Техническая информация Sumitomo - страница 19

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Hardened Steel Machining with SUMIBORON

  • Application Map of the Various Tool Materials
  • Work Materials and their Cutting Speed Recommendations

300 Heavy

Coated 200 carbide cermet SUMIBORON Light 100

Ceramic Carburised or Induction Hardened Material Bearing Steel Die Steel

40 45 50 55 60 65

Hardness of Work Material (HRC) Prone to notch wear Wear fairly large Wear large

  • Influence of Coolant on Tool Life
  • Relation Between Work Material Hardness and Cutting Force
  • Continuous Cutting
  • Interrupted Cutting

Feed force SKD11–4U Slotting

0.3 Cutting speed v =100m/min Principal force

c 150

DRY D.O.C a =0.2mm Feed force

Oil-base coolant p

0.25 Feed rate f =0.1mm/rev Back force

Water soluble emulsion Water soluble

0.2 Heavy Back

Interrupted 100 force

Cutting 0.15 100 Principal force 0.1 ☆ In continuous cutting of bearing steel, 50

0.05 there is not much difference in dry or wet cut. 50

Work : SK 3

0 DRY Wet Conditions : C/speed vc =120m/min.

20 40 60 80 100 120 140 0 D.O.C a =0.2mm

Cutting Time (min) p

0 10 30 50 70 Feed rate f =0.1mm/rev

Hardness of Work Material (HRC) For continuous cutting, the influence of Work: SUJ2(58 to 62HRC) Condition: TPGN160304 coolant on tool life is minimal. However, Back force increases substantially for harder work materials. v =100m/min a =0.15mm f =0.1mm/rev Continuous cutting for interrupted cutting, coolant will shorten c p the tool life because of thermal cracking.

  • Relation Between Flank Wear and Cutting Force
  • Influence of Work Material Hardness on Cutting Force and Accuracy

300 Cutting Speed : v =120m/min SCM430 c

Hard Soft Hard Depth of Cut : a =0.5mm

65HRC Condition: C/speed v =80m/min p

c zone zone zone Feed rate : f = 0.3mm/rev Dry

200 D.O.C ap=0.15mm

Feed rate f =0.1mm/rev Work: S38C S55C

100 24HRC 90

70 50 45(HS) 0 30 100 400

For hardened steel machining,300External dimension at the
0back force increases substantially106Nsoft zone is smaller due to

200

100 due to the expansion of flank wear. lower cutting forces.

0

0 -10 13μm

0.05 0.10 Flank Wear Width V (mm) -20 B

  • Relation Between Cutting Speed and Surface Roughness
  • Improvement of Surface Roughness by Altering the Feed Rate

Constant Feed Rate Variable Feed Rate Work: SCM420H BN250 V=120 Previous edge position

BN250 V=150 58 to 62HRC N

BN250 V=180 Holder: MTXNR2525 0.3 Insert: NU–TNMA160408 0.2 Conditions: v = 120, 150, 180 m/min c f = 0.045mm/rev

a = 0.15mm Stationary Notch Location Shifting Notch Location

0.1 p Wet

0

0 40 80 120 160

Machining Output (pcs.) At high cutting speeds, surface roughness is more stable.

☆ Varying the feed rate spreads the notch location over a larger area. → Surface finish improves and notch wear decreases. N27