Hand-held work implement and process for producing a braking device of a hand-held work implement

Abstract

A hand-held work implement having a tool has a braking device for the tool that includes a brake band which wraps around a brake drum. The brake band and the brake drum undergo friction as they move relative to one another during braking. At least one of the band or drum comprises an austenitic steel, a duplex steel, super duplex steel, a nickel-base alloy or a cobalt-base alloy and has a base body and a marginal layer. The hardness of the marginal layer is approximately 150% to approximately 600% of the hardness of the base body and the carbide proportion in the marginal layer is less than approximately 0.5% by weight. A process for production of the foregoing includes diffusing carbon and/or nitrogen into a marginal layer at a temperature of less than 500 C.

Claims

1. A hand-held work implement comprising a tool and a braking device for the tool, wherein the braking device comprises a brake band, which wraps around a brake drum, wherein the brake band and the brake drum form a first part and a second part undergoing friction which move relative to one another during the braking operation, wherein the first part undergoing friction is an austenitic steel, a duplex steel, super duplex steel, a nickel-base alloy or a cobalt-base alloy, wherein the first part undergoing friction has a base body and a marginal layer, wherein the base body and the marginal layer comprise the same base material, wherein the marginal layer comprises diffused carbon or nitrogen embedded in a matrix of the base material such that the hardness of the marginal layer is approximately 150% to approximately 600% of the hardness of the base body, and wherein a carbide proportion in the marginal layer is less than approximately 0.5% by weight.

2. The hand-held work implement according to claim 1, wherein the marginal layer has a thickness of approximately 5 m to approximately 50 m.

3. The hand-held work implement according to claim 1, wherein a nitride proportion in the marginal layer is less than approximately 1%.

4. A hand-held work implement comprising a tool and a braking device for the tool, wherein the braking device comprises a brake band, which wraps around a brake drum, wherein the brake band and the brake drum form a first part and a second part undergoing friction which move relative to one another during the braking operation, wherein the first part undergoing friction is an austenitic steel, a duplex steel, super duplex steel, a nickel-base alloy or a cobalt-base alloy, wherein the first part undergoing friction has a base body and a marginal layer, wherein the base body and the marginal layer comprise the same base material, wherein the marginal layer comprises diffused carbon or nitrogen embedded in a matrix of the base material such that the hardness of the marginal layer is approximately 150% to approximately 600% of the hardness of the base body, and wherein a carbide proportion in the marginal layer is less than approximately 0.5% by weight, wherein a carbon content in the marginal layer is approximately 1% by weight to approximately 7% by weight.

5. The hand-held work implement according to claim 1, wherein a nitrogen proportion in the marginal layer is approximately 5% by weight to approximately 12% by weight.

6. The hand-held work implement according to claim 1, wherein the first part undergoing friction is the brake band.

7. The hand-held work implement according to claim 1, wherein the first part undergoing friction is the brake drum.

8. The hand-held work implement according to claim 1, wherein the first part undergoing friction is a stainless, austenitic steel.

9. The hand-held work implement according to claim 1, wherein the second part undergoing friction is a steel with a body-centered cubic lattice structure.

10. A process for producing a braking device of a hand-held work implement, wherein the work implement has a tool and a braking device for the tool, wherein the braking device comprises a brake band, which wraps around a brake drum, wherein the brake band and the brake drum form a first part and a second part undergoing friction which move relative to one another during the braking operation, wherein a first part undergoing friction is an austenitic steel, a duplex steel, a super duplex steel, a nickel-base alloy or a cobalt-base alloy, and carbon and/or nitrogen is made to diffuse into a marginal layer of the first part undergoing friction at a temperature of less than 500 C.

