Claims
- 1. A method of heat treating fabricated metal parts comprising the steps of:
- (A) heating the parts to a temperature above a metallurgical transformation range;
- (B) placing the parts in a heated, agitated quench bath comprising an aqueous solution of about 10% to 25% by volume of polyvinylpyrrolidone having a molecular weight in the range of between 900,000 and 3,000,000;
- (C) removing the parts from the quench bath; and
- (D) water washing the parts to substantially remove any polymeric film formed on the parts in the quench bath.
- 2. A method as defined in claim 1 wherein the concentration of the polyvinylpyrrolidone is approximately 25% by volume.
- 3. A method as defined in claim 1 wherein the polyvinylpyrrolidone has a molecular weight in the range of between about 1,270,000 and 2,240,000.
- 4. A method as defined in claim 1 further including the step of recovering the polyvinylpyrrolidone from the wash water.
- 5. A method as defined in claim 1 wherein the washing step is performed by a power spray at a pressure in the range of about 20 to 45 psi.
- 6. A method as defined in claim 1, wherein the bath temperature is about 130.degree. F.
- 7. A method of heat treating fabricated metal parts comprising the steps of:
- (A) heating the parts to a temperature above a metallurgical transformation temperature range;
- (B) placing the parts in a heated, agitated quench bath consisting essentially, by weight, of:
- (i) about 7% of polyvinylpyrrolidone having a molecular weight in the range of between 900,000 and 3,000,000;
- (ii) about 7% of an amine-neutralized, carboxylic acid;
- (iii) about 7% of triethanolamine; and
- (iv) the balance water;
- (C) removing the parts from the quench bath; and
- (D) water washing the parts to substantially remove any polymeric film formed on the parts in the quench bath.
- 8. A method as defined in claim 7 wherein the polyvinylpyrrolidone has a molecular weight in the range of between about 1,270,000 and 2,240,000.
- 9. A method as defined in claim 7 further including the step of recovering the polyvinylpyrrolidone, amine neutralized carboxylic acid and triethanolamine from the wash water.
- 10. A method of heating treating fabricated metal parts comprising the steps of:
- (A) heating the parts to a temperature above a metallurgical transformation temperature range;
- (B) placing the parts in a heated, agitated quench bath consisting essentially, by weight, of:
- (i) about 20% of polyvinylpyrrolidone having a molecular weight in the range between 900,000 and 3,000,000;
- (ii) about 0.8% borax;
- (iii) about 0.2% sodium nitrite; and
- (iv) the balance water;
- (C) removing the parts from the quench bath; and
- (D) water washing the parts to substantially remove any polymeric film formed on the parts in the quench bath.
- 11. A method as defined in claim 10 wherein said quench bath also includes about 0.5%, by weight, of a bacteriocidal agent.
- 12. A method as defined in claim 10 wherein the polyvinylpyrrolidone has a molecular weight in the range of between about 1,270,000 and 2,240,000.
- 13. A method as defined in claim 10 further including the step of recovering the polyvinylpyrrolidone, borax and sodium nitrite from the wash water.
- 14. A method for controlling the microstructure of carbon steel objects by immersing said objects, after preheating in a water based polymeric bath wherein the improvement comprises constituting said bath as an aqueous solution comprising about 7-20% by weight polyvinylpyrrolidone having a molecular weight between about 900,000 and 3,000,000 and the balance water.
- 15. The method of claim 14 wherein the quenchant is constituted of said polyvinylpyrrolidone and water and, in addition, at least about 7% weight of each triethanolamine and an amine neutralized, carboxylic acid rust inhibitor.
- 16. The method of claim 15 including the later step of water washing the objects using a power spray at a pressure in the range of about 20 to 40 psi to remove residual polyvinylpyrrolidone from the objects.
RELATED APPLICATION
This application is a continuation-in-part of Ser. No. 819,204 filed Jan. 15, 1986 now abandoned which is a continuation-in-part of Ser. No. 766,598 filed Aug. 19, 1985, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3902929 |
Meszaros |
Sep 1975 |
|
4087290 |
Kopietz et al. |
May 1978 |
|
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
819204 |
Jan 1986 |
|
Parent |
766598 |
Aug 1985 |
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