Method of producing polygonal ring-shaped machine parts having complex cross-section

Abstract

Disclosed is a method of producing a polygonal, ring-shaped machine part having a complex cross-section starting from a metal rod with improved productivity and remarkably increased material yield. The method comprises the steps of: forging a rod to prepare a notched blank 1 having large diameter parts 11 and the remaining small diameter parts 12; bending the large diameter parts 11 to form a first intermediate 3 of polygonal, open ring-shape and a complex cross-section with confronting ends; butting and welding the confronting ends of the first intermediate 3 to form a second intermediate 5; die-forging the second intermediate 5 to form a ring-shaped product 7; and subjecting the product 7 to necessary finishing step such as machining to obtain the final product.

Description

[0001] 1. Field in the Industry[0002] The present invention concerns a method of producing a polygonal, particularly square, ring-shaped machine part having a complex cross-section from metallic material.[0003] 2. Prior Art[0004] To date, when it is intended to produce a machine part such as "frame" or a sealing ring for transition piece of a gas turbine combustor as shown in FIG. 1 (plan view) and FIG. 2 (side view), which has curved profile in one or both of plan view and side view (the illustrated example is curvilinear in the plan view) and a complex cross-section such as shown in FIG. 3 from metallic material, the only practical way to carry out the production is cutting a metal plate by water jet or fusion to prepare a blank and machining the blank. In case where the metallic material is an expensive alloy like a Ni-based super alloy having high heat resistance (e.g., Hastelloy X or Nimonic 263) or a Co-based super alloy (e.g., L605), the fact that there is no method of produc...

AI Technical Summary

Problems solved by technology

In case where the metallic material is an expensive alloy like a Ni-based super alloy having high heat resistance (e.g., Hastelloy X or Nimonic 263) or a Co-based super alloy (e.g., L605), the fact that there is no method of producing other than the above method of low material yield means very high production costs of the part.

From the viewpoint of product variation, if a part of complex cross-section is to be produced, the amount of material to be removed from the blank by machining is a significant matter and the processing is disadvantageous from both the material yield and time consumption.

However, use of a thicker blank necessitates cutting off of large amount of the material at the parts other than the parts to be bent, and gives adverse effect to the intension of the invention.

The same problem is experienced in the case of, for example, an angular ring-shaped machine part, if there is a large difference between the thickness of a pair of longer sides and that of a pair of shorter sides, then the rod blanks must be prepared by taking the thicker sides as the standard.

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