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Publication numberUS3663316 A
Publication typeGrant
Publication dateMay 16, 1972
Filing dateDec 30, 1970
Priority dateJan 9, 1970
Also published asCA958921A, CA958921A1, DE2063940A1, DE2063940B2
Publication numberUS 3663316 A, US 3663316A, US-A-3663316, US3663316 A, US3663316A
InventorsAlfred Kulmburg
Original AssigneeBoehler & Co Ag Geb
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Steel for saw blades
US 3663316 A
Abstract
A sawblade consisting essentially of 0.6-0.9% C, 0.5-1.0% Si, 0.4-1.0% Mn, 0.4-1.0% Cr, 0.2-0.8% Mo, 0.3-1.0% Ni, at least one element in an amount of up to 0.3% selected from the group consisting of Ti or V, remainder iron and residual impurities; the microstructure of the sawblade being bainitic which has been hardened to a hardness range of 46-54 HRc.
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United States Patent Kulmburg [451 May 16, 1972 STEEL FOR SAW BLADES References Cited [72] Inventor: Alfred Kulmburg, Kapfenberg, Austria UNITED STATES PATENTS 73 Assignee; m; Bohler & Cm Akfi e eu haft 1,464,174 8/1923 Finkl 148/36 K f b Austria 1,660,790 2/1928 Herman 75/128 w 2,289,081 7/1942 Shortell et 21.... ..29/95 I Ffledi 1970 3,131,056 4/1964 0111161116161... 75/128 w 3,507,633 4/1970 Dewez ..29/183 1. N [2]] App 102 913 3,528,088 9/1970 Seghe711et a] ..148/36 x [30] Foreign Application Priority Data Primary Examiner-Charles N. Lovell Jan. 9, 1970 Austria ..Al62/70 Stem [57] ABSTRACT 52] 11.8. C1 ..148/36, 29/95, 30/166,

75 23 w 143 133 A sawblade consisting essentially of 0.60.9% C, 0.51.0% Si, 51 Int. Cl. ..C2ld 9 24, C22C 39/20, 823p 15/28 04-19% Mn, Cr, 02-03% 1 03-10% Ni, 4! [58] Field 61 Search ..75 128 v, 128 w; 148/36; least one element In an amount of p to 033% Selected from the group consisting of Ti or V, remainder iron and residual impurities; the microstructure of the sawblade being bainitic which has been hardened to a hardness range of 46-54 l-lR 3 Claims, N0 Drawings STEEL FOR SAW BLADES The invention relates to saw blades having baintic microstructure.

Generally in the fabrication of blades for power-saws, chain-saws, resaws, wide-band saws and wood/timber-saws, steels are used which possess on one hand a very hard surface and on the other a relatively tough core. To satisfy the requirements for this purpose, the German standard steel designations C 70 W1, C 87 WS and C 85 WS according ASl-W l) are suggested for the fabrication of such sawblades. For more severe service conditions the sawblades are fabricated of 80 Cr, V 2.

All these steels are used in quenched and tempered conditions. ln service saws blades must be wear-resistant as well as tough. These contrary properties are practically unobtainable in one tool. l-ligh wear resistance which means a high hardness usually means a such great loss in toughness which causes the sawblades to be replaced because the single chain-links of sawblades fracture. If one lowers the wear-resistance to obtain a higher toughness, then the service-life of the sawblades is very much reduced by early wear.

Extensive experiments have shown, that it is possible to use machine-saw-steels for sawblades having bainitic instead of martensitic microstructure in tempered condition. it was discovered, that steels with 0.6-0.9% C, 05-10% Si, 0.4-l.0% Mn, 0.4-l.0% Cr, 02-08% Mo, O.3l.0% Ni, possibly up to 0.3% Ti and/or V, remainder iron and residual impurities, possess when in bainitic hardened condition with a hardness of 46-54 Hr an optimal toughness.

