Experiments on the gas protection of porous refractory materials from oxidation and erosion in plasma flows

Summary The possibility is demonstrated of counteracting high-temperature oxidation and erosion of the surface of refractory metals in plasma flows using protective gas films created by a blast through porous walls.We evaluate the orders of magnitude of the relative protective gas consumptions for the required decrease. We describe the apparatus used to test the strength of porous refractory materials in plasma flows.Translated from Poroshkovaya Metallurgiya, No. 4(52), pp. 70–77, April, 1967.     

油气田用Inconel718合金腐蚀性能研究综述

综述了油气田用Inconel 718合金抗均匀腐蚀、点蚀、晶间腐蚀、电偶腐蚀、氢脆和应力腐蚀等常见腐蚀性能,分析了Inconel 718合金耐蚀性能良好的主要原因,着重阐述了Inconel 718合金热处理工艺对各种腐蚀行为的影响,并提供了合理的热处理工艺对应的安全服役环境。最后展望了高温高压含H2S腐蚀环境下Inconel 718合金的选材依据、应用前景,以及Inconel 718合金性能提高的热点和难点。     

Review on corrosion resistance properties of Inconel 718 alloy used in the oil and gas industry

This paper summarizes the corrosion behavior of Inconel 718 alloy,which is used in the oil and gas fields,including its uniform corrosion,pitting,intergranular corrosion,galvanic corrosion,stress corrosion,and hydrogen embrittlement.It also analyzes the main reasons for the good corrosion resistance of Inconel 718 alloy.This paper focuses on the effects of the heat-treatment process on corrosive behavior and provides guidelines for reasonable heat treatments in security service environments.Finally,this paper recommends further studies and applications of Inconel 718 in corrosion environments with high-temperature,high-pressure,and wet H2S.     

Distribution of the heat and current fluxes in gas tungsten arcs

The distribution of heat flux on a water-cooled copper anode as a function of welding process parameters has been determined experimentally following an experimental technique developed previously. The results indicate that arc length is the primary variable governing heat distribution and that the distribution is closely approximated by a gaussian function. The half width of the heat flux is defined by a distribution parameter, σ, which was determined from the experimental data and is expressed as a function of arc length, current, and electrode tip angle. The distribution parameter, σ, increases from 1.5 mm to 3.6 mm as the arc length increases from 2 mm to 9 mm for a 100 A arc. The experimental data also show that arc energy transfer efficiency is greater than 80 pct on the water-cooled anode which is much higher than has been measured in the presence of a molten metal pool. For this reason, it is believed that the distribution of the heat flux and not the magnitude is the most useful information obtained in this study. The effect of helium additions to the argon on the heat distribution is also reported. Formerly Research Assistant, is with the Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA     

Investigations in the field of nontraditional electrochemistry and corrosion of materials carried out by the school of I. N. Frantsevich

The electrochemical theory of high-temperature corrosion resistance developed by I. N. Frantsevich is briefly reviewed, and a comparative study is made of the electrochemical parameters of both the high-temperature oxidation of tungsten and its oxidation in 1 N H₂SO₄. Consideration is given to the principal results of experimental and theoretical studies of the limiting stages of hydrogen cathodic evolution on the surface of metals, semiconductors, and certain binary refractory compounds. Topics included are the catalytic recombination of hydrogen atoms, their electrochemical desorption, the interaction of hydrogen atoms with electrons as disclosed by calorimetric, cyclotron resonance, and EPR methods of investigation. Particular attention is paid to the corrosion of copper and silver coatings on copper parts used in sealed systems containing the decomposition products of polymeric insulation. Weak-current corrosion of contacts, and the electrochemical protection of steel structures in aggressive soils and sea water are also reviewed.Institute of Materials Science, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkova Metallurgiya, Nos. 7/8(380), pp. 107–121, July–August, 1995.     

转炉煤气回收系统的腐蚀与防腐问题探讨

针对转炉煤气设施腐蚀比较严重的问题,通过对煤气腐蚀性成分、腐蚀物样品进行分析,并采用了实验室加速模拟试验、现场挂片试验等多种实验手段对选定的防腐蚀手段的优劣及合理性进行了比较和验证;提出了转炉煤气设施腐蚀防护的综合解决方案.     

海洋环境下的金属材料腐蚀研究进展

对金属材料在海洋环境中的腐蚀规律进行了综述,探讨了温度、溶解氧、盐度、pH值等多种因素对金属材料在海洋环境中腐蚀的影响,总结了近年来国内外金属材料在海洋环境中的腐蚀问题研究现状,并对海洋环境腐蚀问题的研究趋势进行了展望。     

Unique features in the characteristics of friction and wear for materials based on high-speed steel

Translated from Poroshkovaya Metallurgiya, No. 12 (348), pp. 68–71, December, 1991.     

用国产快速开关代替进口快速开关

东北轻合金加工厂用国产快速开关代替进口快速开关，不仅节约了大量外汇，保证了备件的及时供应，而且经济效益也很可观。     

Effect of temperature on the corrosion of some materials in perrhenic acid solutions

Corrosion of some metallic and nonmetallic materials (nickel, copper, iron, glass) in solutions of perrhenic acid HReO₄ (∼345 g/l) is studied in the temperature range 15–30°C. It is demonstrated that this process is limited by diffusion and characterized by the following values of activation energy (kcal/mol): 1.21 for glass; 1.77 for iron; 1.83 for copper, and 2.01 for nickel.