Advanced Materials Research Vols. 430-432

Abstract: Through out the establishment of heavy rail entity model and the finite element model of straightening for different kinds of heavy rail after the residual stress in straightening investigated . Analysed U75V、U76CrRE、U71Mn and U75VM the four different kinds in 8+1 level straightening of the seven regional deformation area rail head, rail waist, rail base vertical stress distribution rule.

Abstract: Poly (butylenes succinate) (PBS) was synthesized by using1, 4-butanediol and succinate as starting material, titanic acid ester and acetate as catalyst, and tried to improve PBS by changing end-group to carboxyl, hydroxyl and chlorine. The results of GPC showed, molecular weight of four kinds of polymer was all beyond seventy thousand; chemical structure of the polymer was measured by FTIR and nitrogen/sulfur/chlorine elementary analyzer; PBS controlled end-group had better thermal properties by DSC and TG; different end-group had influenced mechanical properties; and biodegradability experiment results showed biodegradable speed of PBS can be controlled by changing their end-group.

Abstract: Two specimens from original 10CrMo910 steel and the steel after running 147000h in high temperature were analyzed in this research by SEM, TEM, XRD and electron probe. The results show that after running 147000h in high temperature the 10CrMo910 steel has changed a lot: 1) The dislocation and subgrain boundary in bainite decreased largely while that in massive ferrite almost disappeared. 2) The strip-shape M3C carbides were nearly dissolved, the granular austenite was gradually transformed into martensite, the fine needle-shape Mo2C carbides coarsened, and granular carbides separated out in massive ferrite. 3) There were large particles of M23C6 carbides in crystal boundary between bainite and ferrite, especially in the boundary of any three phases. And creep voids appeared.

Abstract: In order to understand the effects of geographical provenances of teak on wood properties and improve the quality of afforestation in china, research was carried on wood properties of eight provenances of teak at age 27 in Ledong Country, Hainan Island. The slices revealed that the constructional characteristics from different geographical provenances of teak were very similar. But the effect of geographical provenance on teak wood properties was highly significant. The relationship results for properties of teak showed that properties of most wood species had the obvious relation with basic density, which can be used to guide the selection of the teak provenance in the early planting to improve the quality of teak.

Abstract: This paper presents an analysis of tube inversion under axial compression by a finite element method with the aim of expressing and calculating the axial stress from the stress equilibrium equation. The state of a cylinder under internal stress and the inversion transformation mechanism are then clarified, and verification of the proposed theoretical model is examined.

Abstract: The production of huge rectangular ingots becomes crying needs in the condition of lots of heavy plate mills more than 5m have been in operation. In this paper, we simulate the solidification of 60t Q235 huge rectangular ingot with ProCAST in different cooling conditions such as air cooling, forced air cooling and water cooling. The results show that solidification time in forced air cooling and water cooling shortened than that in air cooling respectively by 0.9 hours and 2.2 hours; The primary fine-grain area is large in the forced air cooling and water cooling. In forced air cooling , we can obtain the largest equiaxial crystal ratio and the minimum columnar crystal ratio; The shrinkage cavity position of the ingot in forced air cooling and water cooling is closer to riser than it is in air cooling, but the volumes of shrinkage cavities respectively increased to a greater extent than in air cooling.

Abstract: Cordierite–mullite composite crucibles were prepared via high-temperature solid-state process by using burn talc, datong soil, knar clay, bentonite, quartz, feldspar and alumina as raw materials, waste porcelain powder as skeletal material. The main influencing factors such as the raw materials radio and calcination temperature were discussed. The microstructure of the sintered sample was analyzed with X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The results show that the optimal prescription was sample II (13.34 wt% of burn talc, 10.496wt% datong soil, 40.65% knar clay, 15.00wt% waste porcelain powder,10.34wt% bentonite, 2.17wt% feldspar, 1.61wt% quartz, and 6.394wt% of alumina). The optimal sintered temperature was 1380°C and the holding time was 3 hours.

Abstract: Using the finite element software ANSYS/LS-DYNA for the universal rolling machine to simulate,research unit of the universal rolling deformation etc, and the use of universal mill for heavy rail rolling to simulate of lead samples, study of both. By comparing experimental results, the results show rolling simulation of laboratory lead samples and finite element simulations of computer are basically the same, use the universal pass, the difference of pressure coefficient for the rail head and rail base and rail back that work on the workpiece at the universal pass is small, deformation of workpiece is uniformity, it ensure the dimensional accuracy of the finished rail on the rail section.

Abstract: The integrated navigation system with GPS/INS can obtain precision navigation accuracy. But the accuracy will reduce sharply with the outage of GPS signal for a long time. In this case, the collaborative navigation will play key role. The method of received signal strength (RSS) is to be proposed in this paper to solve the problem of distance measurement between the reference carriers and unknown carrier. Navigation error data were calculated and simulation analysis of the carrier comparison to the situation with collaborative supporting of reference carriers was processed. At the same time, the Matlab simulation to the carrier with INS was carried on. The analysis results of experimental data showed the navigation accuracy of the carrier with unstable GPS/INS signal being improved about 40 percents with the collaborative aids of the reference carriers. The analysis proved the effectiveness of the collaborative navigation method.

Abstract: Unidirectional freeze-drying method has been tried to prepare biomimetic aligned porous materials (APM) from natural macromolecules such as chitosan, gelatin, alginate, carrageenan, various starches, and their composites. All the porous materials have high porosity and surface area, although the pore morphology varies for different sources of natural macromolecules, composition and concentration of solution, as well as crosslinking degree. The APM has potential applications in bioseparation, biomedical engineering, tissue engineering, food and environmental protection.