As an important tool for rolling metal billets into products, the cost of the mill rolls is about 5%-15% of the cost of rolling steel production,which is directly related to the

production efficiency, product quality and production cost of steel production enterprises.

However, the following problems often occur in machining mill rolls: 

(1) Hardness of mill rolls is above HSD75,its difficult to machining;

(2) Casting, sanding, venting, hard spots, etc. may occur due to problems such as operation, material, and alloy composition. Defects make the processing process difficult;
 

(3) The partially repaired rolls also need to be turned and have high hardness. Unevenness and uneven hardness are also difficult to process.

When traditional carbide tools are used to process such mill rolls, there are often problems such as severe wear at the tool, which affects production efficiency and production cost.

At this time, the use of Halnnsolid CBN tool can not only suitable for roughing & finishing mill rolls, the metal removal rate is high, the tool durability is high, reducing the frequency of

tool change and improving production efficiency.

The following is a detailed introduction to the CBN tool grade and case parameters of Halnn CBN tool machining mill rolls.

 
1. Halnn CBN tool grade for machining mill rolls

Halnn CBN tool grade for machining mill rolls
CBN grade	Machining process	Processing conditions	advantage	Tool pattern
BN-K1	Roughing and finishing	Heavy interrupt cutting	Excellent in fracture resistance and high temperature fracture resistance.
BN-S20	Roughing and finishing	Heavy interrupt cutting	Excellent thermal shock resistance and wear resistance.

2. Cutting parameters of Halnn BN-K1 &BN-S20 grade CBN tools machining Mill Rolls

Recommended cutting parameters
Workpiece materials	Cutting speed Vc(m/min)	Cutting depth Ap(mm)	Feed rate Fr(mm/r)	CBN tool grade
High hardness cast iron roll	35-120(roughing)	1-10	0.15-0.7	BN-K1
	60-180(finishing)	≤1	0.05-0.35
High hardness steel roll	50-150(finishing)	1-10	0.15-0.7	BN-S20
	60-250(finishing)	≤1	0.05-0.35

3. Halnn BN-K1 grade CBN tool machining mill rolls

Halnn BN-K1 grade CBN tool machining mill rolls
	Workpiece materials: high ni-cr cast iron Workpiece hardness：HSD80 Tool type：BN-K1 RNMN200800 Cutting parameters：Vc=55m/min，Fr=1mm/r，ap=4mm Processing: dry cutting
Tool materials	Feed rate   Fr (mm/r)	Single edge life	Final failure
Halnn BN-K1 grade CBN tool	1mm/r	3pcs/edge	Normal wear
Ceramic cutting tool	0.5mm/r	0.5pcs/edge	Collapse damage

 

Halnn BN-S20 grade CBN tools machining mill rolls
	Workpiece materials：High speed steel Workpiece hardness：HSD90 Tool type：BN-S20 RCMX120700 Cutting parameters：Vc=50m/min，Fr=0.2mm/r Processing: dry cutting
Tool materials	Processing beat	Single edge life	Efficiency
Halnn BN-S20 grade CBN tool	2 hour	25 slot/edge	6 times
Traditional Carbide tool	12 hour	3 slot/edge	------