Based on modified θ projection method, creep experiments were carried out on GH4169 superalloy under different temperature and stress conditions,the creep data under different parameters were obtained and corresponding creep curves were drawn.The modified θ projection method was used to perform nonlinear fitting of the obtained experimental curve,and creep equations related to temperature and stress were established.The creep life curve of GH4169 superalloy is verified by the creep equations,and the results are in good agreement,so as to reach the effect of creep life prediction.

Using the method of qualitative and quantitative combination, the risk identification and pre-risk analysis of CNG filling stations were carried out by using the principle of system safety engineering. And the FLACS software based on computational fluid dynamics was used to simulate the accident situation of the filling station leakage. The influence of different wind speed on the leakage accident and the different ignition position on the explosion accident were studied, so as to provide the data support for the design of the safe distance and the safety barrier to reduce the accident risk. The results showed that the volume of the gas cloud increases rapidly within a few seconds of the beginning of the leakage, but the volume of the gas cloud exploded in a stable state over time; the larger the wind speed was, the farther the diffusion distance of the gas cloud, but the actual dangerous concentration volume gradually decreased; different ignition locations would cause different over-pressure, where the edge of the ignition caused by the explosion over-pressure was greatest and the center ignition produces an explosion over-pressure minimum

 

Failure of heat exchanger at a wash of circulating water factory was analyzed by optical microscope, X-ray fluorescence spectrometer, X-ray diffraction (XRD), electrochemical test analysis method. The results show that chemical composition of heat exchanger didn’t meet the standard of 20# steel. Due to the surface of the vascular bundles scaling there is a serious corrosion. inside surface of tubes exist iron oxide layer which led to the under-deposition corrosion because different concentration of oxygen inside and outside deposition form corrosion battery. Therefore, under-deposit corrosion is the main the main cause of tubes perforation.

The corrosion behavior of X80 pipeline steel in simulated solution of acid soil was investigated using electrochemical measurement and metalloscope. The results show that the microstructure of the base metal is acicular ferrite, the microstructure is uniform and tiny, the distribution is parallel. The microstructure of the weld joint of X80 pipeline steel is characterized by proeutectoid ferrite, acicular ferrite and pearlite, the microstructure is uneven and bigger than base metal. No active-passive transition region is found in polarization curves of both base metal and weld joint. Both corrosion potential and charge transfer resistance of weld joint is lower than the base metal, whereas corrosive current density of the weld joint is greater than the base metal, which indicates that weld joint has a greater tendency to corrosion. The diffusion index of base metal is larger in equivalent circuit, and the corrosion produce film is denser. Corrosion resistance of the weld joint of X80 pipeline steel is lower than the base metal, due to differences in microstructure.

As compared with stainless steel 304 (SS304), polarization curves and electrochemical impedance spectroscopy (EIS) of high nitrogen stainless steel (HNSS) were measured under simulated PEM fuel cell environment. The experimental results show that the natural corrosion current density and the passivation current density of HNSS is 21.7% and 24.5% lower than SS304 respectively, and this illustrates HNSS has better corrosion resistance than SS304；the value of the charge transmission resistance of HNSS is 2.43×103 times larger than SS304, and the dispersion index of HNSS (N=0.899 4) is closer to 1 than SS304 (N=0.844 5), and this indicates that the passive film of HNSS is thicker and smoother than SS304.

 

Electromechanical integrated toroidal drive is a new-style transmission. Based on the theories of toroidal drive and electromagnetics, elastic force and friction are replaced by electromagnetic force, so it is contactless and non-lubriction .For the integration of transimission,driving and control, its structure size becomes smaller, and it is controllable also. Based on the force analysis of planet, space mechanics model was established, driving mechanism was discussed, and output torque formula was developed, the influence factor and influence law were analyzed. The result shows that the output torque is proportional to the factors such as planetary diameter and so on, but the increasing of planet can’t lead to the increasing of output torque.