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The condition of the surfaces is of crucial importance for the deuterium permeation through materials. In this work a study of the surface constants for the adsorption (σk1) and release (σk2) of deuterium under different surface conditions on the martensitic steel DIN 1.4914 (MANET) has been carried out. The growth of an oxide surface layer (Cr2O3) of about 25–30 nm in a MANET sample, heat treated in an oxidizing environment, compared to the bare MANET that have a ‘natural' oxide of about 5 nm has provoked a reduction of both the permeation rate and the recombination coefficient (about 3 orders of magnitude). In addition, the permeation governing process has changed from diffusion-limited to surface-limited. The measurements of the permeation rate of deuterium were performed by a gas-phase permeation technique over the temperature range 574–746 K and for deuterium driving pressures in the range from 3 to 105 Pa. 相似文献
14.
The feasibility of a new alloy design concept utilizing the principle of ‘tungsten bronze effect’ is critically evaluated for the development of metallic bipolar plates for proton exchange membrane fuel cell (PEMFC). An austenitic stainless steel (ASS) is modified with W and La to improve the stability of the passive film in an acidic environment as well as to reduce the contact resistance by the tungsten bronze effect. The experimental ASS containing W and La was evaluated in a simulated PEMFC environment of H3PO4 and H2SO4 solutions at 80 °C, and the electrical property was evaluated by performing a contact resistance test. The test results show that the ASS modified with W and La has good passive film stability for corrosion resistance and low contact resistance. The X-ray photoelectron spectroscopy (XPS) analysis clearly suggests the possibility of the tungsten bronze effect from the change in valency state of W6+ to W5+ in the passive film formed on the modified ASS. The feasibility of a new alloy design concept utilizing the ‘tungsten bronze effect’ is well demonstrated; however, more study is highly required for the development of metallic bipolar plates of PEMFC. 相似文献
15.
W. Fischer 《Progress in Organic Coatings》1993,22(1-4):181-193
Corrosion protection of organic coated steel is determined by free corrosion potential measurements and impedance spectroscopy. The results are classified by means of very basic considerations and evaluation figures are developed. These electrochemical data are correlated with the extent of the corrosion for each coating system. The evaluation figures are used for ranking coating systems and this ranking is correlated with the ranking with reference to the results of standardized and exposure tests. 相似文献
16.
介绍了LG55冷轧管机使用Φ7~32mm、Φ50~32mm孔型轧制小直径不锈钢管的工艺特点。试验表明,两种孔型可行,且Φ57~32mm孔型的综合使用效果更好。 相似文献
17.
The generation of surface roughness during slurry erosion-corrosion and its effect on the pitting potential 总被引:1,自引:0,他引:1
Results of experiments performed to isolate the effect of surface roughness generated during slurry erosion-corrosion of 304L stainless steel are presented. Surfaces prepared by grinding to different finishes show that increasing the roughness lowers the pitting potential in chloride solution. Subsequent erosion by an aqueous sand slurry then alters this pitting potential (Ep), as measured in the solution phase alone, in a manner dependent on the initial surface roughness. Surfaces which were initially rougher show a pronounced rise in p after erosion, while those with an initially smoother finish show a fall in Ep after erosion. Measurement of Ep during erosion-corrosion does not fit either process, with values of Ep lower than those predicted from the surface roughness alone. 相似文献
18.
F. Otsubo K. Kishitake T. Akiyama T. Terasaki 《Journal of Thermal Spray Technology》2003,12(4):555-559
It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration
is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped
and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180
paper. A martensite phase is formed in the surface layer of both blasted and scraped specimens. Compressive residual stress
is generated in the blasted specimen and the maximum residual stress is formed at 50–100 μm from the surface. The corrosion
potentials of the blasted specimen and subsequently solution treated specimen are lower than that of the non-blasted specimen.
The passivation current densities of the blasted specimens are higher those of the non-blasted specimen. The blasted specimen
and the subsequently solution treated specimen exhibit rust in 5% sodium chloride (NaCl) solution, while the non-blasted specimen
and ground specimen do not rust in the solution. It is concluded that the deterioration of corrosion resistance of austenitic
stainless steel through blasting is caused by the roughed morphology of the surface. 相似文献
19.
Utilizing the existing properties of steel, a modern technological society has been constructed. While there are over 25,000
worldwide equivalent steels based on manipulating the eutectoid transformation, there exist only a handful of commercial nanostructured
steel alloys based on manipulating the more complex glass devitrification transformation. Thus, research on nanostructured
steels is in its infancy, and many further developments are expected with the demonstrated promise of developing new combinations
of superior properties. In this article, seven enabling metallurgical factors are presented that ultimately allow a variety
of nanostructured steel products to be produced in an ever-increasing array of industrial processing techniques. Additionally,
a case example of the formation of nanostructured steel are given showing how these factors can be harnessed on an industrial
scale. 相似文献
20.
DD—921钢铁常温发黑剂的研制和应用 总被引:4,自引:0,他引:4
研究了钢铁常温发黑过程的成膜机理,各组分之间的作用以及相互之间的影响,着重分析了常温发黑的优缺点,工艺控制参数以及经济性。 相似文献