Disclosed is a grain-oriented electrical steel sheet exhibiting low hysteresis loss and low coercive force, in which an increase in hysteresis loss due to laser irradiation or electron beam irradiation, which has been a conventional concern, is effectively inhibited. The grain-oriented electrical steel sheet has closure domain regions (X) formed to divide the magnetic domains in a rolling direction, from one end to the other in the width direction of the steel sheet, provided that Expression (1) is satisfied:
(500t80)s+230w(500t80)s+330 Expression (1),
where t represents a sheet thickness (mm); w represents a smaller one of the widths (m) of the regions measured on the front and rear surfaces of the steel sheet, respectively, by using a Bitter method; and s represents an average number of the regions present within one crystal grain.

Disclosed is a grain-oriented electrical steel sheet exhibiting low hysteresis loss and low coercive force, in which an increase in hysteresis loss due to laser irradiation or electron beam irradiation, which has been a conventional concern, is effectively inhibited. The grain-oriented electrical steel sheet has closure domain regions (X) formed to divide the magnetic domains in a rolling direction, from one end to the other in the width direction of the steel sheet, provided that Expression (1) is satisfied:
(500t80)s+230w(500t80)s+330 Expression (1),
where t represents a sheet thickness (mm); w represents a smaller one of the widths (m) of the regions measured on the front and rear surfaces of the steel sheet, respectively, by using a Bitter method; and s represents an average number of the regions present within one crystal grain.

A grain-oriented electrical steel sheet to which electron beam irradiation is applied, has a film and a thickness of t (mm), wherein no rust is produced on a surface of the steel sheet after a humidity cabinet test lasting 48 hours at a temperature of 50 C. in an atmosphere of 98% humidity, and iron loss W.sub.17/50 after the electron beam irradiation is reduced by at least (500 t.sup.2+200 t6.5) % of the iron loss W.sub.17/50 before the electron beam irradiation and is (5 t.sup.22 t+1.065) W/kg or less.

A grain-oriented electrical steel sheet to which electron beam irradiation is applied, has a film and a thickness of t (mm), wherein no rust is produced on a surface of the steel sheet after a humidity cabinet test lasting 48 hours at a temperature of 50 C. in an atmosphere of 98% humidity, and iron loss W.sub.17/50 after the electron beam irradiation is reduced by at least (500 t.sup.2+200 t6.5) % of the iron loss W.sub.17/50 before the electron beam irradiation and is (5 t.sup.22 t+1.065) W/kg or less.

A grain-oriented electrical steel sheet allows for manufacture of a transformer that exhibits, when the steel sheet is applied to an iron core thereof, extremely low iron loss and extremely low noise properties, makes highly efficient use of energy, and can be used in various environments. The grain-oriented electrical steel sheet has a strain distribution in regions where closure domains are formed, when observed in a cross section in the rolling direction, with a maximum tensile strain in a sheet thickness direction being 0.45% or less, and with a maximum tensile strain t (%) and a maximum compressive strain c (%) in the rolling direction satisfying Expression (1):
t+0.06t+c0.35(1).

A grain-oriented electrical steel sheet allows for manufacture of a transformer that exhibits, when the steel sheet is applied to an iron core thereof, extremely low iron loss and extremely low noise properties, makes highly efficient use of energy, and can be used in various environments. The grain-oriented electrical steel sheet has a strain distribution in regions where closure domains are formed, when observed in a cross section in the rolling direction, with a maximum tensile strain in a sheet thickness direction being 0.45% or less, and with a maximum tensile strain t (%) and a maximum compressive strain c (%) in the rolling direction satisfying Expression (1):
t+0.06t+c0.35(1).

A method of controlling the cooling rate of a melt pool of a powder bed includes directing a first laser beam on the powder bed to form a melt pool; coaxially aligning a second laser beam with the first laser beam; and laterally offsetting a focus spot of the second laser beam with respect to the melt pool, wherein the second laser beam heats but does not melt powder within the focus spot.

Described herein are methods of constructing a three-dimensional part using metallic glass alloys, layer by layer, as well as metallic glass-forming materials designed for use therewith. In certain embodiments, a layer of metallic glass-forming powder or a sheet of metallic glass material is deposited to selected positions and then fused to a layer below by suitable methods such as laser heating or electron beam heating. The deposition and fusing are then repeated as need to construct the part, layer by layer. One or more sections or layers of non-metallic glass material can be included as needed to form composite parts. In one embodiment, the metallic glass-forming powder is a homogenous atomized powder. In another embodiment, the metallic glass-forming powder is formed by melting a metallic glass alloy to an over-heat threshold temperature substantially above the T.sub.liquidus of the alloy, and quenching the melt at a high cooling rate such that the cooling material is kept substantially amorphous during cooling to form the metallic glass. In various embodiments, the melt is atomized during cooling to form the metallic glass-forming powder.

Described herein are methods of constructing a three-dimensional part using metallic glass alloys, layer by layer, as well as metallic glass-forming materials designed for use therewith. In certain embodiments, a layer of metallic glass-forming powder or a sheet of metallic glass material is deposited to selected positions and then fused to a layer below by suitable methods such as laser heating or electron beam heating. The deposition and fusing are then repeated as need to construct the part, layer by layer. One or more sections or layers of non-metallic glass material can be included as needed to form composite parts. In one embodiment, the metallic glass-forming powder is a homogenous atomized powder. In another embodiment, the metallic glass-forming powder is formed by melting a metallic glass alloy to an over-heat threshold temperature substantially above the T.sub.liquidus of the alloy, and quenching the melt at a high cooling rate such that the cooling material is kept substantially amorphous during cooling to form the metallic glass. In various embodiments, the melt is atomized during cooling to form the metallic glass-forming powder.

The innovative wire annealing process is a constant process and includes wire heating by laser beams, and then wire reeling and cooling.