11. The process according to claim 10, wherein the diffusion is effected over a period of time of more than 48 hours.

12. The process according to claim 10, wherein the diffusion is effected over a period of time of more than 96 hours.

13. The process according to claim 10, wherein only carbon is made to diffuse into the marginal layer.

14. The hand-held work implement according to claim 1, wherein the second part undergoing friction is a steel with a tetragonally distorted lattice structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the invention will be explained hereinbelow with reference to the drawing, in which:

(2) FIG. 1 shows a schematic side view of a power saw,

(3) FIG. 2 shows a perspective illustration of the brake band of the power saw shown in FIG. 1,

(4) FIG. 3 shows a side view of the brake band shown in FIG. 2,

(5) FIG. 4 shows a schematic illustration of the marginal layer of the brake band,

(6) FIG. 5 shows a schematic illustration of a marginal layer of a brake drum.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(7) Turning to the figures of drawing, the power saw 1 shown in FIG. 1 has a housing 2, on which a rear handle 3 and a tubular handle 4 for guiding the power saw 1 are fixed. The power saw 1 has a guide bar 5, which protrudes forwards at the front side of the housing 2 remote from the rear handle 3. A saw chain 6 is arranged circumferentially on the guide bar 5. The saw chain 6 is driven in a circulating manner by a combustion engine 7 arranged in the housing 2. Instead of the combustion engine 7, provision can also be made of an electric motor, which is advantageously supplied with energy via a power cable, by a battery or by a rechargeable battery. The combustion engine 7 is in the form of a single-cylinder engine. Advantageously, the combustion engine 7 is a two-stroke engine or a mixture-lubricated four-stroke engine. The combustion engine 7 has a crankshaft 8, which is connected via a centrifugal clutch 9 to a pinion, which is not shown in FIG. 1 and drives the saw chain 6.

(8) The centrifugal clutch 9 has a brake drum 12, against which centrifugal weights 24 of the centrifugal clutch 9 are pressed during operation on account of the centrifugal force. The brake drum 12 is part of a braking device 10 of the power saw 1. In addition to the brake drum 12, the braking device 10 comprises a brake band 13, which wraps around the brake drum 12 on the external circumference thereof. In the non-activated state, the brake band 13 lies at a small radial distance from the circumference of the brake drum 12. When the braking device 10 is activated, the loop formed by the brake band 13 is tightened and the brake band 13 is pressed against the circumference of the brake drum 12, such that the brake drum 12 is stopped. Provision can also be made for the brake band 13 to only partially wrap around the brake drum 12.

(9) To activate the braking device 10, a hand protector 11 is mounted on the housing 2, extending on that side of the tubular handle 4 which faces towards the guide bar 5. The hand protector 11 activates the braking device 10 via a toggle-lever mechanism 25. The toggle-lever mechanism 25 is held in its two end positions by a spring 14, i.e. the non-activated position and the activated position of the braking device 10. The toggle-lever mechanism 25 engages on a release end 19, also shown in FIG. 2 and FIG. 3, of the brake band 13, and pulls the brake band 13 tight about the brake drum 12 when the braking device 10 is released. The other end, i.e. the fastening end 18 of the brake band 13, is fixed to the housing 2 of the power saw 1. As shown in FIG. 2, a bolt 16 is provided on the brake band 13 at the fastening end 18 and can be used to fix the brake band 13 in the housing 2.

(10) The power saw 1 shown in FIG. 1 moreover has an additional braking device 15 for activating the braking device 10. The additional braking device 15 serves as a run-down brake for the saw chain 6, and is activated upon release of a throttle lever 22 mounted on the rear handle 3.

(11) As shown in FIG. 3, the brake band 13 has, on its inner side facing towards the brake drum 12, a contact surface 17, with which the brake band 13 bears, in the tightened state of the braking device 10, against the external circumference of the brake drum 12, and as a result decelerates the latter. The contact surface 17 is formed on a marginal layer 21 of the brake band, this being shown schematically in FIG. 4.

(12) As shown in FIG. 4, the brake band 13 has a base body 20, on which the marginal layer 21 is formed. The base body 20 is a stainless, austenitic steel, a duplex steel, a super duplex steel, a nickel-base alloy or a cobalt-base alloy, in particular a stellite alloy.

(13) Embodiments of the present application may utilize an austenitic steel for the base body 20 of the brake band 13, for example, one of the following alloys: 1.4301; 1.4310; 1.4305; 1.4401; 1.4404; 1.4435; 1.4571; 1.4580; 1.4944; 1.4980; 1.4539; AISI 316; AISI 304.

