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With the example of stress corrosion test of natural gas pipeline steel, the application of Visual Basic (VB) language program in the test will be discussed in the paper. The result shows that different waveforms of VB language design can simulate various forms of applied load of pipeline steel well, and make fluctuant slow strain rate test more accurate and convenient.

Slow strain rate tension tests were carried out in order to investigate effect on new corrosion inhibitor to stress corrosion cracking of prestressed steel wire in simulated concrete pore solution. Indeed, the results suggest that C4H13N3 can form adsorption film on the metal surface, prevent chloride ion erosion. Meanwhile, MoO42- may make the passive film become denser. The synergistic effect of C4H13N3 with MoO42-, can reduce the prestressed steel wire SWRH77B in 3.5%NaCl+ saturated Ca (OH)2 solution stress corrosion sensitivity, prevent stress corrosion cracking effectively.

Based on the SSRT, by simulating different forms of applied loads, the paper conducts the research on the influence and mechanism of action from different waveforms upon the stress corrosion of pipeline steel. Results show that under the given F - SSRT testing condition, and when the fluctuation frequency and fluctuation amplitude are same, the sensitivity of the stress corrosion produced upon X70 pipeline steel is the weakest under the F-SSRT testing condition of superimposed square wave, and is the strongest under the F-SSRT testing condition of superimposed sine wave, which shows that the sensitivity degree of stress corrosion of materials under the F-SSRT with different load waveforms is obviously different.

The failure analysis of the H13 steel hot-forging mould is the main content in the open experiment. The scan electronic microscope and the optical microscope are used to analyze the failure workpiece in this experiment. The over-high quenching temperature, the too low drawing temperature, the insufficient drawing time and frequency, the over-high hardness value are the main reasons of fracture failure of the mould. The work environment of the failure materials, the heat treatment processing, the metallographic analysis, the fracture analysis and the using of test standard are the important aspects which the students should know. The students can learn how to analyze problem and how to solve them from the open experiments which is a good teaching try.

Electrodeposition of ZnS thin film is affected by many factors. The effects of experimental conditions and concentrations of complexing agents on the electrochemical properties of plating solution were investigated. Electrochemical workstation was used to test cyclic voltammetry curves in different situations. According to the oxidation and reduction peaks of the curves, the experimental results showed that the effect of complexing agent was the best, while the ammonia was worst. With the increase of concentration of sodium citrate, reduction peak shifted to the negative part, in the meanwhile plating solution with 30 mmol/L of sodium citrate was the best condition for electrodeposition of ZnS thin film.

Domain reduce methods purpose is to reduce the times of simulation and optimization by decreasing search domain so as to realize the least time-consuming. MLIS (move limit indicator strategy) is one of the common effective methods. After analyzing the drawbacks of the existing optimization problem, propose an MLIS using six indicators with domain reduce method. And next, functional quality, search space, move history, assessment criterion, convergence criterion and constraint conditions of the six indicators are introduced detailedly. Finally, Hesse function example and a design problem with cantilever beam are optimized and simuliated by MLIS. The practices proved that this method has a certain application value and practical meaning in domain reducing.

The straightener of pulse tube refrigerator (PTR) can change gas flow distribution in the tube and improve performance of PTR .In this paper numerical simulation is used to study and optimize the property parameters of straightener with helium as work fluid. The straightener is treated as porous media. The key parameter fk. is defined as the ratio of streamwise and transverse permeabilities. The smallest length of straightener is optimized by changing the value of fk. The result shows that straightener can change gas flow distribution in tube and improve performance of PTR. fk. is bigger, the length of straightener is shorter and streamwise pressure drop is smaller.

The extended finite element method is applied to modeling growth of arbitrary crack with crack surface tractions. Firstly, the extended finite element method is investigated for the stress intensity factor solution of surface traction problems. Secondly, for different water pressure acting on the crack surfaces and different crack length, the variation of the stress intensity factors is investigated. Finally, the process of hydraulic fracturing is simulated with the method. Numerical simulations illustrate that the method can effectively model the fracture problems with surface tractions.