Abstract: The present invention provides a high quality material for ring rolling. The material includes radially outer and inner peripheral surfaces. In the material, a center of gravity on a half section is located so as to be closer to the outer peripheral surface in contact with a main roll than a center of the half section in a thickness direction, a shape of the half section includes a height reducing portion having a height from a center line dividing the half section into halves in a height direction, this height is gradually reduced toward the inner peripheral surface in contact with a mandrel roll, and the shape is formed in a substantially linear symmetry such that the center line is a symmetric axis. A height of the inner peripheral surface is from 20% to 50% of a maximum height of the material.

Abstract: A manufacturing method provides a high-quality material for ring rolling. The manufacturing method of the material for ring rolling includes a step of heating a disk-shaped material for hot forging to a hot working temperature, a step of arranging the material for hot forging onto a lower die having a convex portion with a truncated conical shape, a step of forming a thin portion by pressing a center portion of the material for hot forging by using an upper die having a convex portion with a truncated conical shape, and a step of manufacturing a material for ring rolling by removing the thin portion wherein a center of gravity on a half section of the material for ring rolling is located so as to be closer to an outer peripheral surface of the half section than a center of the half section in a thickness direction of the half section.

Abstract: In a display system in an excavator, a position of an upper boundary line and a position of a lower boundary line are calculated. The upper boundary line indicates a height of a top of a cross section of a display object surface. The lower boundary line indicates a height of a bottom of the cross section of the display object surface. When the current position of the excavator is between the upper boundary line and the lower boundary line, a predetermined reference point of a display range is set to a predetermined position between the upper and lower boundary lines. When the current position of the excavator is above the upper boundary line, the reference point is set above the predetermined position. When the current position of the excavator is below the lower boundary line, the reference point is set below the predetermined position.

Abstract: An display system of an excavating machine includes: a vehicle condition detector detecting information related to a current position and a posture of the excavating machine having a work equipment including a bucket; a memory unit storing position information of a target surface indicating a target shape of an object to be worked; a display unit displaying the bucket and position information of a design surface and the target surface; and a processing unit calculating a position of a blade edge of the bucket based on the information related to the current position and the posture of the excavating machine, and, when at least part of the bucket enters a predetermined range in a periphery of the target surface in a direction orthogonal to the target surface, displaying a trajectory of the blade edge which is calculated based on the position of the blade edge and which exists in the predetermined range.

Abstract: A display system in a hydraulic shovel has a calculation unit and a display unit. The calculation unit is configured to calculate a distance between a design surface and a position closest to the design surface among positions of a blade edge of a bucket in a widthwise direction of the blade edge based on positional information for the blade edge and the design surface. The display unit is configured and arranged to display a guidance picture. The guidance picture includes an image showing the positional relationship between the design surface and the blade edge of the bucket, and information indicating the distance between the design surface and the position closest to the design surface.

Abstract: The display system of the excavating machine has a work machine condition detection unit which detects information related to a current position of an excavating machine and a processing unit. This processing unit calculates an icon display of the bucket and the positions of the excavation edge portions viewed from a top of the excavating machine based on the information related to the current position of the excavating machine, the information related to the posture of the main body, the information about the positions of the excavation edge portions and the outer shape information about the bucket, and displays on a screen of a display device the target surface, the icon display position of the bucket, and an image which indicates the positions of the excavation edge portions.

Abstract: A calculation unit of a hydraulic shovel display system sets a predetermined display range displayed as a guidance picture for land shape data. The guidance picture shows a cross section of a target surface included in a display range as seen from a side of a main vehicle body, and a current position of the hydraulic shovel. The calculation unit calculates a position of a start point nearest the main vehicle body and a position of an end point set apart from the start point by a maximum reach length of the work machine in the cross section of the target surface as seen from the side based on land shape data, work machine data and a current position of the main vehicle body. The calculation unit calculates a predetermined reference point of the display range based on the positions of the start point and the end point.

Abstract: The display system of the excavating machine has a work machine condition detection unit which detects information related to a current position of an excavating machine and a processing unit. This processing unit calculates an icon display of the bucket and the positions of the excavation edge portions viewed from a top of the excavating machine based on the information related to the current position of the excavating machine, the information related to the posture of the main body, the information about the positions of the excavation edge portions and the outer shape information about the bucket, and displays on a screen of a display device the target surface, the icon display position of the bucket, and an image which indicates the positions of the excavation edge portions.

Abstract: An display system of an excavating machine includes: a vehicle condition detector detecting information related to a current position and a posture of the excavating machine having a work equipment including a bucket; a memory unit storing position information of a target surface indicating a target shape of an object to be worked; a display unit displaying the bucket and position information of a design surface and the target surface; and a processing unit calculating a position of a blade edge of the bucket based on the information related to the current position and the posture of the excavating machine, and, when at least part of the bucket enters a predetermined range in a periphery of the target surface in a direction orthogonal to the target surface, displaying a trajectory of the blade edge which is calculated based on the position of the blade edge and which exists in the predetermined range.

Abstract: Provided is a method for fabricating a stepped forged material that can realize a uniform microscopic structure in both the large diameter flange portion and the small diameter shaft portion. This method for fabricating a stepped forged material comprises the following steps: a step for obtaining a primary forged material in which an austenite stainless steel billet is heated to 1000-1080° C., and, without any further heating, the material is forged by means of reciprocal forging into a round rod having along the entire length thereof a forging ratio of 1.5 or greater; a step for obtaining a secondary forged material, that forms the large diameter flange portion and the small diameter shaft portion, in which without reheating, the small diameter shaft portion is formed by means of reciprocal forging at a temperature where the surface temperature of the primary forged material never falls more than 200° C.

