A method of grind hardening a workpiece is provided. The method may include securing the workpiece in a workpiece retainer and a grind tool in a tool retainer, rotating the grind tool in a first angular direction at a first angular speed, controlling the workpiece and tool retainers such that the grind tool engages the workpiece, and controlling the workpiece and tool retainers such that the grind tool is guided along a grinding track of the workpiece. The grind tool may engage and/or disengage the workpiece at portions of sacrificial material disposed thereon. Coolant and cleaning nozzles may be provided and controlled such that at least a portion of the coolant from the coolant nozzle is diverted to the cleaning nozzle in a manner which reduces heat dissipation, improves thermal efficiency of the grind hardening and reduces loading of the grind tool.

A method of grind hardening a workpiece is provided. The method may include securing the workpiece in a workpiece retainer and a grind tool in a tool retainer, rotating the grind tool in a first angular direction at a first angular speed, controlling the workpiece and tool retainers such that the grind tool engages the workpiece, and controlling the workpiece and tool retainers such that the grind tool is guided along a grinding track of the workpiece. The grind tool may engage and/or disengage the workpiece at portions of sacrificial material disposed thereon. Coolant and cleaning nozzles may be provided and controlled such that at least a portion of the coolant from the coolant nozzle is diverted to the cleaning nozzle in a manner which reduces heat dissipation, improves thermal efficiency of the grind hardening and reduces loading of the grind tool.

A steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.

A steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.

A metal material other than strain-free iron powder can be used as a reference piece for X-ray measurement of residual stress. The metal material is manufactured by nanocrystallizing at least a portion of a surface of a metal material, and then removing inherent strain by annealing the metal material, thereby eliminating stress.

A metal material other than strain-free iron powder can be used as a reference piece for X-ray measurement of residual stress. The metal material is manufactured by nanocrystallizing at least a portion of a surface of a metal material, and then removing inherent strain by annealing the metal material, thereby eliminating stress.

A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 m.

A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 m.

A steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.

A steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.