Case-hardenable stainless steel alloy

Patent metadata

Field	Value
Publication number	US-2018073113-A1
Application number	US-201715695648-A
Country	US
Kind code	A1
Filing date	Sep 5, 2017
Priority date	Sep 13, 2016
Publication date	Mar 15, 2018
Grant date	—

Abstract

A steel alloy for a bearing, the alloy having a composition having from 0.04 to 0.1 wt. % carbon, from 10.5 to 13 wt. % chromium, from 1.5 to 3.75 wt. % molybdenum, from 0.3 to 1.2 wt. % vanadium, from 0.3 to 2.0 wt .% nickel, from 6 to 9 wt. % cobalt, from 0.05 to 0.4 wt. % silicon, from 0.2 to 0.8 wt. % manganese, from 0.02 to 0.06 wt. % niobium, from 0 to 2.5 wt. % copper, from 0 to 0.1 wt. % aluminium, from 0 to 250 ppm nitrogen, from 0 to 30 ppm boron, and the balance iron, together with any unavoidable impurities.

First claim

1 . A steel alloy for a bearing, the alloy having a composition comprising:
from 0.04 to 0.1 wt. % carbon, from 10.5 to 13 wt. % chromium, from 1.5 to 3.75 wt. % molybdenum, from 0.3 to 1.2 wt. % vanadium, from 0.3 to 2.0 wt. % nickel from 6 to 9 wt. % cobalt, from 0.05 to 0.4 wt. % silicon, from 0.2 to 0.8 wt. % manganese, from 0.02 to 0.06 wt. % niobium, from 0 to 2.5 wt. % copper, from 0 to 0.1 wt. % aluminium, from 0 to 250 ppm nitrogen, from 0 to 30 ppm boron, and the balance iron, together with any unavoidable impurities.

2 . The steel alloy of claim 1 , comprising from 0.05 to 0.09 wt. % carbon.

3 . The steel alloy of claim 1 , comprising from 10.7 to 12.7 wt. % chromium, more preferably from 11 to 12.5 wt. % chromium.

4 . The steel alloy of claim 1 , comprising from 1.65 to 3.6 wt. % molybdenum.

5 . The steel alloy of claim 1 , comprising from 0.4 to 1.1 wt. % vanadium.

6 . The steel alloy of claim 1 , comprising at least 0.65 wt. % vanadium.

7 . The steel alloy of claim 1 , comprising from 0.3 to 1.9 wt. % nickel.

8 . The steel alloy of claim 1 , comprising from 6.5 to 7.7 wt. % cobalt.

9 . The steel alloy of claim 1 , comprising from 0.05 to 0.3 wt. % silicon.

10 . The steel alloy of claim 1 , comprising from 0.3 to 0.7 wt. % manganese.

11 . The steel alloy of claim 1 , comprising from 0.02 to 0.04 wt. % niobium.

12 . A bearing component made from the steel alloy of claim 1 , wherein a surface of the bearing component is case-carburised and/or carbonitrided.

13 . A bearing comprising a bearing component according to claim 12 , the bearing component being formed by at least one of an inner ring, an outer ring, or a rolling element of the bearing.

14 . The bearing of claim 13 , wherein the bearing component is an inner ring and an outer ring, and the bearing further comprises rolling elements made of a ceramic material.

15 . The steel alloy of claim 2 , comprising from 0.06 to 0.08 wt. % carbon.

16 . The steel alloy of claim 15 , comprising 0.07 wt. % carbon.

17 . The steel alloy of claim 3 , comprising from 11 to 12.5 wt. % chromium.

18 . The steel alloy of claim 5 , comprising from 0.5 to 1.1 wt. % vanadium.

Assignees

• Skf Ab
• Skf Aerospace France Sas

Inventors

• Sherif Mohamed
• Beswick John
• Larsson Staffan
• Maheo Yves

Classifications

• F16C33/303

  of hybrid bearings, e.g. rolling bearings with steel races and ceramic rolling elements · CPC title

• F16C2223/16

  with carbo-nitriding · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C38/48

  with niobium or tantalum · CPC title

• C22C38/52 Primary

  with cobalt · CPC title