(14) Further embodiments of the present application may utilize the composition of these steels and of further steels suitable for the base body 20 of the brake band, as listed in the table below:

(15) TABLE-US-00001 Mat. Chemical analysis in % by weight No. C Si Mn P S Cr Mo Ni Fe Other 1.4003 0.03 1.00 1.50 0.040 0.015 10.5-12.5 0.30-1.00 Rem. N 0.030 1.4006 0.08-0.15 1.00 1.50 0.040 0.015 11.5-13.5 0.75 Rem. 1.4016 0.08 1.00 1.00 0.040 0.015 16.0-18.0 Rem. 1.4108 0.25-0.35 1.00 1.00 0.030 0.025 14.0-16.0 0.85-1.10 0.50 Rem. N 0.30-0.50 1.4162 0.04 1.00 4.0-6.0 0.040 0.015 21.0-22.0 0.10-0.80 1.35-1.70 Rem. Cu 0.10-0.80; N 0.20-0.25 1.4301 0.07 1.00 2.00 0.045 0.015 17.5-19.5 8.00-10.5 Rem. N 0.11 1.4305 0.10 1.00 2.00 0.045 0.15-0.35 17.0-19.0 8.00-10.0 Rem. Cu 1.00; N 0.11 1.4306 0.030 1.00 2.00 0.045 0.015 18.0-22.0 10.0-12.0 Rem. N 0.11 1.4307 0.030 1.00 2.00 0.045 0.015 17.5-19.5 8.00-10.5 Rem. N 0.11 1.4310 0.05-0.15 2.00 2.00 0.045 0.015 16.0-19.0 0.80 6.00-9.50 Rem. N 0.11 1.4319 0.070 1.00 2.00 0.045 0.030 16.0-18.0 6.00-8.00 Rem. N 0.11 1.4362 0.030 1.0 2.0 0.035 0.015 22.0-24.0 0.10-0.60 3.50-5.50 Rem. Cu 0.10-0.60; N 0.05-0.20 1.4401 0.07 1.00 2.00 0.045 0.015 16.5-18.5 2.00-2.50 10.0-13.0 Rem. N 0.11 1.4404 0.07 1.00 2.00 0.045 0.015 16.5-18.5 2.00-2.50 10.0-13.0 Rem. N 0.11 1.4410 0.030 1.00 2.00 0.035 0.015 24.0-26.0 3.00-5.00 6.00-8.00 Rem. N 0.24-0.35 1.4429 0.030 1.00 2.00 0.045 0.015 16.5-18.5 2.5-3.0 11.0-14.0 Rem. N 0.12-0.22 1.4435 0.030 1.00 2.00 0.045 0.015 17.0-19.0 2.50-3.00 12.5-15.0 Rem. N 0.11 1.4436 0.05 1.00 2.00 0.045 0.015 16.5-18.5 2.50-3.00 10.5-13.0 Rem. N 0.11 1.4460 0.05 1.00 2.00 0.035 0.015 25.0-28.0 1.3-2.0 4.50-6.50 Rem. N 0.05-0.20 1.4462 0.030 1.00 2.00 0.035 0.015 21.0-23.0 2.50-3.50 4.50-6.50 Rem. N 0.10-0.22 1.4501 0.03 1.00 1.00 0.035 0.015 24.0-26.0 3.00-4.00 6.00-8.00 Rem. Cu 0.50-1.00; N 0.20-0.30; W 0.50-1.00 1.4507 0.030 0.70 2.00 0.035 0.015 