The invention relates to a method for the inductive surface layer hardening of a surface which runs around an annular component and has an initial zone, an end zone and two intermediate zones extending between the initial zone and the end zone. The initial zone is brought to hardening temperature by an inductor and quenched by a spray. Subsequently, an inductor arrangement is moved in each case along the intermediate zone to the end zone. Each inductor arrangement includes a leading inductor for preheating the region covered by it, a trailing inductor for finish-heating the preheated region and a spray for quenching the finish-heated region. After the inductor arrangements are located at a certain distance from the initial zone, the leading inductor of at least one of the inductor arrangements is moved in the direction of the end zone at an increased feed rate compared to the trailing inductor. The leading inductor thus reaches the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to overcome the distance previously resulted between said trailing inductor and the leading inductor. In the meantime, the end zone is preheated by the leading inductor that reached it. When one of the trailing inductors of the inductor arrangements has arrived in the end zone, it heats the end zone to the finished hardening temperature.

A device for heating and quenching a tubular member has a central axis. The device includes a first quenching ring, a second quenching ring axially spaced from the first quenching ring, and a heating ring axially positioned between the first quenching ring and the second quenching ring. Each quenching ring and the heating ring is configured to receive the tubular member. The heating ring is fixably coupled to the first quenching ring and the second quenching ring. The heating ring includes an induction coil configured to heat an annular target zone along the tubular member. The first quenching ring is configured to deliver a first quenching fluid to the target zone and a first annular heat affected zone along the tubular member, and the second quenching ring is configured to deliver a second quenching fluid to the target zone and a second annular heat affected zone along the tubular member.

A device for heating and quenching a tubular member has a central axis. The device includes a first quenching ring, a second quenching ring axially spaced from the first quenching ring, and a heating ring axially positioned between the first quenching ring and the second quenching ring. Each quenching ring and the heating ring is configured to receive the tubular member. The heating ring is fixably coupled to the first quenching ring and the second quenching ring. The heating ring includes an induction coil configured to heat an annular target zone along the tubular member. The first quenching ring is configured to deliver a first quenching fluid to the target zone and a first annular heat affected zone along the tubular member, and the second quenching ring is configured to deliver a second quenching fluid to the target zone and a second annular heat affected zone along the tubular member.

A method for manufacturing a forged component includes: performing hot forging on a material; heating the hot forged material to a first set temperature; and performing warm coining to correctly shape the heated material. The material may be heated to a second set temperature before hot forging. The material heated to the second set temperature may be hot forged. The second set temperature may be higher than the first set temperature. The hot forged material may be subjected to controlled cooling to a third set temperature at a predetermined cooling rate. The controlled cooled material may be heated to the first set temperature. The third set temperature may be lower than or equal to the first set temperature.

A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.

A cold rolled steel flat product for packaging made of a low carbon steel having a thickness of less than 0.49 mm and a method of making. The steel flat product has a martensite-free microstructure and represents a standard grade for packaging with tensile strengths from 300 to 550 MPa, which can be produced from a cold-rolled steel sheet with a carbon content from 0.01% to 0.1% by weight by inductive annealing of the steel sheet and subsequent water cooling for quenching the recrystallization-annealed steel sheet. To achieve flatness of 5 I-units or less, the induction annealed steel sheet is first primarily cooled in the manufacturing process to a take-off temperature at a rate of less than 1000 K/s, with the take-off temperature being below the transformation temperature of 723° C., and thereafter a secondary cooling by water cooling with a water temperature of less than 80° C. at a rate of more than 1000 K/s.

A hot and cold composite formed square and rectangular steel tube and a production method for the same are provided. The radius of an outer corner of the square and rectangular steel tube meets the following conditions: when t is less than or equal to 6 mm, R is greater than 0 and less than 2.0 t; when t is greater than 6 mm and less than or equal to 10 mm, R is greater than 0 and less than 2.5 t; when t is greater than 10 mm, R is greater than 0 and less than 3.0 t, wherein t is the wall thickness of a straight tube part of the square and rectangular steel tube; R is the radius of each of the outer corners of the four corners of the square and rectangular steel tube; and the wall thickness of each corner of the square and rectangular steel tube is between 1.0 t and 1.8 t.

The invention provides a heat treatment method for a steel product. The steel product includes at least 0.5-0.7% of Si by weight; the method provides the following steps: step 1) putting the steel product under an Austenitizing temperature of 830-890° C. and lasting for a first time to Austenitize the steel product, step 2) immersing the Austenitized steel product in a salt bath at an isothermal temperature of 200-350° C. and lasting for the second time. The method of the invention improves the toughness and elongation of the steel product, keeps the wear resistance of the product, and can be well applied to the fields of thin section ring of bearings and the like. The invention also provides a steel product and a bearing ring.

An integrated welding and thermal processing method includes heating adjoining surfaces, at least one of which is a creep strength enhanced ferritic (CSEF) steel alloy, to a sufficiently high temperature above their melting points to form a weld. The weld is allowed cool below the martensitic start temperature of one or both CSEF alloys. Thereafter, a supplemental heat source tempers the CSEF alloys by reheating the weld area at a rate of 10° C. per second or greater to above the CSEF alloys’ martensitic start temperatures, but not above the austenitization temperature of the CSEF alloys. After the weld’s heat affected zone is maintained at a temperature between the CSEF alloys’ martensitic finish temperature and martensitic start temperature, the weld is allowed to cool at a rate of 15° C. per minute or greater.

An integrated welding and thermal processing method includes heating adjoining surfaces, at least one of which is a creep strength enhanced ferritic (CSEF) steel alloy, to a sufficiently high temperature above their melting points to form a weld. The weld is allowed cool below the martensitic start temperature of one or both CSEF alloys. Thereafter, a supplemental heat source tempers the CSEF alloys by reheating the weld area at a rate of 10° C. per second or greater to above the CSEF alloys’ martensitic start temperatures, but not above the austenitization temperature of the CSEF alloys. After the weld’s heat affected zone is maintained at a temperature between the CSEF alloys’ martensitic finish temperature and martensitic start temperature, the weld is allowed to cool at a rate of 15° C. per minute or greater.