Process for producing a component made of heat-treated cast iron

Patent metadata

Field	Value
Publication number	US-10337089-B2
Application number	US-201514806313-A
Country	US
Kind code	B2
Filing date	Jul 22, 2015
Priority date	Jul 25, 2014
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

The disclosure relates to a process for producing a hardened and tempered component made of specially heat-treated cast iron (e.g., AGI). According to the disclosure, a main body made of cast iron is prepared which may already be in the shape of an engine block. The main body may then be subjected to pre-machining, which may include forming one or more bores. Then, the main body may be hardened and tempered by a suitable heat treatment, such as a special heat treatment. After the disclosed heat treatment, post-processing of the component may follow, such as establishing the final dimensions.

First claim

What is claimed is:

1. A process comprising:
casting an engine block main body from a cast iron;
boring the main body to form a bore having a first shape;
heat treating the main body having the bore to establish an ausferritic microstructure of the main body and the bore having a second shape; and
machining the bore having the second shape after the heat treating step.

2. The process of claim 1 , wherein the main body is heated to a temperature of 850° C. to 950° C. during the heat treating step.

3. The process of claim 1 , further comprising cooling the main body in a salt bath after the heat treating step.

4. The process of claim 3 , wherein the salt bath has a temperature of 220° C. to 450° C.

5. The process of claim 1 , wherein the machining step includes threading the bore with a mechanical process to form a thread on the bore after the heat treating step.

6. The process of claim 1 , wherein the heat treating step establishes an at least 90% ausferritic microstructure in the main body.

7. The process of claim 1 , wherein the heat treating step establishes a 100% ausferritic microstructure.

8. The process of claim 1 , wherein the heat treating step is performed under a protective atmosphere.

9. The process of claim 1 , wherein the one bore is a through bore or a partial bore.

10. A process comprising:
casting an engine block main body from a cast iron;
boring the main body to form a bore having a first shape;
heat treating the main body to establish an at least 90% ausferritic microstructure in the main body and the bore having a second shape; and
machining the bore having the second shape after the heat treating step.

11. The process of claim 10 , wherein the main body is heated to a temperature of 850° C. to 950° C. during the heat treating step.

12. The process of claim 10 , further comprising cooling the main body in a salt bath after the heat treating step.

13. The process of claim 10 , wherein the machining step includes threading the bore with a mechanical process to form a thread on the bore after the heat treating step.

14. The process of claim 10 , wherein the heat treating step establishes a 100% ausferritic microstructure.

15. The process of claim 10 , wherein the heat treating step is performed under a protective atmosphere.

16. The process of claim 10 , wherein the bore is a through bore or a partial bore.

17. A process comprising:
casting an engine block from a cast iron;
boring the engine block to form a bore having a first shape;
heat treating the engine block having the bore at a temperature of 850° C. to 950° C. to establish an at least 90% ausferritic microstructure in the engine block and the bore having a second shape; and
machining the bore having the second shape after the heat treating step.

18. The process of claim 17 , wherein the machining step includes threading the bore with a mechanical process to form a thread on the bore after the heat treating step.

19. The process of claim 17 , further comprising machining the engine block after the heat treating step.

20. The process of claim 17 , further comprising machining surface regions of the engine block after the heat treating step.

Assignees

• Ford Global Tech Llc

Inventors

• Broda Maik
• Palazzolo Christopher K
• Ursavas Uemit
• Weber Glen
• Warkentin Matthias

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C21D5/00

  Heat treatments of cast-iron · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• C22C37/00 Primary

  Cast-iron alloys · CPC title

• C21D8/005

  Chemistry & Metallurgy · mapped topic