In one aspect, an oxygenated hierarchically porous carbon (an “O-HPC”) is provided, the O-HPC comprising: a hierarchically porous carbon (an “HPC”), the HPC comprising a surface, the surface comprising: (A) first order pores having an average diameter of between about 1 μm and about 10 μm; and (B) walls separating the first order pores, the walls comprising: (1) second order pores having a peak diameter between about 7 nm and about 130 nm; and (2) third order pores having an average diameter of less than about 4 nm, wherein at least a portion of the HPC surface has been subjected to O.sub.2 plasma to oxygenate and induce a negative charge to the surface. In one aspect, the O-HPC further comprises metal nanoparticles dispersed within the first, second, and third order pores. Methods for making and using the metal nanoparticle-impregnated O-HPCs are also provided.

A grain-oriented electrical steel sheet includes: a steel sheet and optionally an insulation coating formed on the steel sheet, in which, in a case where a heat treatment of performing retention at 800° C. for 2 hours is performed, regarding a time-magnetostriction waveform (t−λ waveform) when magnetized to 1.7 T, a peak value of a difference waveform obtained by subtracting the time-magnetostriction waveform after the heat treatment from the time-magnetostriction waveform before the heat treatment is 0.01×10.sup.−6 or more and 0.20×10.sup.−6 or less, and a difference obtained by subtracting an iron, loss before the heat treatment from an iron loss after the heat treatment is 0.03 W/kg or more and 0.17 W/kg or less.

A method for refining magnetic domains of a grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes: a step of preparing a grain-oriented electrical steel sheet; and a step of forming a groove by irradiating a quasi-continuous laser beam of which a duty is from 98.0 to 99.9% on a surface of the grain-oriented electrical steel sheet.

A method for processing corrosion resistant austenitic stainless steel includes: preparing a workpiece made of austenitic stainless steel; and applying compressive residual stress to a surface layer of the workpiece without subjecting the surface layer to plastic working.

To provide a grain-oriented electrical steel sheet that can achieve both sufficiently low transformer core loss and sufficiently low noise. Disclosed is a grain-oriented electrical steel sheet having a tension coating on a surface thereof and subjected to magnetic domain refining treatment by generating linear closure domains extending in a direction within 30° of a transverse direction, in which an average interval L between adjacent closure domains is 15 mm or less, a depth ratio r.sub.d of a depth of the closure domains to a sheet thickness, calculated by a predetermined formula, is 35% or more, and a volume fraction r.sub.v of the closure domains, calculated by a predetermined formula, is 0.30% or more and 3.0% or less, and an area ratio r.sub.s of the closure domains, calculated by a predetermined formula, is 0.50% or more and 4.0% or less.

A laser shock strengthening method for small-hole components (4) with different thicknesses. In the method, different technological parameters are used for laser shock strengthening of the small-hole components (4) with different thicknesses, statistical analysis is conducted after a large number of tests to obtain an empirical formula; the empirical formula is a relational expression AA of the power density and the thicknesses of the small-hole component (4). The power density of laser shock strengthening of the small-hole components (4) with different thicknesses can be determined according to the relational expression; and a method for selecting and determining related technological parameters is provided. According to the method, after the small-hole components (4) with different thicknesses are subjected to laser shock strengthening by using a proper technology, reasonable residual compressive stress distribution can be obtained, a good strengthening effect can be achieved, effective shock quality control can be conducted on the components, and workpiece deformation is controlled while guaranteeing the fatigue life of the small-hole components (4).

A method includes producing a functional structure on an aluminum surface with a local laser treatment of an aluminum surface. The local laser treatment is carried out with a pulsed laser system having a pulse duration of from 10 ns to 100 ns. The average power of the pulsed laser system is less than 5 kW.

A multi-track laser beam process for surface hardening a low-carbon and low manganese steel. The process includes providing cold rolled close annealed (CRCA) steel sheets having in weight percentage, C: 0.03-0.07, Mn: 0.15-0.25 or 1.4, S: 0.005-0.009, P: 0.009-0.014, Si: 0.005-0.02, Al: 0.04, V: 0.001, Nb: 0.001, and Ti: 0.002 and heating the surface of the steel sheet to an austenizing temperature using a multi-track laser beam, where, upon cooling, phase transformation of the initial microstructure to a harder dual phase structure occurs. The surface temperature of the steel sheet may be controlled based on a comparison of the on-line surface temperature effect with pre-stored data representing the desired surface temperature effect to eliminate any possibility of melting the sheet. The development of the desired microstructure of the sheet, including measurement of the hardness level and the fraction of different phases, may be periodically reviewed.

The production method of the novel austenitic stainless steel kitchen knives and the low-carbon high-chromium martensitic alloy powder of the present invention include providing an austenitic stainless steel knife body. It cladding low-carbon high-chromium martensitic alloy powder on the austenitic stainless steel cutter body through high-frequency density laser pulse cladding process, tempering treatment, cutter face grinding, end face grinding, and edge processing; The invention adopts an austenitic stainless steel cutter body, and then adopts a high-frequency density laser pulsation cladding process to make a low-carbon high-chromium martensitic stainless steel at the cutting edge by plasma electrofusion.

A grain-oriented electrical steel sheet according to an embodiment of the present invention includes: a groove on a line formed on one surface of an electrical steel sheet in a direction crossing a rolling direction; and a thermal shock portion on a line formed on one surface of the electrical steel sheet in the direction crossing the rolling direction, wherein a distance between the groove and the thermal shock portion is 1 mm or less.