Advanced Materials Research Vols. 287-290

Abstract: According to the requirement of the pot scaleboard of Coke Dry Quenching, high content of aluminium heat resisting alloy was developed.Through changing the content of carbon,boron and titanium,the best compounding of the heat resisting alloy was Fe-8Al-1B-5Cr-0.3C-0.5Ti.The microstructure of this kind of alloy was observed and analyzed with optical microscope.It also had good performance of oxidation resistance,abrasion resistance and thermal fatigue resistance,it was suitable for using as pot scaleboard of CDQ.

Abstract: The content SBS plays an important role on the performances of its modified asphalt. Traditional methods which were based on the differences of performances and molecular weight couldn’t quantify SBS content accurately. On the basis of FTIR analysis of SBS, the characteristic peak combination of modified asphalt that could be possibly used for quantitative analysis was summarized. According to theory of Lambert-Beer’s law, a relationship of absorbance ratio and content of mass was deduced. Considering the physical property of SBS polymer modified asphalt and coefficient of variation of specimens, the standard method to prepare SBS polymer modified asphalt for FTIR test was established. Then, regression coefficients were tested for significances combining with theoretical equation and linear programming method, the optimum characteristic peak ratio combination for quantification was designated. Finally, a reasonably accurate and precise method to quantify SBS content is achieved, and the author expected the research could provide the guidance for quantification of polymer content in polymer modified asphalt through this paper.

Abstract: High strength steel ZJ700MC with yield strength grade of 700 MPa was successfully developed by Ti micro-alloyed technology in the EAF-CSP line at Zhujiang Steel. The composition design, smelting process, continuous casting and rolling process of the steel, as well as the mechanical properties of the hot-rolled product are introduced in the paper. An analysis on the strengthening mechanism of the high strength steel shows that the enhanced strength and toughness of the steel were caused by the refinement of ferrite grain and the precipitation strengthening of TiC.

Abstract: This work presents results on the influence of fluoride ions on the behavior of layers whose main component is the phase TiAl_0.3Si_1.7 (called t2 phase), formed on TiAl6V4 substrate. Layers were prepared in AlSi20 melt at 650 ° C for 60 min. Potentiodynamic curves were measured in a chloride solution with 0 and 5000 ppm fluoride. Layer were shifted corrosion potential to more negative values and at the some time reduce the corrosion current density (Im). Values of Im are in the potential range of 300 – 1500 mV (SCE) for TiAl6V4 with Ti-Al-Si layers significantly lower in comparison with Im values found for TiAl6V4 in chloride solution containing 5000 F^-. The electrochemical tests showed that Ti-Al-Si layer had marked positive effect on corrosion resistance of TiAl6V4 alloys in aggressive environment with high content of F^-.

Abstract: This paper reports a CFD modeling study on the flow of gases in an electroslag furnace during Protective Gas Electroslag Remelting(PESR) process by a commercial code FLUENT. The Realizable k−ε turbulence model, Do radiation model and Mixture model are amply used in FLUENT code to compute the flow of gases in the furnace under different argon gas flow, and the influence of argon gas flow on air volume fraction in the furnace is obtained. Finally, a suited suggestion on argon gas flow during PESR process is presented.

Abstract: In order to optimize the casting methods of zinc alloy, which was the replacement of copper alloy materials in the future, we tried our best to improve the solidified form and mechanical properties of zinc alloy casting quality. From the experimental conditions on the existing basis, in the zinc alloy solidifying process, the pressure values ranging from 0.1 ~ 1.0Mpa nitrogen stress management were carried out on alloy solidification .After the cooling ,we had the casting sample comparison macro observed and tensile experimental data analyzed. The results showed that: when the pressure was increased to 1.0Mpa, the macro-organization of the zinc alloy achieved the best, and the degree of shrinkage and pores on the outer surface of the metal were smallest. The mold surface was more smooth, and the number of stomata reduced . The quality of the internal organization could be preliminarily judged by the analysis and observation on the zinc alloy appearance.

Abstract: Mixing the composite phase change material (CPCM) to asphalt mixture is a new way to solve the worldwide problem of the low-temperature cracking and high temperature rutting of the asphalt pavement. Asphalt mixture with CPCM can remain in the ideal working temperature range for a relatively long time. This paper analyzes the influence of the contents of CPCM on its road performance by laboratory testing. The study shows that mixing CPCM to asphalt mixture had little effect to the optimal asphalt content. For CPCM prepared by polymer shape-stabilized method, the high-temperature stability and the water stability of asphalt mixture increases firstly and then decreases the low-temperature anti-cracking stability decreases firstly and then increases with the increasing of CPCM. For CPCM prepared by carrier-adsorbed packaging process, the high-temperature stability decreases, low-temperature anti-cracking stability decreases firstly and then increases, the water stability increases firstly and then decreases with increasing of CPCM. The results indicate that CPCM has significant influences on its road performance. The optimal content of CPCM is around 0.3%.

Abstract: Experiments were carried out to study such basic properties as workability and strength of masonry cement mortar affected by mass content of cement equally replaced by stone powder. The mortar was designed in strength grade of M20 with three kinds of mix proportions, three replacing ratios of cement by stone powder. The results show that part of cement equally replaced by stone powder irregularly influences consistency and layering of fresh mortar but still brings fresh mortar into better workability; the optimum mass content of cement equally replaced by stone powder relates to the water to binder ratio of mortar, which are 5 %, 10 % and 15 % successively corresponding with 1.0, 0.9 and 0.8 water to binder ratio. Comprehensively concerned about the ratio of bending to compressive strengths of mortar, the referenced mix proportions of mortar with stone powder are proposed for application in practices.

Abstract: Experiments were carried out to investigate such basic properties as workability and strength of masonry cement mortar affected by mass content of polypropylene fiber. The results show that proper mass content of polypropylene fiber is helpful for effectively adjusting consistency and layering to bring better workability of fresh mortar, the relative higher bending strength of mortar can be got by admixing reasonable mass content of polypropylene fiber while slight improved compressive strength reaches. The relationships of water to cement ratio and mass content of polypropylene fiber in affecting these basic properties of masonry mortar are analyzed, which can be as reference for selecting optimum water to binder ratio and mass content of polypropylene fiber in practices.

Abstract: The aim of this study was to study the effect of curing period and cement content of the specimen on flexural strength and flexural modulus of elasticity of cement stabilized aggregate. Four specimen curing periods (7 d, 14 d, 28 d and 60 d) and four different cement contents (4%, 5%, 6% and 7%) were used. The results indicate that the flexural strength and flexural modulus of elasticity of cement stabilized aggregate are increasing with the increase of specimen curing period. Besides, with the increase of cement content, there is a tendency to increase both in the flexural strength and flexural modulus of elasticity of cement stabilized aggregate. The actual cement content should be chosen according to the actual condition of the project.