Abstract: In a hydraulic shovel positional guidance system, an optimal work position calculation unit is configured to calculate an optimal work position of a main vehicle body where a diggable range in which a target surface and an operability range overlap is largest. A display unit is configured to display a guidance picture showing the optimal work position.

Abstract: A display system in a hydraulic shovel has a calculation unit and a display unit. The calculation unit is configured to calculate a distance between a design surface and a position closest to the design surface among positions of a blade edge of a bucket in a widthwise direction of the blade edge based on positional information for the blade edge and the design surface. The display unit is configured and arranged to display a guidance picture. The guidance picture includes an image showing the positional relationship between the design surface and the blade edge of the bucket, and information indicating the distance between the design surface and the position closest to the design surface.

Abstract: In a hydraulic shovel positional guidance system, an optimal work position calculation unit is configured to calculate an optimal work position of a main vehicle body where a diggable range in which a target surface and an operability range overlap is largest. A display unit is configured to display a guidance picture showing the optimal work position.

Abstract: In a display system in an excavator, a position of an upper boundary line and a position of a lower boundary line are calculated. The upper boundary line indicates a height of a top of a cross section of a display object surface. The lower boundary line indicates a height of a bottom of the cross section of the display object surface. When the current position of the excavator is between the upper boundary line and the lower boundary line, a predetermined reference point of a display range is set to a predetermined position between the upper and lower boundary lines. When the current position of the excavator is above the upper boundary line, the reference point is set above the predetermined position. When the current position of the excavator is below the lower boundary line, the reference point is set below the predetermined position.

Abstract: A calculation unit of a hydraulic shovel display system sets a predetermined display range displayed as a guidance picture for land shape data. The guidance picture shows a cross section of a target surface included in a display range as seen from a side of a main vehicle body, and a current position of the hydraulic shovel. The calculation unit calculates a position of a start point nearest the main vehicle body and a position of an end point set apart from the start point by a maximum reach length of the work machine in the cross section of the target surface as seen from the side based on land shape data, work machine data and a current position of the main vehicle body. The calculation unit calculates a predetermined reference point of the display range based on the positions of the start point and the end point.

Abstract: To provide a high-rigidity flat grinding device, a substrate flat grinding device has three fastening plate lifting-and-lowering mechanisms that have kinematic couplings and a cylinder rod that move the fastening plate upward or downward. Being a high-rigidity grinding device in which the load of the fastening plate 6 also is a load on the grindstone 14 that does the grinding, there is little deflection in the thickness distribution of the substrates that are obtained, even if they are semiconductor substrates having a large substrate diameter of 450 mm.

Abstract: A method for producing a steel ingot, which comprises an Mg oxide forming step of preparing a molten steel containing Mg in an amount sufficient for the molten steel to have an oxide composition having MgO as a primary component and a dissociation step of keeping the pressure of the atmosphere around the molten steel to be lower than that in the Mg oxide forming step, to thereby dissociate MgO to Mg and oxygen and reduce the content of Mg in the steel to 50% or less of that in the Mg oxide forming step through the diffusion thereof into a gas phase. A preferred method further involves a solidifying step.

Abstract: To provide a high-rigidity flat grinding device, a substrate flat grinding device has three fastening plate lifting-and-lowering mechanisms that have kinematic couplings and a cylinder rod that move the fastening plate upward or downward. Being a high-rigidity grinding device in which the load of the fastening plate 6 also is a load on the grindstone 14 that does the grinding, there is little deflection in the thickness distribution of the substrates that are obtained, even if they are semiconductor substrates having a large substrate diameter of 450 mm.

Abstract: Disclosed is a method of producing maraging steel, which includes producing a consumable electrode for vacuum remelting; and subjecting the consumable electrode to the vacuum remelting. The consumable electrode contains not less 5 ppm Mg. Disclosed is also a maraging steel containing, by mass %, at least, from more than zero to less than 10 ppm Mg, less than 10 ppm oxygen, and less than 15 ppm nitrogen. The steel contains also nitride inclusions having a maximum length of not more than 15 ?m and oxide inclusions having a maximum length of not more than 20 ?m. Regarding the oxide inclusions, a content rate of spinel form inclusions having a length of not less than 10 ?m to a total content of the spinel form inclusions having a length of not less than 10 ?m and alumina inclusions having a length of not less than 10 ?m exceeds 0.33 (i.e. 33%).

Abstract: A method for producing a steel ingot, which comprises an Mg oxide forming step of preparing a molten steel containing Mg in an amount sufficient for the molten steel to have an oxide composition having MgO as a primary component and a dissociation step of keeping the pressure of the atmosphere around the molten steel to be lower than that in said Mg oxide forming step, to thereby dissociate MgO to Mg and oxygen and reduce the content of Mg in the steel to 50% or less of that in the Mg oxide forming step through the diffusion thereof into a gas phase; and a preferred method further comprising a solidifying step, which comprises an Mg oxide forming step of preparing a first molten steel containing Mg in an amount sufficient for the molten steel to have an oxide composition having MgO as a primary component, a step of solidifying the molten steel, and a dissociation step of melting the resultant solid again under a pressure of an atmosphere lower than that in the case of the first molten steel, to thereby dissoc