Advanced Materials Research Vols. 284-286

Abstract: SPV50Q steel belongs to high-alloyed steel that is widely used to fabricate storage tank for liquefied petroleum gas. However, it has a great tendency to the problem of environmental cracking under the service condition of LPG containing wet sulfide hydrogen surpassing the lowest allowance for steels. In order to quantitatively evaluate the cracking susceptibility on this steel in the wet H2S environment, the pre-fatigue crack M-WOL specimen stress corrosion cracking tests in three H2S concentrations were performed under the different welding conditions, and in safety performance analysis of equipment, and preventing countermeasure had been proposed. The method could be extended forecasting accident in LPG SCC.

Abstract: [Purpose] To show storage-resistant food internal quality changes such as canned food. [Method] By measuring the time-temperature-gray relational model of thermo-sensitive paper, compare it with the time-temperature-quality movement model of storage-resistant food. [Results] The analysis of the example show that: through controlling the production process and prescription of thermo-sensitive paper, adjusting the dosage of color-producing reagent, enabling the variation rule of gray match with the quality change of storage-resistant food. [Conclusions] Based colorless dyestuff 2-phenyl-3-methyl-6, 6-2 D-amino fluoran and 2, 2-bis (4-hydroxyphenyl) propane color developer thermo-sensitive system, through controlling the production process and prescription of thermo-sensitive paper to show the quality change of storage-resistant food.

Abstract: Working model and the structure in common use for Magneto-Rheological rheometer was investigated based on the former investigation. Then the parallel plate structure under shearing mode was selected. Theoretical calculation for the measurable parameters of Magnetorheological Rheometer was discussed. The drawings for the parts and assemblage of the Magnetorheological Rheometer were devised. And finally the explanation for the Magnetorheological Rheometer was provided.

Abstract: Fe-doped Na_0.5Bi_0.5TiO₃ was successfully synthesized by a hydrothermal method. Magnetic loops measured at room temperature indicate that the magnetism of NBT crystals can be controlled by Fe doping concentration. The magnetism of the Fe-doped Na_0.5Bi_0.5TiO₃ crystals develops from diamagnetism to ferromagnetism on increasing Fe doping concentration from 0 to 60mol %. The results presented in this study may provide an approach to widely exploring more multiferroic materials.

Abstract: By taking high aspect ratio straight wing as the research object, static aerodynamic force and dynamic aerodynamic force are detailed analysed and researched. The flutter speed of panel derived from Unsteady Theory and Theory.

Abstract: Based on the research of the theory and the experiment of EMD and Intrinsic Modal Energy Entropy，the vibration signal of a rolling bearing in a Blowing Machine of a certain factory was measured when working. Then the signal was decomposed by EMD, its Intrinsic Modal Energy Entropy was calculated and used as fault feature. Finally, using a Support Vector Classification System, a satisfied effect of fault diagnosis of a rolling bearing in a Blowing Machine was got. The experiment had confirmed that the method was advanced, reliable and practical. A new method was provided for fault diagnosis of rolling bearings in some Blowing Machines.

Abstract: Theoretical three-dimensional Gaussian heat distribution model of the complex heat flow and plasma properties of cutting plasma torches have been developed. For cutting metallic plates, plasma torches must produce a narrow supersonic plasma jet with enough energy and momentum densities to melt, vaporize, and remove the metal from the impingement region. Our model allows us to study the details of the heat distribution and to make predictions on pick temperature development on metal surface, heat transfer to the work piece, force i.e. the forces acting on the melt (aerodynamic drag, gravity, viscosity and surface tension) during plasma arc cutting, the main forces acting on the melt is believed to be the aerodynamic drag force and the gravity is significant only for thick metal plates. With the help of these assumptions and diameter of Gaussian heat source’s volume, diameter of nozzle has been calculated for thin work piece. A good agreement is found between the model results and the available experimental data.

Abstract: In Submerged Arc Welding process involves critical set of variables which are needed to control. An attempt has been made in this paper to find out- the influence of the heat input and bead volume on HAZ Hardness for Submerged Arc Welding Process of Mild steel plates. Mild steel plates are welded by changing input variables (current, voltage, travel speed, i.e. heat input) and Rockwell hardness no. has been observed on welded portion and at the zone adjacent to the welded portion. A detailed analysis of the microstructure changes is carried out to understand the HAZ softening phenomenon.

Abstract: An attempt has been made in this paper to develop a appropriate model for predicting the output responses of Submerged Arc Welding (SAW) process with the help of neural network technique. Also a mathematical model has been developed to study the effects of input variable (i.e. current, voltage, travel speed) on output responses (i.e. reinforcement height, weld bead width, metal deposition rate). SAW process has been chosen for this application because of the complex set of variables involved in the process as well as its significant application in the manufacturing of critical equipments which have a lot of economic and social implications. Under this study the neural network model is trained according to the actual inputs and outputs. When the training is completed then the desired inputs are given to the model and it gives the estimated output value. And according to this we can also estimate the error between the actual and predicted results. Side by side accurecy of mathematical model has been checked.

Abstract: Submerged Arc Welding process (SAW) is a high quality, very high deposition rate welding process. It has lot of social and economical implecations.This paper makes an attempt to uncover an important area on studies of temperature distribution during submerged arc welding because this may pave the way for application of microstructure modeling, thermal stress analysis, residual stress/distribution and welding process simulation. Prediction of temperature variation of entire plates during welding through an analytical solution is derived from the transient multi dimensional heat conduction of semi infinite plate. The heat input that is applied on the plate is exactly same amount of heat lost for electric arc, which is assumed to be a moving double conical heat source with Gaussian distribution for Submerged Arc Welding process. Good agreement between predicted and experimental results has been achieved.