Alumina-forming austenitic (AFA) heat-resistance steels firstly developed by Yamamoto et al. at Oak Ridge National Laboratory have been reported as a new promising class of steels with potential for use in high temperature applications in recent years. The creep resistance of AFA steels is improved mainly by precipitation strengthening. Besides modifying the typical existing precipitates, i.e. MC and M23C6 type carbides, B2-NiAl and Fe2Nb-type Laves phase, introduction of coherent L12-ordered precipitate is highly desired. L12-ordered phase gamma prime (γ’) is the most important precipitate for high-temperature strengthening in Ni-based superalloys. In the present work, we demonstrate that addition of 2.8 wt. % Cu to an AFA steel promotes the formation of an L12-ordered phase with the dominating elements Ni, Cu and Al. TEM characterization after slow rate tensile tests indicated there were the different precipitation behaviours at 700°C and 750°C. It was revealed that the occurrence of L12-ordered Ni-Cu-Al phase depends on temperature and Ni content. This opens up new opportunities to promote the formation of L12-ordered phase in Fe-based austenitic heat-resistance steels and benefit high-temperature mechanical properties.

Tantalum-doped indium tin oxide films were deposited on glass substrate by co-sputtering with two-targets. Tantalum-doping strengthened the orientation of the (400) plane and resulted in better crystalline structure, larger grain size and lower surface roughness. Due to the better crystallizability of the tantalum-doping films, carrier concentration and the mobility were increased. Tantalum-doping revealed better optical–electrical properties. The environmental effects on electrical properties stability and long-term reliability of tantalum-doped films in NaCl, Na2SO4 and HCl solutions at 25°C were also investigated, which simulated corrosion behavior in marine, industrial and acidic environments. The relative resistance change (△R/R) for tantalum-doped films revealed that the films had the best electrical properties stability and long-term reliability in these aggressive environments. The pre-formation of a protective oxide layer on the surface of the films had an enhancing effect on the corrosion properties.

Activated carbon (AC) was prepared from lignite by microwave heating ZnCl2. The pore structure parameters of AC are characterized by nitrogen adsorption technique. The AC and ruthenium oxide/AC composite are characterized by thermogravimetric analysis and transmission electron microscope. Electrochemical properties of ACs and ruthenium oxide/AC composite electrodes were investigated by cyclic voltammetry and constant current charge–discharge after AC was pre−oxidized by HNO3 solution. The results show that the specific surface area and total pore volume of AC from lignite reaches 1310 m2 g−1 and 0.80 cm3 g−1, respectively. The micropore volume of AC from lignite totals only 12.5%. AC and ruthenium oxide/AC composite electrodes with 5wt.% ruthenium oxide loading show high cycle stability. Compared to pristine AC electrode, specific capacitance of ruthenium/AC composite electrode and energy density of ruthenium/AC capacitor after 100 charge−discharge cycles increases 40.8% and 39.1%, respectively.

The welded joint of a S890QL grade steel pipes containing 1.2% Ni have been prepared to characterize the use performance under high cycle fatigue test. It has been found that the fatigue strength of the welded joint is 290MPa with a fatigue life of more than 10 million cycles, and the obtained Basquin equation is σa=488*(2N)-0.02758 . It is found that the steel exhibits the whole bainite microstructure when the cooling rate is less than 1°C/s. The welded joint is divided into the weld zone, the coarse grain zone, the fine grain zone, the softening zone and the matrix. The fine grain characteristic in the welded area determines the good anti fatigue performance of the investigated steel.