Process for manufacturing a composite assembly of ceramic and steel

• US 5,152,048 A
• Filed: 12/06/1990
• Issued: 10/06/1992
• Est. Priority Date: 12/22/1989
• Status: Expired due to Fees

• Current Assignee: Didier-Werke AG (RHI Magnesita NV)
• Original Assignee: Didier-Werke AG (RHI Magnesita NV)
• Inventors: Nebe, Ulrich, Winkelmann, Manfred, Bruckner, Raimund, Rothfuss, Hans
• Primary Examiner(s): Echols, P. W.
• Assistant Examiner(s): Bryant, David P.
• Application Number:
  US07/623,361
• Time in Patent Office: 670 Days
• Field of Search: 29/446, 29/447, 29/458, 219/10.43, 219/10.57
• US Class Current: 29/447
• CPC Class Codes: B22D 1/005 Injection assemblies therefor features relating to gas injection, provided on closures of the sliding gate type B22D41/42; provided on pouring nozzles B22D41/58; provided on closures of the stopper-rod type B22D41/186
• CPC Class Codes: B23P 11/025 by using heat or cold
• CPC Class Codes: C04B 2237/062 based on silica or silicates
• CPC Class Codes: C04B 2237/32 Ceramic
• CPC Class Codes: C04B 2237/406 Iron, e.g. steel
• CPC Class Codes: C04B 2237/76 Forming laminates or joined articles comprising at least one member in the form other than a sheet or disc, e.g. two tubes or a tube and a sheet or disc
• CPC Class Codes: C04B 2237/84 Joining of a first substrate with a second substrate at least partially inside the first substrate, where the bonding area is at the inside of the first substrate, e.g. one tube inside another tube
• CPC Class Codes: C04B 37/021 in a direct manner, e.g. direct copper bonding [DCB]
• CPC Class Codes: C04B 37/025 consisting of glass or ceramic material
• CPC Class Codes: Y10T 29/49863 with prestressing of part
• CPC Class Codes: Y10T 29/49865 by temperature differential [e.g., shrink fit]
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling

Abstract

A composite assembly includes a ceramic inner member and an outer shell member fit around the inner member. The outer shell member is heated and expanded, the two members then are mutually located at predetermined positions relative to each other, and the members are cooled such that the outer shell member shrinks onto the inner member. Heating of the outer shell member is achieved by an inductive heater to result in the predetermined temperature, after which the inner member is moved to the predetermined position thereof relative to the outer shell member, while the outer shell member is maintained at such predetermined temperature.

Claims

1. In a process of manufacturing a composite assembly including a ceramic inner member and a steel outer shell member fit around said inner member, wherein said outer shell member is heated and expanded, at least one of said members is moved relative to the other of said members such that said inner member is located at a predetermined position relative to said outer shell member, and said members are cooled such that said outer shell member shrinks onto said inner member, thereby forming a composite assembly, the improvement wherein:

said inner member is joined to said outer shell member in a relatively preliminary position;

thereafter said members are subjected to inductive heating to cause said outer shell member to be heated to a predetermined temperature and to be expanded relative to said inner member;

thereafter said inner member is moved relative to said outer shell member from said preliminary position until said inner member is located at said predetermined position relative to said thus expanded outer shell member; and

said outer shell member is maintained at said predetermined temperature and expanded during movement of said inner member by continuing and maintaining said inductive heating until said inner member is located at said predetermined position relative to said outer shell member.

2. The improvement claimed in claim 1, wherein said inner member is plate-shaped, and said outer shell member comprises a band shrunk onto the periphery of said plate-shaped member.

3. The improvement claimed in claim 1, wherein respective outer and inner surfaces of said inner member and said outer shell member are cylindrical.

4. The improvement claimed in claim 1, wherein respective outer and inner surfaces of said inner member and said outer shell member are conical.

5. The improvement claimed in claim 1, wherein respective outer and inner surfaces of said inner member and said outer shell member are frusto-conical.

6. The improvement claimed in claim 1, further comprising positioning between said members an intermediate layer of a material that is stable at said predetermined temperature and that will deform between confronting surfaces of said members, thereby accommodating any roughness or production tolerances of said surfaces.

7. The improvement claimed in claim 6, comprising positioning said layer on the outer surface of said inner member prior to joining of said members.

8. The improvement claimed in claim 6, comprising positioning said layer on the inner surface of said outer shell member prior to joining of said members.

9. The improvement claimed in claim 6, wherein said layer partially encloses the outer surface of said inner member.

10. The improvement claimed in claim 6, wherein said layer totally encloses the outer surface of said inner member.

11. The improvement claimed in claim 6, wherein said material of said layer is compressible.

12. The improvement claimed in claim 6, wherein said layer is in the form of a mat or is a molded member.

13. The improvement claimed in claim 6, wherein said material of said layer swells as a function of temperature.

14. The improvement claimed in claim 13, wherein said material of said layer comprises ceramic fibers and swellable vermiculite.