24.0-26.0 2.70-4.00 5.50-7.50 Rem. N 0.15-0.30 1.4529 0.02 0.50 1.00 0.030 0.01 19.0-21.0 6.00-7.00 24.0-26.0 Rem. N 0.15-0.25 Cu 0.50-1.50; 1.4534 0.05 0.10 0.10 0.010 0.008 12.25-13.25 2.00-2.50 7.50-8.50 Rem. Ti 0.1; N 0.01; Al 0.80-1.35 1.4539 0.02 0.70 2.00 0.030 0.010 19.0-21.0 4.00-5.00 24.0-26.0 Rem. Cu 1.20-2.00; N 0.15 1.4541 0.08 1.00 2.00 0.045 0.015 17.0-19.0 9.00-12.00 Ti (5xC) 0.70 1.4542 0.07 0.70 1.50 0.04 0.015 15.0-17.0 0.60 3.00-5.00 Rem. Nb 5xC - 0.45; Cu 3.00-5.00 1.4545 0.07 1.00 1.00 0.030 0.015 15.0-15.5 0.50 3.00-5.50 Rem. Nb (5xC) 0.45; Cu 2.50-4.50 1.4547 0.02 0.70 1.00 0.030 0.01 19.5-20.5 6.00-7.00 17.5-18.5 Rem. Cu 0.50-1.00; N 0.18-0.25 1.4562 0.15 0.30 2.00 0.02* 0.01* 26.0-28.0 6.00-7.00 30.0-32.0 Rem. Cu 1.00-1.40; N 0.15-0.25 1.4563 0.02 0.70 2.00 0.030 0.01 26.0-28.0 3.00-4.00 30.0-32.0 Rem. Cu 0.70-1.50; N 0.11 1.4565 0.03 1.00 5.00-7.00 0.030 0.015 24.0-26.0 4.00-5.00 16.0-19.0 Rem. N 0.30-0.60, Nb 0.150 1.4567 0.04 1.00 2.00 0.045 0.015 17.0-19.0 8.50-10.5 Rem. Cu 3.00-4.00; N 0.11 1.4568 0.09 0.70 1.00 0.004* 0.015* 16.0-18.0 6.50-7.80 Rem. Al 0.70-1.50 1.4571 0.08 1.00 2.00 0.045 0.015 16.5-18.5 2.00-2.50 10.0-13.5 Rem. Ti 5; C 0.70 1.4580 0.08 1.00 2.00 0.045 0.015 16.5-18.5 2.00-2.50 10.5-13.5 Rem. Nb (10xC) 1.00 1.4591 0.015 0.50 2.00 0.020 0.010 31.0-35.0 0.50-2.00 30.0-33.0 Rem. Cu 0.30-1.20; N 0.35-0.60 1.4652 0.02 0.50 2.00-4.00 0.030 0.005 23.0-25.0 7.00-8.00 21.0-23.0 Rem. Cu 0.30-0.60; N 0.45-0.55 1.4662 0.02 0.70 1.00-3.00 20.0-24.0 1.50-3.50 3.50-9.00 Rem. N 0.27 1.4845 0.10 1.50 2.00 0.045 0.015 24.0-26.0 19.0-22.0 Rem. N 0.11 1.4847 0.08 1.00 1.00 0.030 0.015 18.0-22.0 18.0-22.0 Rem. Al 0.60; Ti 0.60 1.4944 0.08 1.00 2.00 0.030 0.015 13.5-16.0 1.00-1.50 24.0-27.0 Rem. V 0.10-0.50, Al 0.35; B 0.003-0.010, Ti 1.90-2.30 1.4980 0.03-0.08 1.00 1.00-2.00 0.025 0.015 13.5-16.0 1.00-1.50 24.0-27.0 Rem. Alg/tot 0.35; B 0.003-0.010; V 0.10-0.50; Ti 1.90-2.30

