Grain-oriented electrical steel sheets with good magnetic properties are industrially stably produced, by using as the material, a steel slab having a predetermined composition, wherein after cold rolling and before the start of secondary recrystallization annealing, the cold rolled sheet is subjected to nitriding treatment with nitrogen content of 50 mass ppm or more and 1000 mass ppm or less, and a total content of 0.2 mass % to 15 mass % of a sulfide and/or sulfate is contained in an annealing separator, and a staying time in the temperature range of 300 C. to 800 C. in the heating stage of secondary recrystallization annealing of 5 hours or more is secured to precipitate silicon nitride (Si.sub.3N.sub.4) and MnS, and using the silicon nitride in combination with MnS as inhibiting force for normal grain growth to significantly reduce variation of magnetic properties.

This invention relates to a partially carbonitriding heat treated stainless steel ferrule, having a first region with a first hardness and a second region with a second hardness, wherein the first region includes a nitrogen layer having a nitrogen concentration higher than a carbon concentration, and a carbon layer formed under the nitrogen layer and having a carbon concentration higher than a nitrogen concentration, so that the first hardness is greater than the second hardness. Thereby, partial heat treatment is effective at preventing rotational torque of the region, except for the portion to be heat treated, from increasing due to the total hardening.

This invention relates to a partially carbonitriding heat treated stainless steel ferrule, having a first region with a first hardness and a second region with a second hardness, wherein the first region includes a nitrogen layer having a nitrogen concentration higher than a carbon concentration, and a carbon layer formed under the nitrogen layer and having a carbon concentration higher than a nitrogen concentration, so that the first hardness is greater than the second hardness. Thereby, partial heat treatment is effective at preventing rotational torque of the region, except for the portion to be heat treated, from increasing due to the total hardening.

A magnetic component having intermixed first and second regions, and a method of preparing that magnetic component are disclosed. The first region includes a magnetic phase and the second region includes a non-magnetic phase. The method includes mechanically masking pre-selected sections of a surface portion of the component by using a nitrogen stop-off material and heat-treating the component in a nitrogen-rich atmosphere at a temperature greater than about 900 C. Both the first and second regions are substantially free of carbon, or contain only limited amounts of carbon; and the second region includes greater than about 0.1 weight % of nitrogen.

A magnetic component having intermixed first and second regions, and a method of preparing that magnetic component are disclosed. The first region includes a magnetic phase and the second region includes a non-magnetic phase. The method includes mechanically masking pre-selected sections of a surface portion of the component by using a nitrogen stop-off material and heat-treating the component in a nitrogen-rich atmosphere at a temperature greater than about 900 C. Both the first and second regions are substantially free of carbon, or contain only limited amounts of carbon; and the second region includes greater than about 0.1 weight % of nitrogen.

Presented is a method, apparatus, and computer-readable medium for carburization. A method includes creating a vacuum within an interior of a chamber, the interior of the chamber including an item, the item having a first portion and a second portion, and providing an inert gas and a carbon product to the interior of the chamber. The method further including heating by induction the first portion of the item to induce carburization of the first portion of the item, and in response to the heating, cooling a second portion of the item such that the second portion of the item maintains its structural integrity.

Presented is a method, apparatus, and computer-readable medium for carburization. A method includes creating a vacuum within an interior of a chamber, the interior of the chamber including an item, the item having a first portion and a second portion, and providing an inert gas and a carbon product to the interior of the chamber. The method further including heating by induction the first portion of the item to induce carburization of the first portion of the item, and in response to the heating, cooling a second portion of the item such that the second portion of the item maintains its structural integrity.

A method for selective carburization of an article using low pressure induction carburization includes: providing or procuring an article including a surface; subjecting the article to directed induction heating, wherein a first portion of the surface of the article is inductively heated to a temperature that exceeds a carburizing temperature, while a second portion of the surface of the article remains at a temperature below the carburizing temperature; and simultaneously with subjecting the article to directed induction heating, subjecting the article to low pressure carburization, thereby selectively carburizing the first portion of the surface of the article while not carburizing the second portion of the surface of the article.

A method for selective carburization of an article using low pressure induction carburization includes: providing or procuring an article including a surface; subjecting the article to directed induction heating, wherein a first portion of the surface of the article is inductively heated to a temperature that exceeds a carburizing temperature, while a second portion of the surface of the article remains at a temperature below the carburizing temperature; and simultaneously with subjecting the article to directed induction heating, subjecting the article to low pressure carburization, thereby selectively carburizing the first portion of the surface of the article while not carburizing the second portion of the surface of the article.

A magnetic component having intermixed first and second regions, and a method of preparing that magnetic component are disclosed. The first region includes a magnetic phase and the second region includes a non-magnetic phase. The method includes mechanically masking pre-selected sections of a surface portion of the component by using a nitrogen stop-off material and heat-treating the component in a nitrogen-rich atmosphere at a temperature greater than about 900 C. Both the first and second regions are substantially free of carbon, or contain only limited amounts of carbon; and the second region includes greater than about 0.1 weight % of nitrogen.