Explore the vast range of titles available.

To shorten the time required for the pickling process and to enhance the quality of ferritic stainless steel plates,the effects of oxidants including hydrogen peroxide（H2O2）,potassium permanganate（KMnO4）,and potassium chlorate（KClO3）on the pickling behavior in HCl-based electrolyte as well as the surface quality of hot-rolled and blasted 430 stainless steel（430-SS）were studied.Experiments were conducted using mass-loss tests,microstructure analyses,potentiodynamic polarization curves,and electrochemical impedance spectroscopy measurements.The results showed that the addition of oxidants substantially accelerated the pickling process of 430-SS by enhancing the cathodic reaction rate and reducing the charge transfer resistance.In electrolytes comprising 5-8mass% HCl at a temperature of 40-60 ℃ and at the same concentration within the range from 0to 2mass%,H2O2 was demonstrated to be superior to KMnO4 and KClO3in accelerating the pickling process.The surface quality of 430-SS pickled in the presence of H2O2 was better than those of specimens pickled in the presence of KMnO4 and KClO3 when the removal of the oxide layer,intergranular corrosion,and surface roughness were collectively considered.When 1mass% H2O2 was added,the mass loss rate of 430-SS was increased by 629%and no residual oxide layer or intergranular corrosion was observed on the surface of the steel;in addition,the roughness was only 1.7μm.H2O2 was determined to be a better oxidant than KMnO4 and KClO3 when the pickling process,surface quality,solution recycling,and environment protection were considered as a whole.

The precipitation kinetics of secondary phases in two austeno-ferritic lean duplex stainless steels（lean DSS）were examined after aging the materials at 800 ℃.Owing to the instability of ferrite,all DSS are known to be sensitive to solid-state phase transformations in the critical temperature range 600-1,000 ℃ and different secondary phases may form,depending on composition and microstructure.The performed thermodynamic simulations revealed the proneness to the precipitation of such phases also have been done in lean DSS,but only information on the equilibrium microstructures were achieved.Therefore,the materials were aged at various times,in order to verify the simulations and determine the precipitation kinetics.The occurred structural modifications were observed and quantified by scanning electron microscope and X-ray diffraction measurements,determining phase type,composition and volumetric fraction.At 800 ℃,grade 2101 was found to be only affected by Cr_2N nitrides precipitation,whereas a significant amount of σ-phase was found to form in LDX 2404 for treatment longer than 1 h,almost totally replacing ferrite after 50 h.Up to now,the intermetallic σ-phase has been observed only in the high alloyed DSS,and the unexpected precipitation in grade 2404 highlighted that the increased content of molybdenum in this steel might be considered as determinant for the formation.

Refining process of 430 stainless steel in AOD （argon oxygen decarburization） was simulated under the experimental condition. Al was chosen as deoxidizer, Mg-Al alloy was added in process of refining, and slag used in oxidation period of AOD was chosen in the experiments. The variation of total oxygen content, the size, morphology and composition of inclusions in refining process and the mechanical properties, pitting corrosion resistance of final samples were studied. The results show that no obvious differences in total oxygen content were observed among all the experiments. Neither chain nor cluster Al_2O_3 inclusions were found in refining process of experiments treated by Mg-Al alloys, the average size of inclusions in the steel treated by Mg-Al alloys was less than that of inclusions in steel not treated by Mg-Al alloy. 430 stainless steel treated by Mg-Al alloy shows better tensile strength, yield strength, and pitting resistance than that in the contrast experiment.

To solve the problems of poor forming and easy adhesion of the stainless steel,Cu alloyed layer on the stainless steels was prepared by the double glow plasma surface alloying technique.The experimentalresults indicated that the supersaturated copper dispersedly precipitated in grain interior and crystalboundaries and formed the vermicular structure.The tribologicaltests indicated that the friction coefficient of the Cu alloyed layer was lower than that of the stainless steels.The wear rate of stainless steelin the presence of Cu alloyed layer was approximately 2-fold lower than that in the absence of the alloyed layer.The results of the incrementalforming indicated that the ploughing phenomenon was not observed on the stainless steelin the presence of Cu alloyed layer during the incrementalforming,while the stainless steelpresented the deep ploughing.Therefore,Cu alloyed layer on stainless steelexhibited excellent self-lubrication and forming properties.