(16) The standards to which the designations of the steels mentioned in the table are directed are listed in the table below, with in each case German or European designations and standards and American designations and standards being indicated:

(17) TABLE-US-00002 Mat. No. Material Standard 1.4003 X2CrNi12 EN 10028-7: 2008-02; X2Cr11 UNS; ASTM A 240; S41050 1.4006 X12Cr13 DIN EN 10088-1: 2005-09; EN 10088-4/-5 X10Cr13 AISI, UNS, AMS 5350, 5504, 5505, 5591, 5613, 410, S41000 5776, 5777, 5867, QQ-S-763, ASME SA-194, 240, 268, 479, ASTM A 1012, 1021, 1028, 182, 193, 194, 240, 268, 276, 314, 336, 473, 479, 493, 511, 580, 815, 837, 982, 988, ASTM F 1079, 116, 1613, 2215, 2281, 593, 594, 738, 836, 837, 899, SAE J 405, 467 1.4016 X6Cr17 DIN EN 10088-1: 2005-09 430 AISI, UNS, AMS 5503, 5627, AMS-QQ-S-763, ASME S43000 SA-182, 240, 268, 479, ASTM A 240, 268, 276, 314, 473, 479, 493, 511, 580, 815, ASTM F 2215, 2281, 594, 738, 836, 593, SAE J 405, 412 1.4108 X30CrMoN15-1 SEW 400 AMS 5898* AMS 1.4162 X2CrMnNiN21-5-1 VdTUV-Wb1 556: 2011-09 Duplex DIN EN 10088-4; -5: 2010-01 4.4301 X5CrNi18-10 EN 10028-7; EN 10088-1; -2; -3; -4; -5; EN X5CrNi18 9 (V2A) 10151; 304, S30400 EN10216-5; EN 10217-7; EN 10222-5; EN 10250-4; EN 10263-5; EN 10264-4; EN 10269; EN 10272; EN 10296-2; EN 10297-2; EN 10312; 5512-3 AISI, UNS, ASME, SA-240, SAE 1.4305 X8CrNiS18-9/ EN 10088-1; -2; -3; -5; EN 10297-2; EN 10312 X10CrNiS18 9 AISI, UNS, AMS 5640, ASME SA-194, ASME SA-320, 303, S30300, Type 1, 8F, ASTM A 194, 314, 320, 473, 581, 582, 895, ASTM 8FA, B8F, B8FA, 30303 F 593, 594, 738, 836, 837, 880, 899, SAE J 412 1.4306 X2CrNi19-11 DIN EN 10028-7: 2008-02 304L, S30403 UNS, ASTM A 240, AISI, ASME SA-240, SAE 1.4307 X2CrNi18-9 DIN EN 10272: 2008-01 304L, S30403 UNS, ASTM A 479, AISI, ASME SA-479, SAE 1.4310 X10CrNi18-8/ EN 10088-1; -2; -3; EN 10151; EN 10263-5; X12CrNi17 7/ EN 10264-4; EN 10270-3; EN 10312 301, S30100, MT301, 30301 AISI, UNS, AMS 5517, 5518, 5519, 5901, 5902, ASTM A 240, 554, 666, ASTM F 899, SAE J 405, 412 1.4319 X5CrNi17-7 EN 10088-1: 2005-09; EN 10312 X3CrNiN 17-8 AISI, ISO TS 15510 302 1.4362 X2CrNiN23-4 DIN EN 10028-7: 2008-02 SAF2304, S32304 AISI, ASTM A 240, UNS Duplex 1.4401 X5CrNiMo17-12-2 EN 10028-7; EN 10088-1; -2; -3; -4; -5; EN X5CrNiMo18 10 10151; (V4A) EN 10216-5; EN 10217-7; EN 10222-5; EN 10250-4; 316, S31600 EN 10263-5; EN 10264-4; EN 10269; EN 10270-3; EN 10272; EN 10296-2; EN 10297-2; EN 10312; 5512-3 AISI; UNS, ASTM A 240, ASME SA-240, SAE 1.4404 X2CrNiMo17-12-2 DIN EN 10028-7: 2008-02 X2CrNiMo17-13-2 AISI; UNS, ASTM A 240, ASME SA-240, SAE 316L, S31603 1.4410 X2CrNiMoN25-7-4 EN 10028-7 Super Duplex ASTM A240, UNS SAF 2507, S32750 1.4429 X2CrNiMoN17-13-3 DIN EN 10028-7: 2008-02 316LN, S31653 AISI, ASTM A 240, SAE, UNS 1.4435 X2CrNiMo18-14-3 EN 10028-7; EN 10088-1; -2; -3; -4; -5; EN 316L, S31603 10216-5; EN 10217-7; EN 10222-5; EN 10250-4; EN 10272; EN 10296-2; EN 10297-2; EN 10312 AISI, UNS, ASTM A 240, ASME SA-240, SAE 1.4436 X3CrNiMo17-13-3 DIN EN 10028-7: 2008-02 X5CrNiMo17-13-3 AISI, ASTM A 240, ASME SA 240, SAE, UNS 316, S31600 1.4460 X3CrNiMoN27-5-2 EN 10088-1; -3; -5; EN 10250-4; EN 10297-2 X4CrNiMoN27 5 2 AISI, UNS, SAE, ASTM A 790 Duplex 329, S31260 1.4462 X2CrNiMoN22-5-3 EN 10028-7; EN 10088-1; -2; -3; -4; -5; EN Duplex 10216-5; SAF2205, S32205, S31803 EN 10217-7; EN 10222-5; EN 10250-4; EN 