For example, a steel with 0.68-0.73% C, O.80-1.00% Si, 0.35-0.50% Mn, OAS-0.60% Cr, 0.250.35% Mo, 0.55-0.75% Ni, remainder iron, was austenitised between 860880 C, followed by a treatment in a molten bath between 2903 30 C. After an isothermal holding time of approximately 60-90 minutes the cooling took place in still air. After this heat treatment the steel was in a bainitic condition.

The hardness of this steel was 51-52 HR.

The notch impact strength measured on five test pieces, was between 29 and 31 mkp/cm. For comparison, test pieces of the same steel were heat treated by the conventional method of quenching followed by tempering and were found to possess a hardness of 51-52 l-lRc as well. The notch impact strength of these samples however was only at the 2.5-3.5 mkp/cm The instant invention is therefor the use of particular steels having 06-09%C, 0.5-1.0% Si, 0.41.0% Mn, 0.4-1.0% Cr, 0.2-0.8 Mo, O.3l.0% Ni, possibly up to 0,3 Ti and/or V, remainder iron and residual impurities, in bainitic hardened condition with a hardness of 46-54 l-lRc for the manufacture of chain saws.

This steel is also very suitable for long-band-saws, which are particularly stressed by buckling at the sides.

Although the invention has been described in detail, it is to be understood that this does not delimit the invention. The spirit and scope of this invention is limited only by the language of the appended claims.

What we claim is:

1. A sawblade consisting essentially of 0.6-0.9% C, 0.5-1.0% Si, 0.4-1.0% Mn, O.4l.0% Cr, 0.20.8% Mo, 0.3-1 .0% Ni, at least one element in an amount of up to 0.3% selected from the group consisting of Ti or V, remainder iron and residual impurities; the microstructure of the sawblade being bainitic which has been hardened to a hardness range of 46-54 HR.

2. The sawblade as claimed in claim 1 wherein the composition is 0.68-0.73% C, 0.80-1.00% Si, 0.35-0.50% Mn,.

0.550.75% Ni, the

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1464174 *Feb 11, 1922Aug 7, 1923Finkl & Sons CoAir-hardening steel alloy
US1660790 *May 27, 1926Feb 28, 1928Alloy Steel CorpProcess of preparing alloy steel for die blocks and other purposes
US2289081 *Aug 30, 1938Jul 7, 1942Hawkridge Brothers CompanyHack saw blade
US3131056 *Apr 20, 1962Apr 28, 1964Int Nickel CoRolling contact bearing steels and process for heat treating the same
US3507633 *Apr 17, 1967Apr 21, 1970Dewez Fernand J JrCircular saw blade of chromium nickel steel with an oxide coat
US3528088 *Jan 17, 1968Sep 8, 1970Hilti AgAnchoring device of spring steel and method for imparting the device with a bainitic structure
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3859146 *Jun 1, 1973Jan 7, 1975Ceskoslovenska Akademie VedSteel composition, particularly for anti-friction bearings
US4343661 *Apr 21, 1980Aug 10, 1982Caterpillar Tractor Co.Method of making a low temperature bainite steel alloy gear
US4645715 *Mar 17, 1982Feb 24, 1987Energy Conversion Devices, Inc.Coating composition and method
US5185162 *Jun 17, 1991Feb 9, 1993Xaloy, IncorporatedCorrosion and wear resistant bimetallic cylinder
US5651938 *May 1, 1995Jul 29, 1997Blount, Inc.High strength steel composition having enhanced low temperature toughness
US5772957 *Aug 23, 1996Jun 30, 1998Blount, Inc.High strength steel composition having enhanced low temperature toughness
US20040182216 *Jul 31, 2003Sep 23, 2004Electrolux Professional Outdoor Products, Inc.Coating for a chainsaw chain
EP1130126A2 *Feb 27, 2001Sep 5, 2001Böhler Miller Messer und Sägen GmbHBlade body for thin circular saws
EP1130126A3 *Feb 27, 2001Jul 2, 2003Böhler Miller Messer und Sägen GmbHBlade body for thin circular saws
Classifications
U.S. Classification148/335, 407/119, 148/905, 83/835
International ClassificationB23D61/12
Cooperative ClassificationY10S148/905, B23D61/127
European ClassificationB23D61/12M