15. The improvement claimed in claim 14, wherein said ceramic fibers comprise aluminum silicate fibers.

16. The improvement claimed in claim 1, wherein said inner member comprises a gas flushing stone.

17. The improvement claimed in claim 1, wherein said inner member comprises a refractory member for use in discharging molten metal from a metallurgical vessel.

18. The improvement claimed in claim 1, wherein said inner member comprises a particle filter or a catalyst element.

19. In a process of manufacturing a composite assembly including a ceramic inner member and a steel outer shell member fit around said inner member, wherein said outer shell member is heated and expanded, at least one of said members is moved relative to the other of said members such that said inner member is located at a predetermined position relative to said outer shell member, and said members are cooled such that said outer shell member shrinks onto said inner member, thereby forming a composite assembly, the improvement wherein:

said inner member is joined to said outer shell member in a relatively preliminary position;

the thus preliminarily positioned members are inserted into an inductive heater operable by a frequency converter and said frequency converter is operated to subject said members to inductive heating to a predetermined temperature and thereby to expand said outer shell member relative to said inner member;

thereafter said inner member is moved from said preliminary position to said predetermined position relative to the thus expanded outer shell member;

said outer shell member is maintained at said predetermined temperature and expanded during movement of said inner member by continuing and maintaining said inductive heating until said inner member is located at said predetermined position relative to said outer shell member;

then operation of said frequency converter is stopped such that said outer shell member shrinks onto said inner member to form said composite assembly; and

said composite assembly of said inner member and said outer shell member is removed from said inductive heater.

20. The improvement claimed in claim 19, wherein said outer shell member and said inner member are introduced into said inductive heater from below, and said composite assembly is removed from said inductive heater from below.

21. The improvement claimed in claim 19, wherein said inductive heater is thermally insulated and is substantially sealed from all sides.

22. The improvement claimed in claim 19, wherein said outer shell member and said inner member are introduced into said inductive heater from above, and said composite assembly is removed from said inductive heater from above.

23. The improvement claimed in claim 19, wherein said predetermined temperature is from 500°

to 1000°

C.

24. The improvement claimed in claim 23, wherein said predetermined temperature is from 800°

to 950°

C.

25. The improvement claimed in claim 19, wherein said frequency converter is a medium frequency converter with a rated power of from 12 to 30 kW and a frequency of from 4 to 12 kHz.

26. The improvement claimed in claim 25, wherein said rated power is approximately 25 kW and said frequency is from 7 to 10 kHz.

27. The improvement claimed in claim 19, wherein said outer shell member is heated within said inductive heater for a time period of from 10 to 60 seconds before said inner member is moved to said predetermined position.

28. The improvement claimed in claim 27, wherein said time period is from 20 to 30 seconds.

29. The improvement claimed in claim 19, wherein said inner member is plate-shaped, and said outer shell member comprises a band shrunk onto the periphery of said plate-shaped member.

30. The improvement claimed in claim 19, wherein respective outer and inner surfaces of said inner member and said outer shell member are cylindrical.

31. The improvement claimed in claim 19, wherein respective outer and inner surfaces of said inner member and said outer shell member are conical.

32. The improvement claimed in claim 19, wherein respective outer and inner surfaces of said inner member and said outer shell member are frusto-conical.

33. The improvement claimed in claim 19, further comprising positioning between said members an intermediate layer of a material that is stable at said predetermined temperature and that will deform between confronting surfaces of said members, thereby accommodating any roughness or production tolerances of said surfaces.

34. The improvement claimed in claim 33, comprising positioning said layer on the outer surface of said inner member prior to joining of said members.

35. The improvement claimed in claim 33, comprising positioning said layer on the inner surface of said outer shell member prior to joining of said members.

36. The improvement claimed in claim 33, wherein said layer partially encloses the outer surface of said inner member.

37. The improvement claimed in claim 33, wherein said layer totally encloses the outer surface of said inner member.

38. The improvement claimed in claim 33, wherein said material of said layer is compressible.

39. The improvement claimed in claim 33, wherein said layer is in the form of a mat or is a molded member.

40. The improvement claimed in claim 33, wherein said material of said layer swells as a function of temperature.

41. The improvement claimed in claim 40, wherein said material of said layer comprises ceramic fibers and swellable vermiculite.

42. The improvement claimed in claim 41, wherein said ceramic fibers comprise aluminum silicate fibers.

43. The improvement claimed in claim 19, wherein said inner member comprises a gas flushing stone.

44. The improvement claimed in claim 19, wherein said inner member comprises a refractory member for use in discharging molten metal from a metallurgical vessel.

45. The improvement claimed in claim 19, wherein said inner member comprises a particle filter or a catalyst element.