10263-5; EN 10272; EN 10296-2; EN 10297-2; EN 10312; 5512-3 AISI, UNS, ASTM A 240, ASME SA-182, 240, 789, 790, 815, SAE J 405 1.4501 X2CrNiMoCuWN25-7-4 DIN EN 10028-7: 2008-02 Super Duplex ASTM A 240, UNS S32760, Zeron 100 1.4507 X2CrNiMoCuN25-6-3 DIN EN 10028-7: 2008-02 Super Duplex ASTM A 240, UNS 255, S32520 1.4529 X1NiCRMoCuN25-20-7 DIN EN 10028-7: 2008-02 Super Duplex UNS, ASTM A 240 N08926 1.4534 X3CrNiMoAl13-8-2 EN 3357; EN 3358; EN 3359; EN 4347; EN 4461; EN S13800, XM 13 4462; EN 4463; EN 4464; EN 4465; EN 4466 UNS, ASTM A 276 1.4539 X1NiCrMoCu25-20-5 EN 10028-7; EN 10088-1; -2; -3; -4; -5; Superaustenite EN 10216-5; EN 10217-7; EN 10222-5; 904L, N08904 EN 10250-4; EN 10272; EN 10296-2; EN 10297-2; EN 10312; AISI, UNS, ASTM A 240 1.4541 X6CrNiTi18-10 DIN EN 10028-7: 2008-02 321, S32100 ASTM A 240, AISI, ASME SA-240, SAE, UNS 1.4542 X5CrNiCuNb16-4 DIN EN 10088-1; -2; -3; -4; -5; EN 10250-4; EN 3973 S17400, 630, F, 17-4PH AISI, UNS, AMS 5604, 5622, 5643, AS7474, ASME SA 564, ASME SA 705, ASTM A 1028, 564, 693, 705, 982, ASTM F 593, 594, 738, 836, 899, SAE J 467 1.4545 X5CrNiCu15-5 DIN EN 2821; EN 3361; EN 3479 S15500, XM-12 AISI, UNS, AMS 5659, 5826, 5862, ASME SA-705, ASTM A 564, 693, 705 1.4547 X1CrNiMoCuN20-18-7 DIN EN 10028-7: 2008-02 Superaustenite SMO, UNS, ASTM A 240, ASME SA-240 S31254, 254, Uranus B25 1.4562 X1NiCrMoCu32-28-7 SEW 400: 1997-02 Superaustenite UNS, ASTM A 314, 366, 462, 564, 581, 619, 622, N08031 625, 626, ASTM B 649, 924 1.4563 X1NiCrMoCu31-27-4 DIN EN 10028-7: 2008-02 Superaustenite UNS N08028 1.4565 X2CrNiMnMoN25-18-6-5 DIN EN 10088-1: 2005-09 Superaustenite UNS, ASTM A 1012, 182, 213, 240, 249, 269, S43565, F49, 403, WPS34565 276, 312, 358, 403, 409, 479, 480, 943, SAE J 405 1.4567 X3CrNiCu18-9-4 DIN EN 10269: 2006-07 X3CrNiCu18 9 AISI, UNS, ASTM A 493, ASTM F 593, 594, 836, 302 HQ, S30430 837, 879, 880, 899, 738, MIL-S-24149/6, MIL-S- 24149/3, SAE J 775 1.4568 X7CrNiAl17-7 DIN EN 10088-1; -2; -3; -4; -5; EN 10151; EN 10270-3 S32760, S17700, 631, 622, UNS, ASTM 631, AMS 5528, 5529, 5568, 5644, 17-7PH, X7CrNiAl17-7 5678, ASME SA-705, ASTM A 313, 564, 579, 693, 705, ASTM F 899, SAE J 217, 467 1.4571 X6CrNiMoTi17-12-2 EN 10028-7; EN 10088-1; -2; -3; -4; -5; 316Ti, S31635 EN 10216-5; EN 10217-7; EN 10222-5; EN 10250-4; EN 10263-5; EN 10272; EN 10296-2; EN 10297-2; EN 10312; 5512-3 AISI, UNS, ASTM A 240, SAE 1.4580 X6CrNiMoNb17-12-2 EN 10028-7; EN 10088-1; -2; -3; EN 10216-5; 316Cb, S31640 EN 10272; EN 10297-2; EN 10312 UNS, ASTM A 240, SAE 1.4591 X1CrNiMoCuN33-32-1 SEW 400: 1997-02 Superaustenite UNS, ASTM B 366, 462, 472, 564, 619, 622, 625, R20033 626, 649, 924 1.4652 X1CrNiMoCuN24-22-8 DIN EN 10088-1: 2005-09 Superaustenite UNS, ASTM A 1012, 240, 249, 269, 276, 312, 358, S32654 479, 480, 688, 988, SAE J 405 1.4662 X2CrNiMnMoCuN24-4-3-2 ASTM, UNS, S82441 alloy 2205; Duplex 1.4845 X8CrNi25-21 DIN EN 10088-1: 2005-09 Duplex AISI, UNS, AMS, ASME, ASTM A, SAE 310S, S31008 1.4847 X8CrNiAlTi20-20 AISI 334 1.4944 X5NiCrTiMoV26-15 SEW 390: 1991-11 Duplex AISI 660, UNS, AMS 5731, 5732, 5734, 5735, S66286 5736, 5737 1.4980 X6NiCrTiMoVB25-15-2/ EN 10088-1; EN 10269; EN 10302 X5NiCrTi26-15 UNS, AMS 5525, 5726, 5731, 5732, 5734, 5737, 660, 566286, A286 5804, 5805, 5810, 5853, 5858, 5895, AMS AS7235, AS7477, AS7478, AS7479, AS7481, AS7482, ASME SA-638, ASTM A 453, 638, ASTM F 2281, SAE J 467

