TECHNICAL GUIDE MILLING AND TURNING - Bisalloy Steels · 04 | BISALLOY® is a registered trade mark of Bisalloy Steels Group Limited, ABN 22 098 674 545 82 AVOID VIBRATIONS Indexable

TECHNICAL GUIDE

MILLING AND TURNING

02 | BISALLOY® is a registered trade mark of Bisalloy Steels Group Limited, ABN 22 098 674 545

BISALLOY® has recently introduced a new product nomenclature. The following table details the grade equivalents.

Note: Only the designation has changed – not the product

INTRODUCING OUR NEW PRODUCT NOMENCLATURE

Previous Name New Name

BISPLATE® 60 BISALLOY® Structural 60 steel




BISPLATE® 80PV BISALLOY® Structural 80 Pressure Vessel steel

BISPLATE® 320 BISALLOY® Wear 320 steel





BISPLATE® HIA - Class 2 BISALLOY® Armour RHA300 steel

BISPLATE® HIA - Class 1 BISALLOY® Armour RHA360 steel

BISPLATE® HTA BISALLOY® Armour HTA400 steel

BISPLATE® UHT BISALLOY® Armour UHT440 steel

BISPLATE® HHA BISALLOY® Armour HHA500 steel

BISPLATE® UHH BISALLOY® Armour UHH600 steel

2017 TECHNICAL GUIDE - TURNING AND MILLING RECOMMENDATIONS | 03

MILLING AND TURNING BISALLOY® STEEL

Milling and Turning recommendations

MILLING

Milling operations can be performed satisfactorily on all BISALLOY® steel grades; utilisation of indexable carbide cutters is recommended.

In many situations, the milling operation entails the dressing of a flame cut edge, and then subsequent bulk milling of material to the desired surface finish and dimensional tolerance.

Care must be taken to make a first cut sufficiently deep to remove the heat affected zone of the flame cut edge. Cutters must be sufficiently robust to take this heavy loading. In such circumstances it is desirable that, due to the high hardness

MILLING

adjacent to the flame cut surfaces, cutter speeds and feed rates for initial milling should be reduced to 40 - 50% of the speed normally used when milling plain carbon steel. The importance of adequate preheating prior to flame cutting and slow cooling after cutting to minimise edge hardening is again emphasised. Speed and feed rates may be increased somewhat for subsequent bulk milling to 50 - 75% of the settings used for plain carbon steel.

MILLING RECOMMENDATIONS

Notes: These recommendations are given as a guide only, and are based on stable working conditions. It is suggested a 45 deg. Approach angle or a round insert facemill be used. For quick metal removal a very successful cutting method is the use of FF Fast Feed Milling Cutters by ISCAR. Feed rates are dependent on geometry selected.

Table 1:

BISALLOY® steel GRADE ISCAR INSERT GRADE SURFACE SPEED Vc m/min FEED/TOOTH Fz

BISALLOY® Structural 60 steel IC830 200 - 300 0.15 - 0.25



BISALLOY® Structural 100 steel / BISALLOY® Wear 320 steel

IC830 120- 140 0.15 - 0.25

BISALLOY® Wear 400 steel IC808 80 - 120 0.15 - 0.25




04 | BISALLOY® is a registered trade mark of Bisalloy Steels Group Limited, ABN 22 098 674 545

82

AVOID VIBRATIONS

Indexable inserts are sensitive to vibrations. These can be avoided or reduced by observing the following.

When turning or milling gas cut edges the cutting depth should be at least 2 mm to cope with the hardness and unevenness of the edge.

Figure 1: Figure 2:

Showing the direction of milling. Showing the eccentricity milling cutter. OTHER MILLING REQUIREMENTS

• Firm clamping of the workpiece• Use cutters with the smallest possible gap between the teeth• Machine stability permitting, unidirectional milling is preferable, see figure 1• If a large cutter is used for the milling of small areas, place the milling cutter eccentrically to get as many teeth as possible

operating, see figure 2• Avoid, if possible, the use of a universal cutterhead which generally causes weakening of the power transmission and the

tool holder

Undirectional milling

Opposed milling

Normal width

Small width

82

AVOID VIBRATIONS



Figure 1: Figure 2:

Showing the direction of milling. Showing the eccentricity milling cutter. OTHER MILLING REQUIREMENTS

• Firm clamping of the workpiece• Use cutters with the smallest possible gap between the teeth• Machine stability permitting, unidirectional milling is preferable, see figure 1• If a large cutter is used for the milling of small areas, place the milling cutter eccentrically to get as many teeth as possible

operating, see figure 2• Avoid, if possible, the use of a universal cutterhead which generally causes weakening of the power transmission and the

tool holder


Opposed milling

Normal width

Small width


Opposed milling

Normal width

AVOID VIBRATIONS



OTHER MILLING REQUIREMENTS

• Firm clamping of the workpiece.

• Use cutters with the smallest possible gap between the teeth.

• Machine stability permitting, unidirectional milling is preferable, see figure 1.

• If a large cutter is used for the milling of small areas, place the milling cutter eccentrically to get as many teeth as possible operating, see figure 2.

• Avoid, if possible, the use of a universal cutterhead which generally causes weakening of the power transmission and the tool holder.

Figure 1:

Showing the direction of milling

Figure 2:

Showing the eccentricity milling cutter

Small width

TURNING AND MILLING BISALLOY® STEEL

Milling and Turning recommendations continued...

2017 TECHNICAL GUIDE - TURNING AND MILLING RECOMMENDATIONS | 05

OTHER TURNING REQUIREMENTS

• Firm clamping of the workpiece.

• Avoid long overhangs for both workpiece and tool holder.

• Use correct tip radius: too large a tip radius, combined with insufficient clamping, causes vibrations.

• Small setting angles also can cause vibrations.

Bisalloy Steels wish to thank ISCAR Australia Pty Ltd for information pertaining to milling and turning contained in this publication.

TURNING

All BISALLOY® steel grades, including those with hardness in excess of 400 HB can be turned satisfactorily with carbide tooling, provided spindle speeds and feed rates are reduced from those normally employed when carrying out similar machining operations on plain carbon steel. Reductions of 50 - 70% in spindle speed and up to 50% in feed rate may be necessary, depending on the hardness of the component being machined. High speed tools are not recommended.

As an example, the following settings have been found to give satisfactory results when turning cylindrical workpieces of 25 mm diameter from the various BISALLOY® grades. With increases in stock diameter, spindle speeds will obviously need to be decreased.

Notes: These recommendations are given as a guide only and are based on stable working conditions. The geometry of the inserts used will be dependent on the operation. Insert Geometry, Nose Radius and Chipbreaker will determine the depth of cut and feed rate.

Table 2:

BISALLOY® steel GRADE

ISCAR INSERT GRADESURFACE SPEED Vc

m/min

BISALLOY® Structural 60 steel

IC8150 180 - 340


IC8150 180 - 330


IC8150 180 - 320

BISALLOY® Structural 100 steel /

BISALLOY® Wear 320 steel

IC8150/IC807 120 - 220


IC8150/IC807 100 - 150


IC807 60 - 120


IC807 40 - 80


IC807 30 - 60

TURNING RECOMMENDATIONS

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02 4272 0444www.bisalloy.com.au

© Bisalloy Steels Group Limited 2017. BISALLOY® is a registered trade mark of Bisalloy Steels Group Limited, ABN 22 098 674 545

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TECHNICAL GUIDE MILLING AND TURNING - Bisalloy Steels · 04 | BISALLOY® is a registered trade mark of Bisalloy Steels Group Limited, ABN 22 098 674 545 82 AVOID VIBRATIONS Indexable