Described in the article are corrosion and corrosion prevention concerning the straight welded-pipes, including the corrosion process of the pipe in the soil, several corrosional behaviours and relevant countermeasures against the said corrosion effect such as metallic coating, coating and electrochemical protective methods.
THE EFFECT OF METAL COAT GRAPHITE TUBE ON DETERMINATION OF TRACE AMOUNTS OF CADMIUM IN BIOLOGICAL SAMPLES BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY
The article makes research on the preparation of thelow platinum complex oxide catalyst containing base metal, and disc-usses the effect of a different metal coat, two metal oxide coat andthe change of supporter constituents on catalytic activity, etc.
The experimental results show that the performances of the improved ceramic wall flow filter increase and the ceramic wall flow filter of metal coat exhibit excellent and particular performances.
After treating the sample surfaces by sandblasting, the different active metallic coatings ofzinc or aluminum on different samples were obtained by the method of arc spray, therefore thethickness of the coatings was 0.100mm, 0.200mm and 0.300mm, respectively.
The cavitation erosion resistant materials in hydrulic machinery are reviewed. The state of the art in the research and application of new materials with cavitation erosion resistance,including shape memory alloys,work-hardening alloys(Ni_3Al,Ti-based alloys),metallic coatings,nonmetallic coatings,etc,is summarized. The new materials in the future are prospected.
Some practical measuring methods for determining the residual stresses in metallic coatings were reviewed. The testing principles and application status of bending method,hole drilling method,X-ray diffraction method,neutron diffraction method and raman spectrum method were mainly introduced.
Considering the urgent need for methods of resistance to wet H2S stress corrosion cracking (SSCC) during petrochemical production, this thesis, with a view to isolate substrate from the corrosives, introduced arc spraying metallic coatings as a method resistant to SSCC.
It is shown that tearing the coating off occurs most probably in the plane of the minimum coating's cross-section rather than the metal/coating interface.
The ionization of sputtered aluminum atoms in the plasma of a microwave ECR discharge intended for metal coating of submicron-size structures in microelectronics is studied.
This phenomenon is explained by the fact that the debonding metal coating uncovers not the surface of the pure polymer but a certain modified layer, which has a higher elastic modulus than the pure polymer.