(18) In embodiments of the present application, duplex or super duplex steels can be, for example, 1.4462, 1.4944, 1.4980 or SAF 2507. These are likewise listed in the tables above.

(19) In embodiments of the present application, nickel-base alloys can be, for example, the materials listed in the table below:

(20) TABLE-US-00003 Mat Chemical analysis in % by weight No. C Si Mn P S Cr Fe Mo W Co Ni Other 2.4600 0.01 0.1 3.0 0.030 0.015 1.0-3.0 1.0-3.0 27.0-32.0 3.0 3.0 65.0 Al 0.1-0.5; Cu 0 .5 2.4602 0.015 0.08 0.5 0.020 0.02 20.0-22.5 2.0-6.0 12.5-14.5 2.5-3.5 2.5 Rem. V 0.35 2.4610 0.015 0.08 1.0 0.025 0.015 11.0-18.0 .sup.3.2 14.0-17.0 2.0 Rem. Cu 0.5; Ti 0.75-1.3 2.4612 0.02 0.2 14.0-18.0 3.0 14.0-17.0 0.5 56 Ti 0.7; S 0.015; Mn 1.0 2.4616 0.02 0.2 1.0 2.0 26.0-30.0 1.0 64.5 Mn 2.0; S 0.05; V 0.4; Cu 0.5 2.4619 0.015 1.0 1.0 0.040 0.03 21.0-23.5 18.0-21.0 6.0-8.0 1.5 5.0 40 Cu 1.5-2.5; Nb 0.5 2.4663 0.05-0.15 1.00 1.00 0.015 20.0-24.0 3.0 8.0-10.0 10.0-15.0 44.50 Al 0.8-1.5; Ti 0.6; Cu 0.5; B 0.006 2.4665 0.05-0.15 1.0 1.0 0.020 0.015 20.5-23.0 17.0-20.0 8.0-10.0 0.2-1.0 0.5-2.5 Rem. Al 0.5; Cu 0.5; B 0.010 2.4668 0.02-0.08 0.35 0.35 0.015 0.015 17.0-21.0 10.0-12.0 2.8-3.3 1.0 50.0-55.0 Al 0.3-0.7; B 0.002-0.006; Nb + Ta 5; Cu 0.3; Ti 0.6-1.2 2.4675 0.01 0.08 0.50 0.025 0.01 22.0-24.0 3.0 15.0-17.0 2.0 Rem. Al 0.5; Cu 1.3-1.9 2.4694 0.1 0.5 1.0 0.01 14.0-17.0 5.0-9.0 70.0 Al 0.9-1.5; Cu 0.5; Nb 0.7-1.2; Ti 2.0-2.6 2.4733 0.05-0.15 0.25-0.75 0.3-1.0 0.03 0.015 20.0-24.0 3.0 1.0-3.0 13.0-15.0 5.0 Rem. Al 0.2-0.5; B 0.015; La 0.005-0.05 2.4816 0.05-0.1 0.5 1.0 0.02 0.015 14.0-17.0 6.0-10.0 .sup.72.0 Al 0.3; Cu 0.5; Ti 0.3 2.4819 0.01 0.08 1.0 0.025 0.01 14.5-16.5 4.0-7.0 15.0-17.0 3.0-4.5 2.5 Rem. V 0.35 2.4851 0.03-0.1 0.5 1.0 0.020 0.015 21.0-25.0 18.0 58.0-63.0 Al 1.0-1.7; Cu 0.5; Ti 0.5 2.4856 0.03-0.1 0.5 0.5 0.020 0.015 20.0-23.0 5.0 8.0-10.0 1.0 .sup.58.0 Al 0.4; Cu 0.5; Ti 0.4 2.4858 0.025 0.5 1.0 0.02 0.015 19.5-23.5 .sup.20.04 2.5-3.5 1.0 38.0-46.0 Al 0.2; Cu 1.5-3.0; Ti 0.6-1.2 2.4883 0.12 0.50 1.0 15.5-17.5 4.5-7.0 16.0-18.0 3.75-5.25 2.5 Rem.

