Process for the cryogenic treatment of metal containing materials

• US 5,875,636 A
• Filed: 10/01/1997
• Issued: 03/02/1999
• Est. Priority Date: 10/01/1997
• Status: Expired due to Fees

• Current Assignee: NU-BIT, Inc.
• Original Assignee: NU-BIT, Inc.
• Inventors: Kamody, Dennis J.
• Primary Examiner(s): CAPOSSELA, RONALD C
• Application Number:
  US08/941,739
• Time in Patent Office: 517 Days
• Field of Search: 62/64, 62/78
• US Class Current: 62/64
• CPC Class Codes: C21D 6/04 Hardening by cooling below 0 degrees Celsius
• CPC Class Codes: C22C 1/11 Making amorphous alloys

Abstract

A process for treating an article of metal containing material having a minimum cross-sectional dimension. The process includes providing the article at ambient temperature or below and completely immersing the article in a cryogenic fluid over a time period at least equal to 10 minutes times a value of the minimum cross-sectional dimension in inches. The process further includes withdrawing the article from contact with the cryogenic fluid, and immediately subjecting the article to a flow of gaseous fluid sufficient to raise the temperature of the article until the article reaches ambient temperature.

Claims

1. A process for treating an article of metal containing material having a minimum cross-sectional dimension, the process comprising

providing the article at ambient temperature or below, completely immersing the article in a cryogenic fluid over a time period at least equal to t, where t is defined by:

space="preserve" listing-type="equation">t (min.=(k minutes/inch cross-section.sub.min)(inches in minimium cross-section for article)

where k is at least 10

withdrawing the article from contact with the cryogenic fluid, and

immediately subjecting the article to a flow of gaseous fluid sufficient to raise the temperature of the article until the article reaches ambient temperature.

2. The process of claim 1 wherein the immersion of the article into the cryogenic fluid is continuous.

3. The process of claim 2 wherein the immersion of the article into the cryogenic fluid is at a constant rate.

4. The process of claim 1 wherein the immersion into the cryogenic fluid is discontinuous comprising partially immersing the article into the cryogenic fluid, followed by at least one hold step followed by a further partial immersion of the article into the cryogenic fluid.

5. The process of claim 1 wherein the metal containing material of the article includes steel.

6. The process of claim 1 wherein the cryogenic fluid includes liquid nitrogen.

7. The process of claim 6 wherein the metal containing material of the article includes steel.

8. The process in accordance with claim 1 wherein the gaseous fluid is ambient air.

9. The process in accordance with claim 1 wherein the article is immersed with a major axis thereof oblique to a surface of the cryogenic fluid.