比[甲醇∶双氧水（摩尔比）为5～20,丙烯∶双氧水（摩尔比）为1～4]的进料体系进行了相态观测.结果表明,丙烯进料量和甲醇含量是影响体系相态的关键因素.在相同物料配比和相近的丙烯进料量下,50％双氧水体系比30％双氧水体系液相更易达到均相.此外,对于两种双氧水-丙烯-甲醇体系,甲醇含量一定时,丙烯的进料量越小,体系液相越易呈均相状态.总之,为了使丙烯和双氧水能在液相中充分接触,应使丙烯进料量接近体系温度、压力下丙烯在双氧水-甲醇溶液中的饱和溶解度.     

High-Temperature Oxidation Behavior of Solution Precursor Plasma Sprayed Nanoceria Coating on Martensitic Steels

Solution precursor plasma spray (SPPS) is used to deposit nanoceria coating on a 410 martensitic stainless steel. The process of pyrolysis in converting the cerium nitrate solution to cerium oxide, the microstructure and the surface chemistry is confirmed by thermodynamic calculations, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. Subsequent exposure of the coated steel in atmospheric air to cyclic oxidation at 1000°C revealed excellent corrosion resistance of the steel in presence of the SPPS-processed nanoceria coating. The formation of the nanostructured (10–100 nm) ceria coating is studied using transmission electron microscopy. Relative Ce⁴⁺ and Ce³⁺ concentration in the coating was determined from XPS high-resolution spectrum. Cross-section scanning electron microscopy showed the presence of an impervious nature of the protective layer with reduced scale thickness in the coated-oxidized sample. After a pre-oxidation treatment at 1273 K of the coated specimen, the oxidation kinetics showed a significant decrease as compared with the uncoated martensitic steel.     

电沉积Zn-Fe合金的渗氢行为研究

用双电解池测氢法研究氯化物镀液体系中电沉积Zn-Fe合金过程中的渗氢行为.结果表明:在所考察的工艺参数中,镀液pH值对渗氢电流的影响最大.用慢应变速率拉伸试验法(SSRT)考察了电镀Zn-Fe合金试样的氢脆特性,并用扫描电子显微镜(SEM)对断口的微观形貌进行了表征.所有Zn-Fe合金镀层的试样均显示出不同程度的氢脆敏感性.     

Role of Nickel Dip in Enameling of Sheet Steel

An investigation was made of the effects of (a) the firing time and (b) the weight of nickel deposited from the nickel-dip solution on the adherence developed by a cobalt-free and a cobalt-bearing ground-coat enamel on both enameling iron and a titanium-bearing low-carbon steel. At 1550°F. the nickel improved the measured adherence index the most during the 2-minute firing. The effect of the nickel, however, decreased markedly with longer firing times. There was an optimum nickel deposit for maximum adherence, an optimum that varied from 50 to about 120 mg. per sq. ft., depending on the type of cleaning used and on the type of enamel applied. The nickel dip reduced the tendency to fish-scale. Furthermore, there was an apparent relation between fish-scaling resistance and good adherence; no specimen with an adherence index of 70 or above showed fish-scaling tendencies. Metallographic studies of the interface of coated specimens showed that nickel dipping of the steel before enameling brought about a surface roughening during the firing operation. A relationship was noted between the degree of roughening and the measured adherence index. The roughening of the steel surface was ascribed to galvanic corrosion.     

铝锌镀层钢板搪瓷烧成工艺的探讨

将铝锌镀层钢板搪瓷在一定温度下不同时间烧成,通过金相、扫描电镜和能谱仪对样品横切面进行分析,探讨不同的烧成工艺对搪瓷烧成结果的影响。     

Oxide Adherence and Nickel Flashing in Vitreous Enameling

The influence of iron deposition and nickel flashing on the adherence of oxides to enameling-grade sheet steel has been examined. Nickel flashing promotes oxide adherence, and a correlation between oxide adherence and adherence of a directly applied titania self-opacified cover-coat enamel has been established. Further work is necessary, however, to obtain a satisfactory enamel surface texture under these conditions before the direct application of a cover-coat enamel can become a commercial possibility. Similarly, good adherence of a titania self-opacified cover coat applied directly to steel has been promoted by nitric acid pickling with and without a nickel-flashing treatment. Finally, the iron content of a hydrochloric acid pickling bath and the amount of hydrogen absorbed by the steel during pickling have been shown to influence the amount of nickel deposited on the steel during flashing.     

不同换热管用钢材的搪瓷密着性能研究

通过落球冲击法评价了低碳钢(20钢)和耐候钢(09CrCuSb)搪瓷密着强度,并采用扫描电镜和能谱仪分析了钢材与搪瓷结合层的微观形貌及成分。结果表明:低碳钢和耐候钢的搪瓷密着等级分别为2级和5级;低碳钢与瓷釉界面形成了锯齿状和枝晶状结构,界面粗糙,而耐候钢与瓷釉界面形成了脱离基体的岛状结构,界面较光滑;结合层主要成分均为Fe、Cu、Ni、Co元素;钢材与瓷釉之间形成粗糙的界面有利于提高搪瓷密着性能。     

氢键对有机取代反应和加成反应的影响

取代反应和加成反应是有机化学中最基础、最重要、也是研究最多的反应。影响取代反应和加成反应的因素很多,文章从氢键的形成、类型、键能大小出发,分析讨论了其对饱和碳原子上亲核取代反应、苯环上C-F键的亲核取代反应、亲电加成反应及羰基化合物亲核加成反应的影响,所得结论对有机化学理论教学和有机合成具有一定的指导意义。     

辐射管搪烧炉传热数学模型研究

利用假想平面法建立了室式辐射管搪烧炉传热数学模型,并进行了仿真计算,结果表明,假想平面法能够大大简化室式辐射管搪烧炉内大量的角系数的计算,并可对炉子的有关参数(如辐射管的距径比、布置、炉墙结构等)进行优化计算。