How to choose CBN inserts machining high hardness materials and the cutting parameters 

The machine range of Halnn superhard CBN inserts:

1. High hardness cast iron/cast iron machining,such as:rough machining and finish turning high chromium cast iron,white cast iron,Ni-hard cast iron, wear-resistant heat-resistant steel.

2. Machine high hardness after heat-treatment,such as:hard turning hardened bearing steel, Carburizing steel, tool steel and die steel after heat-treatment.

3. Other materials difficult to machining: superalloy,powder metallurgy,etc.

4. Ordinary gray cast iron, high grade of nodular cast iron.

Halnn superhard CBN inserts machine high hardness steel parts

When turning high hardness alloy steel,the workpiece has a high hardness,produce a large turning quantity heat,has alarge cutting force;causing the hard turning tools rapid wear,or the insert tip appear chipping.Halnn superhard suggest the cutting parameters with the experience of turning high hardness alloy steel.

The insert material and characteristic of Halnn superhard CBN inserts turning high hardness alloy steel

BN-S20 CBN inserts:rough machining and finish turning high hardness alloy steel with HRC45—HRC79.Such as:High hardness W18Cr4V, high-speed steel after heat treatment,Cr12MoV  tool steel,GCr15 ball bearing steel,9SiCr tool steel,20Cr,15CrMo,65Mn alloy steel material.It also can rough machining cast wear-resistance alloy ZGMn13,can restore high hardness alloy steel with big allowance rough machining,it also can stand strong interrupted cutting.It is one of the most popular superhard inserts.Following is the case of the BN-S20 CBN insert:

BN-H20 CBN inserts:It suit for finish turning high hardness alloy steel with HRC45-HRC68 with high-speed,such as:hard turning the 40CrMo,20CrMnTi gear after heat-treatment;BN-H20 use the Ceramic bond,has a higher thermal conductivity.It suit for high hardness alloy steel workpiece after heat-treatment,such as:high-speed finish turning hardened steel, nitride  steel, carburizing steel ,etc. 

Application case as following:

Cutting parameters of Halnn superhard tools machine high hardness alloy steel

Processing material	Cutting parameters and CBN inserts grade
	Linear speed Vc(m/min)	Cutting depth ap(mm)	Feed rate(mm/r)	CBN inserts grade
High hardness steels(hardness≥HRC45)	35-90(rough)	1-10	0.15-0.7	BN-S20
	60-120(finish)	≤1	0.05-0.35	BN-S20 or BN-H20
Superalloy (hardness≥HRC35)	200-500(rough)	1-10	0.2-1	BN-S20
	500-1500(finish)	≤1	0.05-0.3	BN-S20 or BN-H20

High hardness alloy steel include hardened steel,heat-resistant alloy,such as:alloy steel 3Cr2Mo,4Cr5mOv1Si which widely used for mold material,the hardness usually was between HRC45 to HRC68,some Nitride steel was above HRC65.

  

When machining high hardness alloy steel,we usually use BN-H20 CBN inserts when machining allowance was more than 0.5mm,if need one tool for rough machining and finish turning with big allowance,choose BN-S20 is better.

CBN inserts grade and instruction of Halnn superhard CBN inserts machine high hardness cast iron material

The hard point,pore,surface chill layer and sand in the cast iron workpiece did take some trouble during machining,quickening the inserts wear and damaged,especially machine cast iron mass in a assembly line,reduce the production efficiency;change the insert during finish machining big casting surface will affect the quality.As the application amount of the casting was large,reducing the machine cost or improving the efficiency will take us a objective economic benefits.So people request better insert for turning cast iron parts.Such as:mineral,building and metallurgy machinery parts made of white cast iron,high-chromium cast iron.Halnn superhard material company post BN-K1 and BN-S20 CBN inserts which can rough  machining high hardness cast iron in 2007. BN-S10,BN-S20,BN-K10,BN-K20 CBN inserts from Halnn superhard company achieve good result when machining high-chromium white cast iron and chilled cast iron;while the development of BN-S30 CBN inserts make a good result aiming at machining the wear resistant cast iron,this insert has a better wear resistance and higher hardness,suit for semi-finish and finish turning cast iron material workpiece.

Halnn superhard CBN inserts grade and cutting parameter:

Processing material	Cutting parameter and CBN insert grade
	Cutting linear speed Vc(m/min)	Cut depth ap(mm)	Feed rate(mm/r)	CBN insert grade
Hard cast iron (hardness:HRC35-68)	35-90(rough)	1-10	0.15-0.7	BN-K1
	60-120(finish)	≤1	0.05-0.35	BN-K1 or BN-K10
Grey cast iron/nodular cast iron	200-500(rough)	1-10	0.2-1	BN-S30
	500-1500(finish)	≤1	0.05-0.3	BN-K20 or BN-S30

The kind of Halnn superhard tools grade:

Grade	Classes	Application range
BN-K10	Soldering CBN insert	Suit for continuous finish turning gray cast iron and wear-resistant alloy cast iron materials, such as finish turning the brake drums, brake discs, flywheels, cylinder and other parts and high hardness cast iron materials.
BN-K20		High-speed finish turning gray cast iron, nodular cast iron, powder metallurgy finishing materials, and suitable for high speed precision boring.
BN-H10		Mild intermittent continuous or finish turning hard steel, such as the "turning instead of grinding" gears, bearings, etc.
BN-H20		Strong/semi-interrupted finish turning and high-speed finish turning, such as a variety of high-precision profiling shafts and gears, bearings, turning and small bore machining.
BN-K1	Solid CBN insert	Good impact resistance ,Rough machining high hardness cast iron in big margin such as:high-chromium alloy cast iron, high nickel chromium alloy, chilled cast iron, white cast iron; widely used in mining,metallurgical machinery,cement,electrical equipment wear spare parts.
BN-S20		Perfect balance between Impact resistance and abrasion resistance,can roughing,semi-finish turning and finish machining,suit for kinds of high hardness material,such as: High temperature alloys,heat-resistant steel, high hardness cast iron / steel, hardened steel, nitrided steel, carburizing steel.
BN-S30		High wear resistance and appropriate impact resistance,suit for high-speed finish turning gray cast iron,ductile iron, alloy cast iron and powder metallurgy, and suit for high-speed and efficiency boring, milling,

More information,http://www.halnntools.com/pro/,or contact with us halnntools@gmail.com;whatsapp:+8615036165377,skype:cbn_inserts_angels