An induction heating device for heating a metal article includes a support plate with an upper surface for receiving the metal article, and a plurality of induction coils, which are arranged concentrically around an axis and are provided at an underside of the support plate. Each induction coil is connected to and selectively powered by a generator, and at least one temperature probe is disposeable on the metal article during heating in order to monitor and control the heating of the article.

A method of induction hardening a bearing ring includes positioning first and second inductors at a start zone on the bearing ring and a preheat inductor in an end zone on the bearing ring spaced one hundred eighty degrees from the start zone. A first traversing element moves the first inductor circumferentially from the start zone toward the end zone along a first half of the bearing ring circumference while the first inductor heats the bearing ring, and a second traversing element moves the second inductor circumferentially from the start zone toward the end zone along a second half of the bearing ring circumference while the second inductor heats the bearing ring. A third traversing element moves the preheat inductor circumferentially within the end zone so as to traverse a portion of each half of the bearing ring circumference while the preheat inductor heats the end zone.

A method of induction hardening a bearing ring includes positioning first and second inductors at a start zone on the bearing ring and a preheat inductor in an end zone on the bearing ring spaced one hundred eighty degrees from the start zone. A first traversing element moves the first inductor circumferentially from the start zone toward the end zone along a first half of the bearing ring circumference while the first inductor heats the bearing ring, and a second traversing element moves the second inductor circumferentially from the start zone toward the end zone along a second half of the bearing ring circumference while the second inductor heats the bearing ring. A third traversing element moves the preheat inductor circumferentially within the end zone so as to traverse a portion of each half of the bearing ring circumference while the preheat inductor heats the end zone.

The present application relates to the field of superalloy, disclosing a method for internal stress regulation in superalloy disk forgings by pre-spinning. The method includes: Step S1, determining a target revolution for regulating internal stress in the disk forgings, and determining a target deformation magnitude of plastic deformation required for regulating the internal stress by the pre-spinning of the disk forgings; and Step S2, performing the pre-spinning of the disk forgings by the target revolution, monitoring a deformation magnitude of the disk forgings, and stopping the pre-spinning when a monitored deformation magnitude of the disk forgings reaches the target deformation magnitude.

The present application relates to the field of superalloy, disclosing a method for internal stress regulation in superalloy disk forgings by pre-spinning. The method includes: Step S1, determining a target revolution for regulating internal stress in the disk forgings, and determining a target deformation magnitude of plastic deformation required for regulating the internal stress by the pre-spinning of the disk forgings; and Step S2, performing the pre-spinning of the disk forgings by the target revolution, monitoring a deformation magnitude of the disk forgings, and stopping the pre-spinning when a monitored deformation magnitude of the disk forgings reaches the target deformation magnitude.

An induction hardening system for inductively hardening a component includes a first inductor group with at least two inductors configured to heat a region to be hardened on the component, a drive unit configured to move the component along the at least two inductors, and a generator. The at least two inductors are electrically energized by the generator, and the generator is configured to send a current of a same frequency and a same strength to the at least two inductors of the first inductor group.

An induction hardening system for inductively hardening a component includes a first inductor group with at least two inductors configured to heat a region to be hardened on the component, a drive unit configured to move the component along the at least two inductors, and a generator. The at least two inductors are electrically energized by the generator, and the generator is configured to send a current of a same frequency and a same strength to the at least two inductors of the first inductor group.

A method for increasing load capacity of a surface-hardened rolling bearing raceway of a rolling bearing ring element may involve providing a rolling bearing ring element with an unhardened core region and, at least in certain portions, an outer layer hardened to a surface hardening depth. A rolling bearing raceway may be formed in a region of the hardened outer layer. The method may further involve hard rolling the rolling bearing raceway with a roll. The diameter of the roll is 8 to 25 times the surface hardening depth. A surface pressure prevailing in a rolling contact between the roll and the rolling bearing raceway during the hard rolling is between 2000 MPa and 3300 MPa. The method further involves machining the rolling bearing raceway after the hard rolling.

A method for increasing load capacity of a surface-hardened rolling bearing raceway of a rolling bearing ring element may involve providing a rolling bearing ring element with an unhardened core region and, at least in certain portions, an outer layer hardened to a surface hardening depth. A rolling bearing raceway may be formed in a region of the hardened outer layer. The method may further involve hard rolling the rolling bearing raceway with a roll. The diameter of the roll is 8 to 25 times the surface hardening depth. A surface pressure prevailing in a rolling contact between the roll and the rolling bearing raceway during the hard rolling is between 2000 MPa and 3300 MPa. The method further involves machining the rolling bearing raceway after the hard rolling.

A rolling bearing is a tapered roller bearing, a cylindrical roller bearing, or a deep groove ball bearing including an inner ring, an outer ring, and a rolling element, each of the inner ring, the outer ring, and the rolling element being composed of a steel, the rolling bearing having a quench-hardened layer in at least one of an inner ring raceway surface of the inner ring, an outer ring raceway surface of the outer ring, and a rolling contact surface of the rolling element. A ratio of a total area of a plurality of martensite crystal grains in the quench-hardened layer is more than or equal to 70%. The plurality of martensite crystal grains are classified into a first group and a second group. An average grain size of the martensite crystal grains belonging to the first group is less than or equal to 0.97 μm.