Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Director-general of the Agency of Industrial Science and Technology

Seiya Furuta

Kenji Iwai

Masahiro Chiji

Kenichi Aota

Kohro Takatsuka

Shigeki Saka

Nobuyasu Kawai

Hiroshi Takigawa

Masaru Saito

Kazuo Ogata

The invention provides a method for making a novel porous sintered material according to an HIP (Hot Isostatic Press) molding technique usually used for the purpose of obtaining defect-free and highly dense powder products. In the method of the invention, a capsule containing a starting powder in a hermetically sealed condition is heated according to a predetermined temperature pattern and is also subjected to hot isostatic pressing while a pressure is arrived at a maximum pressure level substantially in coincidence with commencement of a sintering temperature-applying period in the temperature pattern and is gradually lowered from the maximum pressure level during the sintering temperature-applying period. By the method, excessive densification is suppressed and the resulting sintered material has a required porosity and is provided with pores open to outside in the inside thereof, along with good strength and surface processability.

Method for making a porous sintered material

The method concerns fabricating heat-resistant heavy-duty components of a rbine, e.g. disk, wheel, etc. wherein two or more different kinds of alloys are junctioned, which comprises solidifying the one alloy powder by hot isostatic pressing or extrusion, junctioning and solidifying the solidified alloy with the other alloy powder by hot isostatic pressing or extrusion, and subjecting the alloys thus obtained to superplasticity forging thereby to secure the junction boundary. Ni-base superalloys having different complete solid solution temperatures of gamma prime phase are selected for use in the hub and rim of a turbine disk or the like, the one alloy which is higher in the temperature being disposed for the hub and the other alloy for the rim. The difference in the temperature between both alloys is at least 8.degree. C. Further solution heat treatment is performed at a temperature between the complete solid solution temperatures to adjust crystal grain size. Heat-resistant heavy-duty components of a turbine, e.g. disk, etc. are thus fabricated by superplasticity forging from Ni-base superalloys.

Method of making heat resistant heavy-duty components of a turbine by

A process is provided for heating steel powder compacts in a controlled atmosphere consisting of a primary gas containing at least 80% by volume of an inert gas, and a secondary gas comprising 0.1 to 5% by volume, based on the volume of said primary gas, of a paraffinic hydrocarbon. The process makes it possible to reduce the residual oxygen concentration in the steel powder compacts, while maintaining accurate control of the carbon content.

Process for heating steel powder compacts

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Kobe, Japan

Seiya Furuta