Machining of micro holes with micro electrochemical machining (micro ECM) process has been carried out with an indigenously developed set up. This paper describes relevant problems and solutions for the circular micro holes machining process on 304 stainless steel sheets with 60 μm thickness using high speed steel cylindrical tool of diameter 500 μm and using dilute H 2 SO 4 as electrolyte. The taper angle variation of the machined hole is analyzed and reported for different experimental setting parameters. The minimum value of the taper angle of machined holes is achieved at the parameter setting of 0.4 mol/L H 2 SO 4 , 700 kHz, 600 ns and 21 V, for stainless steel sheets and HSS tool.

An innovative application of laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） technique in illustrating elemental distributions on stainless steel sheets was presented. The technique proved to be a systematic and accurate ap- proach in producing visual images or maps of elemental distributions at cross-sectional surface of a stainless steel sheet. Two stain- less steel sheets served as research objects： 3 mm×l 300 mm hot-rolled stainless steel plate and 1 mm×l 260 mm cold-rolled plate. The cross-sectional surfaces of the two samples at 1/4 position along the width direction were scanned （raster area -44 mm2 and 11 mm2） with a focused laser beam （wavelength 213 nm, diameter of laser crater 100 μm, and laser power 1.6 mJ） in a laser abla- tion chamber. The laser ablation system was coupled to a quadrupole ICP-MS, which made the detection of ion intensities of 27A1＋, 44Ca＋, 47Ti-, 55Mn＋ and 56Fe＋ within an area of interest possible. One-dimensional （ID） content line distribution maps and two- dimensional （2D） contour maps for specific positions or areas were plotted to indicate the element distribution of a target area with high accuracy. Statistic method was used to analyze the acquired data by calculating median contents, maximum segregation, sta- tistic segregation and content-frequency distribution.

The influence of flux cored arc welding （FCAW） process parameters such as welding current, travel speed, voltage and CO2 shielding gas flow rate on bowing distortion of 409M ferritic stainless steel sheets of 2 mm in thickness was discussed. The bowing distortions of the welded plates were measured using a simple device called profile tracer. An experimental regression equation was developed to predict the bowing distortion and with this equation, it is easy to select optimized process parameters to achieve minimum bowing distortion. It is revealed that the FCAW process parameters have significant influence on bead profile and the bowing distortion.

Butt joining of 5A02 aluminum alloy to 304 stainless steel sheets was conducted using gas tungsten arc welding process with Al-12%Si （wt.%, the same below） and Zn-15%Al flux-cored filler wires. The effects of gap width and groove in steel side on the microstructure and tensile strength of the resultant joints were investigated. For the joint made with 0 mm-wide gap and without groove in steel side, severe incomplete brazing zone occurred along the steel side and bottom surfaces, and consequently seriously deteriorated the joint strength. However, presetting 1.5 mm-wide gap or with groove in steel side could promote the wetting of molten filler metal on the laying surfaces, and then significantly enhance the resultant joint strength. Moreover, post-weld heat treatment could further improve the tensile strength of the joints. During tensile testing, the specimens from the joints made with AI-12%Si flux-cored filler wire fractured through the weld or interracial layer, but those from the heat-treated joints made with Zn-15%AI flux-cored filler wire fractured in the aluminum base metal.

A multipoint excitation experiment system of the 1Cr18Ni9 steel plate-pipe network as the main vibration body was established,which used transient flow produced by the wave exciter to excite the 1Cr18Ni9 steel plate-pipe network to vibrate.The experimental results show that the 1Cr18Ni9 steel plate vibrates in three dimensions.The vibrations of the particles of the steel plate distributing along the pipe＇s axial have phase differences and take place near the cylinder side first.Therefore,it is a multipoint vibration mode.The amplitude of the 1Cr18Ni9 steel plate increases as the system pressure increases and decreases as the wave exciter＇s frequency decreases.The vibration intensity of the particles of the 1Cr18Ni9 steel plate close to the cylinder is the strongest and the amplitude is the highest in Y direction at a given system frequency.The vibration intensity of the particles close to the wave exciter is the strongest and the amplitude is the smallest in Z direction at a given system pressure.