Method for producing strip steel with a strength of more than 140 kg / mm² by cold tempering

Claims

Subsequent cold forming is carried out without intermediate annealing or at least without intermediate annealing at temperatures above 600°C. With this method, it is easily possible to achieve strengths of 140 kg / mm² and far above by using very large Overall cross-sectional reductions can be made without the strip breaking or tearing at the edges during cold rolling. According to the invention, the measures described above are used to process strip steel of various compositions, unalloyed or alloyed, to achieve a tensile strength exceeding 140 kg / mm² by cold rolling. Such strip steel, as used, for example, in spring elements (hardened Spring steel (for wood and metal saw blades and similar applications) has so far generally only been processed by hardening. and, if necessary, a subsequent tempering process. Since, however, the method according to the invention is simpler and the process according to it The fact that manufactured strip steel allows for excellent processing through cutting, punching, bending and pressing is the result of technical progress. given. Patent claims: i. Method for producing strip steel with a strength of more than 140 kg / mm2 by cold tempering, characterized by the combination a heat treatment of the strip hot-rolled above A3 in such a way that the rolled strip is removed from the rolling heat directly from the exit from the finished caliber up to approximately the reel, it is subjected to a harsh quenching process, which only occurs when the outside temperature of the strip reaches between The process is aborted at the Ar3 point and the lowest outside temperature that still allows coiling, whereupon the strip steel continues to be processed. After cooling, the resulting ring was coiled and immediately subjected to a balancing heat treatment at a temperature between approximately 350 and 5000°C. is subjected to — with subsequent cold forming without intermediate annealing or at least without intermediate annealing at temperatures above 600° C.

2. Application of the method according to claim ‡ for the production of so-called hardened spring steel strip, such as that used for springs It is used on the body.

3. Application of the method according to claim ‡ for the production of strip steel, which is processed into wood band saws and similar devices becomes.

4. Application of the method according to claim ‡ for the production of strip steel, which is processed into metal saws and similar devices. Publications considered: "Steel and Iron", 1942, pp. 1067 to 1073; Pomp, "Steel Wire", 2nd edition, 1952, pp. 218ff.; Puppe, "Rolling Mill Engineering", Volume 3, 1939, pp. 508 / 509. © IO& 575 / 2&Idigr; 5.61