Formation of amorphous Fe-Cr-Mo-8P-2C coatings by the high velocity oxy-fuel process

Alloy powders of Fe-10%Cr-8%P-2%C(10Cr), Fe-20%Cr-8%P-2%C(20Cr), and Fe-10%Cr-10%Mo-8%P-2%C(10Mo) compositions (in mass%) were sprayed by the high velocity oxy-fuel (HVOF) process under different conditions. The as-sprayed coatings of 10Mo alloy were composed of only an amorphous phase under all the spray conditions, while the as-sprayed coatings of the 10Cr and 20Cr alloys consisted of an amorphous phase with a small amount of crystalline material. The volume fraction of the crystalline material increased slightly with the rise of the flame temperature. The hardnesses of the as-sprayed coatings of the 10Cr and 20Cr alloys were 600 to 700 DPN, respectively, while the 10Mo coating composed of an amorphous phase revealed 560 DPN. The corrosion resistance of the as-sprayed coating of the 10Mo alloy was the best among three amorphous coatings and also superior to the nickel-base self-fluxing alloy and SUS316L stainless steel coatings in 1N H₂SO₄ and 1N HCl solutions.     

The fluctuations in slag foam under dynamic conditions

In the present article, slag foaming phenomenon under dynamic conditions is critically analyzed on the basis of the results of high-temperature X-ray image analysis experiments. The results indicate that the mismatch between the gas generation rate and gas escape rate has a serious impact on the foam height. This mismatch is attributed to the chemical reaction rate, which has to be considered in modeling slag foaming under dynamic conditions. The results further imply that a critical ratio of bubble size/crucible size exists, where wall effects are likely to become prominent.     

Structure and decomposition of A13-type phase in rapidly solidified high-carbon Cr-Si iron alloy

A high-carbon iron alloy containing chromium and silicon was rapidly solidified into a ribbon. The structure consisted of a single phase which was confirmed to be A13-type structure,ψ phase, from X-ray diffraction and transmission electron microscopy. The pair distribution functions showed that theψ phase is of looser atom packing compared with austenite (γ), ε, and χ phases and rather close to an iron-base amorphous phase in regard to local atom arrangement. Decomposition of the ψ phase took place in two stages: the decomposition of theψ phase to ferrite (and/or MS-I) plus MS-II phase at 700 to 800 K and the transformation of the MS-II phase to M₇C₃ carbide around 1000 K. Thus, it was found that theψ phase structure had an atom configuration close to an iron-base amorphous phase, and the decomposition behavior was also similar to that of the amorphous phase.     

Social Camera给光影来点人情味

在我们的生活中,全世界每天几乎会有5亿张图片被分享到社交网络中,与前几年相比成数倍比例增长,而人们的拍照行为也愈发带有浓厚的社交属性,这样的用户行为和需求市场让一些可以联网完成分享的图像设备应运而成。你是艺术家？还是社交帝？从今天开始,给你的光影来点人情味！     

时尚与生活的排列组合

你的社交软件曾经被nice刷过屏吗？这款国内第一个品牌滤镜APP以简约的标签功能让潮人们掀起了分享私物的风潮,不同于以往的炫富和晒物,nice的分享带有浓厚的时尚氛围和文艺气息,它让每个人都可以随手就对时尚和生活做出简单的排列组合。     

Effect of manganese on the recrystallization texture of P-containing low-carbon steel sheet

The effect of manganese on the development of 111 recrystallization textures of P-containing low-carbon Al-killed steel sheet has been investigated. A proper combination of phosphorus and manganese content in steel gave a strong 111 texture through a simulated box annealing cycle. The experimental data suggest that 111 recrystallization textures could be developed providing that the steels contained both high manganese and phosphorus. Phosphorus in steel was useful in enhancing the uniform dispersion of precipitates such as (FeMn)₃C and A1N. This might be attributed to softening the possible interaction between manganese and carbon or nitrogen atoms by the addition of phosphorus which is regarded as a repulsive element for carbon or nitrogen. The 0.2 pct P-1.2 pct Mn Al-killed steel sheet tested had a highr- value of 2.0 through the precipitates effect and a high strength of 430 MPa through the effect of a solid solution hardening due to phosphorus.     

Decolorization of heat-treatment liquor of waste sludge by a bioreactor using polyurethane foam-immobilized white rot fungus equipped with an ultramembrane filtration unit

A bench-scale bioreactor using immobilized fungal cells equipped with an ultramembrane filtration unit was developed as a means of decolorizing brown color components (melanoidins) arising from the heat-treatment liquor (HTL) of waste sludge. Artificial HTL containing 4200 color units of synthetic melanoidin supplemented with 1000 mg/l ethanol was first subjected to decolorization by the fungus Coriolus hirsutus IFO4917 immobilized onto polyurethane foam cubes. Then, the resultant biologically treated HTL was subjected to ultrafiltration to obtain the permeate (filtrate) as the effluent. The retentate (concentrate) of the filtration unit, containing the remaining melanoidin of high molecular weight and extracellular decolorizing enzymes, was returned to the fungal bioreactor to allow further decolorization. This system was operated in a sequencing batch mode under nonsterile conditions. Contamination of the bioreactor with air/water-born microbes markedly lowered the decolorization efficiency. However, this problem was solved by heating the returned concentrate at 50 degrees C for 10 min. Under the almost stable condition of a hydraulic retention time of 2 d in a 1-d cycle sequencing batch mode, about 70% decolorization was routinely achieved using the entire system (bioreactor + ultrafiltration), while the contribution of the fungal bioreactor alone to the decolorization was about 45%.