A metal surface treatment method wherein the surface (10) is simultaneously bombarded with a mixture of abrasive particles (4) and dopant particles (6) which are delivered at a velocity in the range of 50-250 m/sec, and thereby depositing the dopant material on the surface. Also provided is an article (8) having a surface treated by such a method.

A blasting abrasive includes a particle of hot melt resin and abrasive grains to be firmly fixed to the particle, a blasting method further includes preparing a blasting abrasive including particles of hot melt resin and abrasive grains to be firmly fixed to the particles, heating gas, and injecting both the blasting abrasive and the heated gas.

A blasting abrasive includes a particle of hot melt resin and abrasive grains to be firmly fixed to the particle, a blasting method further includes preparing a blasting abrasive including particles of hot melt resin and abrasive grains to be firmly fixed to the particles, heating gas, and injecting both the blasting abrasive and the heated gas.

A method of treating a surface of a mold. A preliminary treatment of dry-ejecting an angular carbide powder against the surface of the mold so as to cause elemental carbon present within the carbide powder to be diffused into the surface of the mold. The carbide powder has particle diameters not larger than those of a 220 grit and the carbide powder being dry-ejected at an ejection pressure of 0.2 MPa or greater. An after-treatment of dry-ejecting a spherical powder against the surface of the mold to cause the spherical powder to impact the surface of the mold and form innumerable circular arc shaped fine depressions. The spherical powder has a hardness not less than the hardness of a base material of metal of the mold and particle diameters not larger than those of a 220 grit and dry-ejected at an ejection pressure of 0.2 MPa or greater.

A method of treating a surface of a mold. A preliminary treatment of dry-ejecting an angular carbide powder against the surface of the mold so as to cause elemental carbon present within the carbide powder to be diffused into the surface of the mold. The carbide powder has particle diameters not larger than those of a 220 grit and the carbide powder being dry-ejected at an ejection pressure of 0.2 MPa or greater. An after-treatment of dry-ejecting a spherical powder against the surface of the mold to cause the spherical powder to impact the surface of the mold and form innumerable circular arc shaped fine depressions. The spherical powder has a hardness not less than the hardness of a base material of metal of the mold and particle diameters not larger than those of a 220 grit and dry-ejected at an ejection pressure of 0.2 MPa or greater.

A method for manufacturing a magnetostrictive torque sensor shaft (100) to which a sensor portion (2) of a magnetostrictive torque sensor (1) is to be attached includes: a heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process; a shot peening step of performing shot peening using a steel shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion (2) is to be attached; and a surface polishing step of subjecting the shaft member after the shot peening to surface polishing.

A method for manufacturing a magnetostrictive torque sensor shaft (100) to which a sensor portion (2) of a magnetostrictive torque sensor (1) is to be attached includes: a heat treatment step of subjecting an iron-based shaft member to a carburizing, quenching, and tempering process; a shot peening step of performing shot peening using a steel shot media having a Vickers hardness at least equal to 1100 and at most equal to 1300, at least in a position on the shaft member, after the heat treatment step, to which the sensor portion (2) is to be attached; and a surface polishing step of subjecting the shaft member after the shot peening to surface polishing.

Provided is a wet blasting treatment device including a first nozzle unit that discharges, toward a target treatment region of a workpiece, slurry in which a first liquid and abrasive grains are mixed, a second nozzle unit that discharges a second liquid toward an untreated region adjacent to the target treatment region such that a liquid film is formed in the target treatment region of the workpiece, and a control unit that controls a discharge amount of the second liquid discharged by the second nozzle unit such that the liquid film has a predetermined thickness.

A blasting abrasive and a method of use are provided. The blasting abrasive includes a ferrochrome slag having a composition of SiO.sub.2 in a range of from about 30 to 40 wt% (weight percent); Al.sub.2O.sub.3 in a range of from about 25 to 35 wt%; of Fe.sub.2O.sub.3, Cr.sub.2O.sub.3, or a combination thereof in a range of from about 10-20 wt%; MgO in a range of from about 15 to 25 wt%, by weight of the ferrochrome slag. The ferrochrome slag has a particle size in a range of from about 100 to 850 .Math.m (micrometers) with a particular size distribution.

A blasting abrasive and a method of use are provided. The blasting abrasive includes a ferrochrome slag having a composition of SiO.sub.2 in a range of from about 30 to 40 wt% (weight percent); Al.sub.2O.sub.3 in a range of from about 25 to 35 wt%; of Fe.sub.2O.sub.3, Cr.sub.2O.sub.3, or a combination thereof in a range of from about 10-20 wt%; MgO in a range of from about 15 to 25 wt%, by weight of the ferrochrome slag. The ferrochrome slag has a particle size in a range of from about 100 to 850 .Math.m (micrometers) with a particular size distribution.