Method for producing a low-alloy steel ingot

Patent metadata

Field	Value
Publication number	US-2017130297-A1
Application number	US-201515317508-A
Country	US
Kind code	A1
Filing date	Jun 3, 2015
Priority date	Jun 10, 2014
Publication date	May 11, 2017
Grant date	—

Abstract

A method of fabricating a low alloy steel ingot, the method including a) melting all or part of an electrode by a vacuum arc remelting method, the electrode, before melting, including iron and carbon, the melted portion of the electrode being collected in a crucible, thus forming a melt pool within the crucible; and b) solidifying the melt pool by heat exchange between the melt pool and a cooling fluid, the heat exchange applied serving to impose a mean solidification speed during step b) that is less than or equal to 45 μm/s and to obtain an ingot of low alloy steel.

First claim

1 . A method of fabricating a low alloy steel ingot, the method comprising:
a) melting all or part of an electrode by a vacuum arc remelting method, the electrode, before melting, comprising iron and carbon, the melted portion of the electrode being collected in a crucible thus forming a melt pool within the crucible; and b) solidifying the melt pool by heat exchange between the melt pool and a cooling fluid, the heat exchange applied serving to impose a mean solidification speed during step b) that is less than or equal to 45 μm/s and to obtain an ingot of low alloy steel.

2 . A method according to claim 1 , wherein carbon is present in the electrode before melting at a content by weight lying in the range 0.09% to 1.00%.

3 . A method according to claim 1 , wherein the electrode also includes, prior to melting, chromium at a content by weight lying in the range 0.10% to 5.50%.

4 . A method according to claim 1 , wherein the electrode also includes, prior to melting, molybdenum at a content by weight less than or equal to 5.00%.

5 . A method according to claim 1 , wherein, prior to melting, the electrode comprises iron together with:
carbon at a content by weight lying in the range 0.09% to 1.00%; manganese at a content by weight less than or equal to 6.00%; nickel at a content by weight less than or equal to 5.50%; silicon at a content by weight less than or equal to 3.00%; chromium at a content by weight lying in the range 0.10% to 5.50%; molybdenum at a content by weight less than or equal to 5.00%; and vanadium at a content by weight less than or equal to 5.00%.

6 . A method according to claim 1 , wherein a diameter of the melt pool lies in the range 650 mm to 1200 mm.

7 . A method according to claim 1 , wherein, before melting, the electrode is cylindrical in shape.

8 . A method according to claim 1 , wherein the mean solidification speed of the melt pool imposed during step b) is less than or equal to 40 μm/s.

9 . A method according to claim 1 , wherein the mean solidification speed imposed during step b) is greater than or equal to 9 μm/s.

10 . A part made of low alloy steel comprising iron and carbon, the part extending along a longitudinal axis, the part being such that when evaluated using the D method of the ASTM E 45-10 standard, the following results are obtained for analysis along the longitudinal axis:
the number of fields including type D inclusions of severity level equal to 0.5 is less than 5; no field including type D inclusions of severity level equal to 1 is obtained; and no field including type B inclusions of severity level equal to 0.5 is obtained.

11 . A part according to claim 10 , wherein when the part is evaluated using the method D of the ASTM E 45-10 standard, the following result is obtained when summing the three measurement results obtained along the longitudinal axis of the part and along the two axes perpendicular to the longitudinal axis:
the total number of fields including type D inclusions of severity level equal to 0.5 is less than or equal to 15.

12 . A part according to claim 10 , wherein carbon is present at a content by weight lying in the range 0.09% to 1.00%.

13 . A part according to claim 10 , further comprising chromium at a content by weight lying in the range 0.05% to 5.00%.

14 . A part according to claim 10 , further comprising molybdenum at a content by weight less than or equal to 5.00%.

15 . A part according to claim 10 , comprising iron together with:
carbon at a content by weight lying in the range 0.09% to 1.00%; manganese at a content by weight less than or equal to 5.00%; nickel at a content by weight less than or equal to 5.00%; silicon at a content by weight less than or equal to 3.00%; chromium at a content by weight lying in the range 0.05% to 5.00%; molybdenum at a content by weight less than or equal to 5.00%; and vanadium at a content by weight less than or equal to 5.00%.

Assignees

• Safran Aircraft Engines
• Safran Landing Systems

Inventors

• Ferrer Laurent
• Binot Nicolas

Classifications

• B22D27/04

  Influencing the temperature of the metal, e.g. by heating or cooling the mould · CPC title

• C22C38/46

  with vanadium · CPC title

• C22C38/02

  containing silicon · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• C22C38/44 Primary

  with molybdenum or tungsten · CPC title