IP Library Granted Patent US 8,853,903
Granted Patent B2
US 8,853,903 · App. 12/559,628 · Granted Oct 7, 2014

Low alloy steel material for generator rotor shafts

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Quick Facts
Patent No.
US 8,853,903
App. No.
12/559,628
Granted
Oct 7, 2014
Kind
B2
Abstract

Disclosed is a low alloy steel material for generator rotor shafts, which has tensile strength of not less than 700 MPa at room temperature. Preferably the low alloy steel material consists of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.15 to 0.35% Cu, 0.06 to 0.14% V, and the balance of Fe and unavoidable impurities.

Claims (7)

1. A low alloy steel for generator rotor shafts, consisting essentially of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.20 to 0.30% Cu, 0.06 to 0.14% V, an absence of tungsten, and the balance of Fe and unavoidable impurities, wherein the low alloy steel has not higher than 275 AT/m of magnetizing force and wherein the low alloy steel has a FATT of not higher than 7° C.

2. The low alloy steel according to claim 1 , which has tensile strength of not less than 700 MPa at room temperature.

3. A generator having a rotor shaft made of the low alloy steel as defined in claim 1 .

4. A low alloy steel for generator rotor shafts, consisting essentially of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.5 to 1.8% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.15 to 0.35% Cu, 0.06 to 0.14% V. an absence of tungsten, and the balance of Fe and unavoidable impurities, wherein the low alloy steel has not higher than 275 AT/m of magnetizing force and wherein the low alloy steel has a FATT of not higher than 7° C.

5. The low alloy steel according to claim 4 which contains 2.30 to 2.80% Cr.

6. The low alloy steel according to claim 5 which contains 0.20 to 0.30% Cu.

7. The low alloy steel according to claim 5 which contains 0.30 to 0.40% Mo.

Assignments (7)
NUNC PRO TUNC ASSIGNMENT Recorded Nov 25, 2024
From: MITSUBISHI HEAVY INDUSTRIES, LTD.
To: MITSUBISHI GENERATOR CO., LTD.
Reel/Frame 069438/0941 →
NUNC PRO TUNC ASSIGNMENT Recorded Sep 11, 2023
From: MITSUBISHI POWER, LTD.
To: MITSUBISHI HEAVY INDUSTRIES, LTD.
Reel/Frame 064854/0880 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVING PATENT APPLICATION NUMBER 11921683 PREVIOUSLY RECORDED AT REEL: 054975 FRAME: 0438. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded May 26, 2023
From: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
To: MITSUBISHI POWER, LTD.
Reel/Frame 063787/0867 →
CHANGE OF NAME Recorded Jan 13, 2021
From: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
To: MITSUBISHI POWER, LTD.
Reel/Frame 054975/0438 →
CONFIRMATORY ASSIGNMENT Recorded Oct 8, 2014
From: HITACHI, LTD.
To: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
Reel/Frame 033917/0209 →
CHANGE OF NAME Recorded May 11, 2014
From: HITACHI, LTD.
To: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
Reel/Frame 032865/0800 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 15, 2009
From: MORI, TAKANOBU
To: HITACHI, LTD.
Reel/Frame 023230/0367 →