ULTRA CLEAN HIGH STRENGTH STEEL FOR POWER TRAIN APPLICATIONS

Transcription

1 ULTRA CLEAN HIGH STRENGTH STEEL FOR POWER TRAIN APPLICATIONS

2 FOR HIGHLY DURABLE COMPONENTS BÖHLER VMR is an ultra high steel for motorsport and advanced engineering applications. Excellent mechanical properties are combined with the ultimate level of cleanliness in a heat treatable steel. Application Highly fatigue loaded components in motorsport and advanced engineering industries, e.g. cam shafts, gudgeon pins, con rods, crankshafts, bolts and drive shafts. Advantages Double vacuum melted production route High fatique Exceptional cleanliness Excellent mechanical properties Properties Super-high to avoid plastic deformation and ensure an optimized fatigue High stiffness: relation between density and High tempering temperatures allow for a comprehensive range of surface treatments. Chemical composition C Si Mn Cr Mo V Ni (average %) 300M M Si

3 Heat treatment sequence HEAT TREATMENT RECOMMENDATIONS Hardening Supplied condition Annealed, 205 HB max. Heat treatment Stress relieving 650 bis 700 C (1202 to 1292 F) After through-heating, soak for 1 to 2 hours in a neutral atmosphere. Cool slowly in furnace. Hardening C ( F)/ depending on the required properties oil, salt bath 500 bis 550 C (932 to 1022 F), polymere, air, vacuum furnace with gas quenching Holding time after through-heating: 15 to 30 minutes Tempering Slowly heat to tempering temperature immediately after hardening. Time in furnace: 1 hour for every 20 mm of workpiece thickness but at least 2 hours. Cool in air. We recommend that the steel should be tempered at least 3 times. 1 st tempering approx. 30 C (86 F) above maximum secondary hardness. 2 nd tempering to desired working hardness. The tempering chart shows average tempered hardness values. 3 rd for stress relieving at a temperature 30 to 50 C (86 to 122 F) below highest tempering temperature. Annealed microstructure Temperature in C ( F) Hardening temperature: 1050 C (1922 F) 1070 C (1958 F) Tempering chart Stress relief 2 nd preheat stage 1 st preheat stage 2 nd tempering Saltbath working hardness Cooling 1 st tempering in furnace Time Cleaning Hardness test Vacuum heat treatment Oil Air cooling Hardness test 3 rd tempering for stress relief BÖHLER VMR 0 10 μm Hardness (HRC) Process temperature, surface treatment Tempering temperature 40 0 (32) 300 (572) 350 (662) 400 (752) 450 (842) 500 (932) 550 (1022) 600 (1112) 650 (1202) Tempering temperature 3 x 1 h [ C ( F)] 4 5

4 MATERIALS OF THE HIGHEST PURITY Vacuum Arc Furnace (VAR) The motorsport industry is relentless in it s pursuit of excellence. We melt our materials with the same perfectionism. BOHLER VMR is double vacuum melted to produce a material with exceptionally high micro cleanliness for use in the most demanding applications. 1 Remelting of consumable electrodes under vacuum, operating pressure 10-3 mbar Two melting stations offset by 90 Microprocessor-controlled remelting process P 10-6 bar 3 2 Advantages Minimum gas contents Reduction of trace elements such as Pb, Bi, Te Minimum microsegregations in the ingot centre Low susceptibility to the formation of freckles (segregations) Highly precise chemical analysis DC Stinger 2 Furnace Head 3 Stub 4 Electrode 5 Static Mold 6 Liquid Metal 7 Ingot DC Power Supply 6 7

