Method for producing turbine rotor and method for producing turbine

Patent metadata

Field	Value
Publication number	US-10752970-B2
Application number	US-201515737688-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 28, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

A method for producing a turbine rotor includes forming a rotor base material having a maximum outer diameter of 1000 mm or less from low-alloy steel including carbon, silicon, manganese, nickel, chromium, molybdenum, and vanadium; heating the rotor base material, by a quenching process, to a temperature range of 940° C. to 960° C.; performing oil quenching on the rotor base material, after the quenching process, in a temperature range of 250° C. to 500° C., at a cooling rate of at least 2.0° C./min; and tempering the rotor base material, after the quenching process, at a temperature of at least 630° C., and under a condition that a tempering parameter P is in the range of 19700 to 19900, wherein P is defined by the formula P=T (C+log(t)).

First claim

The invention claimed is:

1. A method for producing a turbine rotor, comprising:
forming a rotor base of an outer diameter of 500 mm to 1000 mm and the rotor base being made of a rotor base material comprising low-alloy steel that contains, in weight %:
carbon of 0.20% to 0.35%,
silicon of up to 0.35%,
manganese of up to 1.00%,
nickel of 0.50% to 1.50%,
chromium of 2.00% to 2.50%,
molybdenum of 0.90% to 1.50%, and
vanadium of 0.20% to 0.30%;

heating the rotor base material, by a heating process before quenching, to a temperature range of 940° C. to 960° C.;
quenching the rotor base material, after the heating process, until a temperature drops below 200° C. at a cooling rate of at least 2.0° C./min; and
tempering the rotor base material, after the quenching, at a temperature range of 655° C. to 665° C., and under a condition that a tempering parameter P is in a range of 19700 to 19900, wherein P is defined by a Formula P=T (C+log(t)), where T is an absolute temperature measured in Kelvin, t is time measured in hours and t is set to 10, and C is a material constant, and C is set to 20.

2. A method for producing a turbine, comprising:
fixing a plurality of blade rows to a turbine rotor such that the plurality of blade rows is arranged in a direction of a rotation axis of the turbine rotor obtained by the method for producing the turbine rotor according to claim 1 ;
providing a casing that covers the turbine rotor such that the turbine rotor and the blade rows are rotatable relative to each other about the rotation axis; and
fixing a plurality of vane rows to the casing such that each of the plurality of vane rows is disposed alternately with the blade rows in the direction of the rotation axis.

Assignees

• Mitsubishi Heavy Ind Compressor Corp
• Japan Casting Forging Corp

Inventors

• Terada Katsumi
• Miyata Takayuki
• Higuchi Takafumi
• Shibahara Hiroki

Classifications

• F01D5/02

  Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) · CPC title

• F05D2230/40

  Heat treatment · CPC title

• F01D5/286

  Particular treatment of blades, e.g. to increase durability or resistance against corrosion or erosion (F01D5/288 takes precedence) · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C21D1/58

  Oils · CPC title