蒸馏装置高含硫渣油部位的腐蚀失效分析

结合兰州某加工高硫高酸原油炼厂蒸馏装置渣油系统发生的腐蚀火灾事故，通过对失效设备进行元素含量分析、能谱分析、原子吸收光谱分析和表面形貌及断面形貌观察，认为高温渣油系统的腐蚀主要是高温硫的腐蚀。针对该系统的腐蚀特征，提出应重点采用耐蚀材质和腐蚀监测两项防腐对策。     

TiAl ALLOYS PREPARED BY THERMAL EXTRUSION OF ELEMENTAL POWDER MIXTURES

ＴｉＡｌＡＬＬＯＹＳＰＲＥＰＡＲＥＤＢＹＴＨＥＲＭＡＬＥＸＴＲＵＳＩＯＮＯＦＥＬＥＭＥＮＴＡＬＰＯＷＤＥＲＭＩＸＴＵＲＥＳ①ＬｉｕＺｈｉｊｉａｎ，ＱｕＸｕａｎｈｕｉ，ＨｕａｎｇＢａｉｙｕｎＰｏｗｄｅｒＭｅｔａｌｌｕｒｇｙＲｅｓｅａｒｃｈＩｎｓｔｉｔｕ...     

The Effect of Sulfur Segregation on the Adherence of the Thermally-Grown Oxide on NiAl—I: Sulfur Segregation on the Metallic Surface of NiAl(001) Single-Crystals and at NiAl(001)/Al2O3 Interfaces

The aim of this study was to improve the understanding of the deleterious effect of sulfur impurities on the adherence of the thermally-grown oxide on the boundary layer in thermal-barrier-coating systems. In Part I, the sulfur segregation on the free surface of NiAl(001) and at different interfaces between metal and transient alumina scales has been characterized by AES, XPS and LEED. The sulfur diffusion coefficient in the alloy has been determined (D = 0.15 exp(–218,000/RT) cm²/s). It is by three orders of magnitude larger than the nickel and aluminum self-diffusion coefficients. It has also been observed that the sulfur de-segregates upon Al enrichment of the metallic surface. The saturation of the metallic surface with an amorphous alumina layer formed at room temperature blocks the segregation of S. However, in the initial stages of oxidation where the transient -alumina grows by cationic transport and inject vacancies at the interface, S segregates at the interface between the alumina thin films and the metallic substrate.     

熔融气化炉内硫的反应机理与分配规律

在实验室模拟了熔融气化炉（ＣＯＲＥＸ）的冶炼过程，通过解剖，研究了炉内硫的反应与分配，得到了预还原矿，熔剂，煤，煤气，炉渣，铁液中硫的变化规律，以及这些变化对最终铁水含硫的影响。     

含共晶碳化物Fe－Cr－Mn合金在高温含硫气氛中的腐蚀研究

对含碳量为０．５０－２．６３％的Ｆｃ－Ｃｒ－Ｍｎ合金在８００℃下含硫混合气氛中进行腐蚀试验．用Ｘ射线物相分析法分析了腐蚀产物种类及其相对含量，现实测定了元素在腐蚀产物中的分布及试样亚表层共晶碳化物的腐蚀行为。结果表明：试验合金比高Ｎｉ耐热钢具有高的抗腐蚀性；合金的腐蚀行为受硫化及氧化腐蚀双重制约，因而使合金的腐蚀增重呈现峰值，随气氛氧化性增强，峰值向低碳方向移动；共晶碳化物具有比金属基体略好的抗腐蚀性。     

XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-bearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S^2- or [S2]^2- to [SO4]^2- ; sulfur in the core is in a reduction state, S^2- or [S2]^2- , but exists in an oxidation state S^6 on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed(sulfides inside, while sulfates outside); the layered structure is found in the grains of the bio-oxidation residue.     

Gold leaching with elemental sulfur in alkaline solutions under oxygen pressure

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣｙａｎｉｄａｔｉｏｎｐｒｏｃｅｓｓ ,ｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｆｆｅｃｔｉｖｅｎｅｓｓａｎｄｌｏｗｏｐｅｒａｔｉｎｇｃｏｓｔ,ａｓａｃｏｎｖｅｎｔｉｏｎａｌｔｅｃｈｎｏｌｏｇｙｆｏｒｇｏｌｄｅｘｔｒａｃｔｉｏｎｆｒｏｍｏｒｅｓ ,ｈａｓｂｅｅｎｕｓｅｄｉｎｉｎｄｕｓｔｒｙｆｏｒｏｖｅｒ 10 0ｙｅａｒｓ .Ｈｏｗｅｖｅｒｔｈｅｃｙａｎｉｄｅｉｓａｈｉｇｈｌｙｔｏｘｉｃｃｈｅｍｉｃａｌ,ａｎｄｃｏｍｍｅｒｃｉａｌｃｙａｎｉｄａｔｉｏｎｐｒｏｃｅｓｓｉｓｌｉｍｉｔｅｄｉｎｔ…     

Effect of alloy grain size and silicon content on the oxidation of austenitic Fe-Cr-Ni-Mn-Si alloys in pure O2

Austenitic Fe-18Cr-20Ni-1.5Mn alloys containing 0, 0.6, and 1.5 wt.% Si were produced both by conventional and rapid solidification processing. The isothermal and cyclic oxidation resistance of the alloys were studied at 900°C in pure O₂ to elucidate the role of alloy microstructure and Si content on oxidation properties. The conventionally-processed, large-grained alloy that contained no silicon formed Fe-rich nodules during oxidation. The nodule formation was effectively eliminated by either reducing the alloy grain size by rapid solidification or by adding Si to the alloy. The lowest weight gains were achieved when a continuous silica layer formed between the alloy and the external chromia scale. The formation of the continuous silica layer required a ombination of fine alloy grain size and high Si content. The presence of S in the alloy was found to be detrimental to oxide scale adherence when the silica layer was continuous.     

红外成像技术在GIS设备检漏中的应用

应用红外成像泄漏检测仪器,采用两种方法对三峡电厂、葛洲坝电厂、溪洛渡电厂、向家坝电厂的GIS设备分别进行了检测。结果表明:大面积无目的普查难以发现泄漏点,而对疑有泄漏的地方进行定位检测,当泄漏量达到一定程度时,可以直观地发现泄漏点。     

Measurements of the isochoric heatc v at the critical point of SF6 under microgravity: Results of the German Spacelab Mission D2

During the Second German Spacelab Mission D2 (April 26 to May 6, 1993) the isochoric specific heatc _v of SF₆ was measured along the critical isochore under microgravity conditions with a newly developed scanning radiation calorimeter. This calorimeter provided the possibility to perform comparable heating and cooling runs with variable ramp rates since the spherical sample cell was heated and cooled only by radiation. During the experimental time of 220 h, 11 heating and cooling runs with different ramp rates were performed in a temperature range ofT–T _c=±6 K. ApproachingT _c by cooling from the homogeneous one-phase region avoided significant temperature and density gradients in the fluid, which would have distorted the integral measurement ofc _v. The inhomogenities introduced by a finite ramp rate were greatly reduced by the fast dynamic temperature propagation (critical speeding up). Thec _v data achieved with slow cooling runs are in remarkably good agreement with the theoretical prediction more than one order of magnitude closer to the critical point than anyc _v measurements done so far. The preliminary value for the critical exponent is 0.107±0.02, and for the amplitude ratio we obtainedA ^–/A ⁺=1.94±0.07. In contrast to the cooling runs, the heating runs showed a strong hysteresis ofc _v. A comparison to 1g measurements is provided.Invited paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, USA.