5 PHYSICAL PROPERTIES Physical properties Hardness Elastic modulus Density 300M 55 HRC MPa 7,87 kg/dm 3 300M Si 55 HRC MPa 7,66 kg/dm 3 Thermal conductivity at 100 C 200 C 300 C 400 C 500 C 31,5 32,3 32,6 32,5 31,9 in W/(m.K) 210 F 390 F 570 F 750 F 930 F Btu / in/ft 2 h F Thermal expansion between 20 C (68 F) and... C ( F) 100 C 200 C 300 C 400 C 500 C 600 C 700 C 11,1 11,5 11,9 12,3 12,8 13,2 13, m/(m.k) 210 F 390 F 570 F 750 F 930 F 1110 F 1290 F in/in F 55 HRC MPa 7,81 kg/dm 3 Average value Ultimate tensile Yield Fatigue 300M 2000 MPa 1680 MPa 590 MPa 300M Si 2150 MPa 1730 MPa 680 MPa 2250 MPa 1800 MPa 780 MPa Comparison of ultimate tensile and yield Comparison of fatigue MPa MPa Ultimate tensile Yield Ultimate tensile Yield Ultimate tensile Yield M 300M Si 300M 300M Si Rotating bending test on notched samples: R = 1, K t = 2 (2 x 10 6 cycles) 8 9

6 MACHINING RECOMMENDATIONS DELIVERY CONDITION As you like it! A wide variety of possibilities when it comes to the machining and finishing of long products allows us to dedicate ourselves to customer requirements individually and rapidly in the BÖHLER service tradition. Rolled bar steel is put through a heat treatment and machined, finished and tested according to customer specifications. BÖHLER endeavours to fulfil every customer request regarding surface treatment: bar steel, round-peeled, peeled and polished, continuously ground or turned; machined at both ends upon request; bar steel, flat milled and cut to large-scale flat dimensions and ingots. In the BÖHLER tolerance range you require. For example: IBO ECOMAX bar steel, peeled ECOBLANK bright steel, peeled and polished, decarb-free ECOFINISH bright steel, band ground BRIGHT STEEL ground and polished Condition: annealed. Figures given are guidelines only. Turning with sintered carbide Depth of cut mm (inches) (.02.04) 1 4 (.04.16) 4 8 (.16.31) over 8 (over.31) Feed mm / rev. (inches/rev.) ( ) ( ) ( ) ( ) BOEHLERIT grade SB10, SB20 SB10, SB20, EB10 SB30, EB20 SB30, SB40 ISO grade P10, P20 P10, P20, M10 P30, M20 P30, P40 Indexable inserts Tool life: 15 min ( ) ( ) ( ) ( ) Brazed carbide tools Tool life: 30 min ( ) ( ) ( ) ( ) Coated indexable inserts Tool life: 15 min. BOEHLERIT ROYAL 121 up to 300 (980) up to 270 (885) up to 195 (640) up to 125 (410) BOEHLERIT ROYAL 131 up to 240 (790) up to 175 (575) up to 135 (445) up to 70 (230) Tool angles for brazed carbide tools Clearance angle Rake angle Inclination angle Turning with high speed steel Depth of cut mm (inches) 0.5 (.02) 3 (.12) 6 (.24) 10 (.40) over 10 (.40) Feed mm / rev. (inches/rev.) 0.1 (.004) 0.5 (.020) 1.0 (.040) 1.5 (.060) over 1.5 (.060) HSS-grade BÖHLER/DIN S700 / DIN S Tool life: 60 min ( ) (100 70) (70 60) (60 40) 16 8 (50 25) Rake angle Clearance angle Inclination angle Milling with inserted tooth cutter Feed mm/tooth (inches/tooth) up to 0.2 (.008) ( ) BOEHLERIT SBF / ISO P ( ) ( ) BOEHLERIT SB40 / ISO P ( ) ( ) BOEHLERIT ROYAL 131 / ISO P ( ) Drilling with inserted carbide Drill diameter mm (inches) 3 8 (.12.31) 8 20 (.31.80) ( ) Feed mm / rev. (inches/rev.) ( ) ( ) ( ) BOEHLERIT/ISO grade HB10 / K10 HB10 / K10 HB10 / K ( ) ( ) ( ) Point angle Clearance angle

7 SPECIAL STEEL FOR THE WORLD S TOP PERFORMERS Your partner: BÖHLER Edelstahl GmbH & Co KG Mariazeller Straße 25 A-8605 Kapfenberg/Austria Phone: Fax: info@bohler-edelstahl.at Printed on chlorine-free bleached paper having no pollution effects. The data contained in this brochure is merely for general information and therefore shall not be binding on the company. We may be bound only through a contract explicitly stipulating such data as binding. Measurement data are laboratory values and can deviate from practical analyses. The manufacture of our products does not involve the use of substances detrimental to health or to the ozone layer. DE CD