Tool for textiles and production method for same

Patent metadata

Field	Value
Publication number	US-10487429-B2
Application number	US-201415106006-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Dec 19, 2013
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

The tool (10) for textiles according to the invention consists of chromium steel, into which carbon has been embedded in locally varying amounts during a carbonizing process. Thermal treatment achieves a formation of martensite with the maximum achievable hardness, in particular in those zones in which larger carbon fractions have been introduced. A tool for textiles with zones of differing hardnesses can thus be produced without having to subject the individual zones with differing hardnesses to different process conditions during the production process. The hardness is controlled on the basis of the degree of deformation of the tool for textiles.

First claim

The invention claimed is:

1. A tool ( 10 ) having a size within a range of thickness of needles for textiles, the tool comprising:
a base body including a chromium steel and portions ( 14 , 15 ) whose material displays differing degrees of deformation,
said base body having a chromium content of 11% to 30%, an aluminum content of less than 0.3 percent by weight, a copper content of less than 0.4 percent by weight, and a total carbon content of more than 0.8% in at least one surface zone;
wherein the base body consists essentially of a carburized chromium steel;
wherein the base body has an initial carbon content of not more than 0.7%;
wherein less than 20% of individual carbide crystals at a surface of the tool are connected by fusible links.

2. The tool for textiles as in claim 1 wherein the base body consists essentially of a chromium steel having a nickel content of not more than 12%.

3. The tool for textiles as in claim 1 , wherein the base body contains chromium carbide.

4. The tool for textiles as in claim 1 , wherein the base body has—in zones close to the tool's surface—a higher carbon content than in zones remote from the tool's surface.

5. The tool for textiles as in claim 1 , wherein the base body includes full-hardness martensite.

6. The tool for textiles as in claim 1 , wherein the base body is elongated and has, along its length, portions having different degrees of deformation and/or different surface/volume ratios.

7. The tool for textiles as in claim 6 , wherein the base body has, in the zones displaying greater degrees of deformation and or greater surface/volume ratios, a greater hardness than in zones displaying lower degrees of deformation and/or lower surface/volume ratios.

8. The tool for textiles as in claim 1 , wherein the base body is less deeply hardened in portions displaying lower degrees of deformation than in portions displaying greater degrees of deformation.

9. The tool for textiles as in claim 1 , wherein the base body consists essentially of a carburized chromium steel having an initial carbon content of not more than 0.5%.

10. The tool for textiles as in claim 9 , wherein the base body consists essentially of a carburized chromium steel having an initial carbon content of not more than 0.3%.

11. A method for providing tools ( 10 ) having a size within a range of thickness of needles for textiles, the method comprising:
deforming various portions of a tool blank of a chromium steel with a base body having a chromium content of at least 11%, an aluminum content of below 0.3 percent by weight, a copper content of below 0.4 percent by weight, and a total carbon content of more than 0.8% in at least one surface zone, wherein the base body consists essentially of a carburized chromium steel, wherein the base body has an initial carbon content of not more than 0.7%, and wherein less than 20% of individual carbide crystals at a surface of the tool are connected by fusible links, with differing degrees of deformation for production of at least one working portion ( 14 ) and one shank portion ( 15 ),
carburizing the tool blank under chromium carbide formation,
applying a hardening temperature to the carburized tool blank,
quenching the tool blank for formation of martensite.

12. The method as in claim 11 , wherein the deformation of the tool blank in the working portion ( 14 ) includes a flow of the material in an entire cross-section of the tool and/or an ablation of material.

13. The method as in claim 11 , wherein the carburizing takes place at a temperature between 900° C. and 1050° C.

14. The method as in claim 11 , wherein the carburizing is performed by a carbon-containing carrier gas.

15. The method as in claim 11 , wherein the applying the hardening is performed at a temperature that is higher than, equal to or lower than the temperature used for carburization.

16. The method as in claim 11 , wherein the quenching comprises a freezing of the tool blank.

17. The method as in claim 11 , wherein the base body consists essentially of a carburized chromium steel having an initial carbon content of not more than 0.7%.

Assignees

• Groz Beckert Kg

Inventors

• Schwarz Simone
• Durst Frank-Martin
• Zeller Richard

Classifications

• C21D2221/10

  Differential treatment of inner with respect to outer regions, e.g. core and periphery, respectively · CPC title

• C21D7/10

  of the whole cross-section, e.g. of concrete reinforcing bars · CPC title

• B21G1/006 Primary

  Special treatments of pins or needles, e.g. annealing, straightening · CPC title

• B21G1/003

  Needles for special purposes, e.g. knitting, crochet, hat-pins · CPC title

• C21D1/06

  Surface hardening · CPC title