Processing mill rolls is a difficult problem:
(1) The hardness of rolls get above HSD75. It is very hard to process
(2) Casting defects, such as sand inclusion, pore and hard particle, may occur due to operation, material and alloy composition during casting, which makes the processing more difficult.
(3) Some Mill rolls after repaired need to re-turning with high hardness. It is also very difficult to machine with uneven allowance and hardness.
Halnn superhard company, as a pioneer in the professional hardness materials cutting inserts field, studies the high hardness mill rolls, of which the sloid CBN inserts BN-K1 grade and BN-S20 grade already are recognized by a large number of users. Now, the inserts widely apply the mill rolls.
The advantage of halnn CBN inserts BN-K1 grade and BN-S20 grade:
(1) Halnn CBN inserts hardness is about HRC98.5 with strength wear-resistance.The abnormal phenomenon of severe abrasion will not occur in large allowance cutting of roll blank
(2) High durability: CBN inserts durability is several times and several times that of cemented carbide inserts and ceramic cutting tool.
(3) The cutting depth is several times than cemented carbide inserts which can improve the efficiency
(4) Strength impact.no collapse when the inserts process the mill rolls with the sand inclusion and pore
Halnn CBN inserts BN-K1 grade and BN-S20 grade process the mill rolls materials and cutting parameter
|
Roll Materials |
Working layer hardness
|
CBN
inserts
|
Recommend cutting parameter
|
|
Alloyed Cast Iron
|
HSD60-HSD80
|
BN-K1
|
Vc=40-60m/min,ap=2-10mm, Fr=0.5-1.5mm/r
Vc=60-90m/min,ap=1mm, Fr=0.5-1mm/r
|
|
Cast Semi-Steel
|
Vc=30-60m/min,ap=1-10mm, Fr=0.5-1.5mm/r
Vc=50-80m/min,ap=1mm, Fr=0.5-1mm/r
|
|
High Carbon Semi-Steel
|
Vc=35-50m/min,ap=3mm, Fr=0.5-1.5mm/r
|
|
Chilled Cast Iron
|
Vc=25-50m/min,ap=1-10mm, Fr=0.5-1.5mm/r
|
|
High Chrome Cast Steel
|
HRD85-92
|
BN-S20
|
Vc=20-45m/min,ap=4mm, Fr=0.5-1.5mm/r
|
|
Tungsten Carbide Rings
|
HRA88
|
BN-S30
|
Vc=10-15m/min,ap=1mm, Fr=0.3-0.7mm/r
|
|
Forging Cold-hardened Steel
|
HRC65
|
BN-S20
|
Vc=90m/min,ap=0.2-7mm
|
Application
1. Halnn CBN Inserts BN-S20 grade process high-speed steel rolls parameter
|
Workpiece
|
|
|
Materials
|
High speed steel
|
|
Workpiece Hardness
|
HSD90
|
|
Inserts Grade
|
BN-S20
|
|
Cutting Parameter
|
Fr=0.2mm/r Vc=50m/min
|
|
Cutting Method
|
Dry cutting
|
BN-S20 grade compared with cemented carbide cutter following:
Inserts materials |
Processing cycle
|
Each Insert life
|
Efficiency
|
|
Halnn BN-S20
|
2/h
|
25groove/piece
|
Improve 6 times
|
|
Camented carbide cutter
|
12/h
|
3groove/piece
|
/
|
2. Halnn CBN inserts BN-k1 grade processing the casting iron rolls parameter
|
Workpiece
|
|
|
Rolls Materials
|
Nickel-Chromium Alloy Cast Iron
|
|
Rolls Hardness
|
HSD80
|
|
Inserts Grade
|
BN-K1
|
|
Cutting Parameter
|
Ap=4mm r=1mm/r Vc=55m/min
|
|
Cutting Method
|
Dry Cutting
|
Halnn CBN inserts BN-K1 Compared with ceramic cutting tools following :
Processing the rolls inserts type : the user choose correspondence sizes types to process the casting iron rolls when they choose the CBN inserts BN-K1 grade. Those sizes types have RNMN200800，RNUN200800，RNMN150700，RNUN160800，RNUN150716，RNMN150716 and so on.
BN-S20 grade usually adopts SNMN120712，SNMN120412，SNMN120408，RNMN120400 to process the Forged steel roll.
Halnn superhard, as the pioneer of the localization of CBN inserts in China, is a well-known insets brand in the difficult-to-process material industry. It has mature cutting inserts and technical support in the iron and steel roll industry. Halnn superhard adopts service to select reasonable and efficient CBN inserts for customers.