(21) In embodiments of the present application, the cobalt-base alloys can be, for example, the alloy having the material number 2.4979 (Stellite 21 (corresponds to R30021 in accordance with UNS), Stellite 6b (R30016 in accordance with UNS) or Stellite 6 (R30106 in accordance with UNS)). Stellite is a brand name of Deloro Stellite Holdings Corporation.

(22) Other materials for use herein would be apparent to one of ordinary skill in the art.

(23) In yet another embodiment, to produce the brake band 13, carbon and/or nitrogen is made to diffuse into the brake band 13 at a temperature of less than 500 C., in particular of less than 300 C. If the carbon and/or nitrogen is made to diffuse at higher temperatures, carbides can form upon carbonitriding above approximately 650 C. and nitrides can form upon nitriding above approximately 500 C., these leading to embrittlement of the marginal layer 21. The diffusion is effected over a period of time of more than 48 hours, in particular of more than 96 hours. In particular, exclusively carbon is made to diffuse. The duration of the diffusion process is advantageously 6 to 7 days. The brake drum 12, with which the thus treated brake band 13 interacts, advantageously consists of a steel with a body-centered cubic or tetragonally distorted lattice structure. The surface of the brake drum 12 is advantageously not hardened or coated.

(24) In a further embodiment, alternatively, it can also be provided that the brake band 13 consists of a steel with a body-centered cubic or tetragonally distorted lattice structure and the brake drum 12 has a marginal layer 21 into which carbon and/or nitrogen have been made to diffuse. A brake drum 12 with a marginal layer 21 is shown schematically in FIG. 5. In this case, the brake drum 12 consists in particular of a stainless, austenitic steel, a duplex steel, a super duplex steel, a nickel-base alloy or a stellite alloy, in particular of one of the abovementioned alloys.

(25) The carbon content in the marginal layer 21 is approximately 1% by weight to approximately 7% by weight. The carbon and/or nitrogen is dissolved upon diffusion into interstitial lattice sites, and does not form any carbides or nitrides, respectively. The carbide proportion in the marginal layer 21 is therefore very small. The carbide proportion in a marginal layer 21 into which carbon has been made to diffuse is advantageously less than approximately 0.5% by weight. If nitrogen has been made to diffuse, the nitride proportion in the marginal layer 21 is advantageously very low, and is less than approximately 1% by weight, in particular less than approximately 0.5% by weight. The hardness of the marginal layer 21 is advantageously in the range of approximately 700 HV to approximately 1200 HV (Vickers hardness). The hardness of the marginal layer 21 is approximately 150% to approximately 600% of the hardness of the base body 20. Despite the high hardness of the marginal layer 21, the brake band 13 or the brake drum 12 with a marginal layer 21 does not undergo embrittlement.

(26) The marginal layer 21 has a thickness a of approximately 5 m to approximately 50 m, in particular of approximately 15 m to approximately 35 m. The thickness a can in this case be smaller than the material removed by wear during operation. It has been found that the shortening of the braking time is also achieved when the wear is greater than the thickness a of the marginal layer 21, into which carbon and/or nitrogen has been made to diffuse.

(27) The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description only. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible and/or would be apparent in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and that the claims encompass all embodiments of the invention, including the disclosed embodiments and their equivalents.