A method for peening an obstructed region of a metal assembly that is obstructed by an obstructing part of the metal assembly is provided. The method includes determining an optimal peening path for treating the obstructed region irrespective of the obstructing part; identifying a portion of the obstructing part within the optimal peening path; determining a section of the portion of the obstructing part that is removable without affecting a mechanical integrity and functionality of the obstructing part; removing, by machining, the section so as to create additional space along the optimal peening path; and peening the obstructed region, a path of the peening at least partially crossing through the additional space. A method for peening a nuclear reactor pressure vessel is also provided.

The invention relates to sheet metal packaging products, in particular tinplate or electrolytically chrome-plated sheet steel (ECCS), consisting of a sheet steel substrate (S) with a thickness in the region of 0.1 mm to 0.6 mm and a coating (B), in particular made of tin and/or chromium or chromium and chromium oxide, that is electrolytically deposited on at least one side of the sheet metal substrate. In addition, at least one surface of the sheet metal packaging product provided with the coating (B) has a surface profile with periodically repeating structure elements in at least one direction, wherein an autocorrelation function resulting from the surface profile has a plurality of side lobes with a height of at least 20%, preferably at least 30% of the height of the main lobe. These sheet metal packaging products have improved and novel surface properties.

The invention relates to sheet metal packaging products, in particular tinplate or electrolytically chrome-plated sheet steel (ECCS), consisting of a sheet steel substrate (S) with a thickness in the region of 0.1 mm to 0.6 mm and a coating (B), in particular made of tin and/or chromium or chromium and chromium oxide, that is electrolytically deposited on at least one side of the sheet metal substrate. In addition, at least one surface of the sheet metal packaging product provided with the coating (B) has a surface profile with periodically repeating structure elements in at least one direction, wherein an autocorrelation function resulting from the surface profile has a plurality of side lobes with a height of at least 20%, preferably at least 30% of the height of the main lobe. These sheet metal packaging products have improved and novel surface properties.

Laser shock peening is applied to a harvester component for an agricultural wear application that for example may be any of the following components: a knifeback, a knifehead, a knifeback connecting strap, a straw chopper, a sickle section, stalk chopper, a bedknife, a sod cutter knife, a net wrap knife or a combine concave component. The laser shock peening may be selectively applied. For example, laser shock peening can be applied in regions of drive ends of harvester components, and/or in regions proximate fastener holes of such harvester components.

A method of preparing an engine valve is provided. The method includes hot forging a heat resistant steel at 1,150 to 1,250° C. to mold a valve, aging the molded valve and hollowed-out processing the aging valve. Additionally, the method includes nitride-heating the hollow valve and grinding a surface of a neck of the nitride-heated valve to remove a nitride layer.

A method of preparing an engine valve is provided. The method includes hot forging a heat resistant steel at 1,150 to 1,250° C. to mold a valve, aging the molded valve and hollowed-out processing the aging valve. Additionally, the method includes nitride-heating the hollow valve and grinding a surface of a neck of the nitride-heated valve to remove a nitride layer.

A method for relieving residual stresses in a part includes increasing the rotation speed, which includes measuring, at a first given instant, values representative of the rotation speed and the radial enlargement; measuring, at a second given instant after the first instant, values representative of the rotation speed and the radial enlargement; determining a leading coefficient of a first affine function from the preceding values; determining a target radial enlargement value as a function of a value representative of the rotation speed, in the form of a second affine function, the origin of which is the value of a desired final residual enlargement and the leading coefficient of which is the leading coefficient of the first affine function; stopping the increase in rotation speed of the part from the moment that the actual enlargement of the rotating part corresponds to the target relative radial enlargement value that has been determined.

A method for relieving residual stresses in a part includes increasing the rotation speed, which includes measuring, at a first given instant, values representative of the rotation speed and the radial enlargement; measuring, at a second given instant after the first instant, values representative of the rotation speed and the radial enlargement; determining a leading coefficient of a first affine function from the preceding values; determining a target radial enlargement value as a function of a value representative of the rotation speed, in the form of a second affine function, the origin of which is the value of a desired final residual enlargement and the leading coefficient of which is the leading coefficient of the first affine function; stopping the increase in rotation speed of the part from the moment that the actual enlargement of the rotating part corresponds to the target relative radial enlargement value that has been determined.

A method for manufacturing a part of nitrided steel includes a step of nitriding the part. After nitriding, laser shocking is carried out on a surface of the nitrided part.

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves and includes two or more broken lines including the grooves having a length of 5 to 10 mm on a straight line intersecting a rolling direction on the steel sheet surface. In each of the broken lines including the grooves, the grooves are arranged at equal intervals, and a ratio of the length of the groove to a length of a non-groove is in a range of 1:1 to 1.5:1.