Better performance on hard turning hardened steel with CBN insert 

For high speed machining ,manufacturers have 2 purposes:

1. Lower the cost through improving processing efficiency. Mainly used for finishing process, such as finish turning hardened steel gear ,bearing and mold tools industry.

2. Improve competitiveness through saving processing time and processing costs. Mainly used for roughing process, and choose the most suitable cutting tools materials.

In current times, there are carbide cutting tools, coated carbide insert, ceramic insert. When we choose cutting tools materials, we need to consider so many factors: insert structure, cutting parameters and the cut type, all will affect high speed machining process. So it is an important part of high speed machining technology.

When high speed machining, the work piece rotate with high speed, and it will produce large amount cutting heat. So it will be a key factor that how to take off these heat quickly. So when choose cutting tools materials, we not only need to choose the most suitable cutting tools materials, but also need to choose the suitable angle.

Cutting tools can be ranked depending on different factors.

As hardness: CBN insert＞Ceramic inserts＞Coated carbide tools＞Carbide cutting tools

As roughness：Carbide cutting tools＞Coated carbide tools＞Ceramic cutting tools＞CBN insert

As the previous technology, many manufactures will think that cbn insert has bad roughness and it will easily chipping. That is true, previous cbn insert only can be used for finishing and continuous process. But with the development of CBN insert ,Halnn researched new cbn insert materials-solid cbn insert which can be used for finishing and interrupt turning process through continuous research and practices. Solid CBN insert can be used for large allowance roughing and heavy interrupted turning high hardness materials with high speed.

Specific to current cutting tools materials, only cbn insert can performance well on high speed machining and also meet the requirement of “Green manufacturing”.

CBN Insert insert grade which can be used for high speed hard turning hardened steel :

BN-H21 and BN-10 CBN insert belongs to compound cbn insert, it has good hardness with the cutting edge, and also has a good performance with high speed finish turning process.

BN-H11 belongs to soldering cbn insert ,it is more flexible and has better machining accuracy when high speed machining.

BN-S20 and BN-S200 belongs to solid cbn insert, it has a good impact resistance and wear resistance for finishing and semi-finishing.

Solid CBN insert has already researched about 10 years ago, it is non-metal adhesive cbn insert. Especially BN-S20 Solid CBN insert which can be used for heavy interrupted turning hardened steel gear with hardness HRC60,get trust from many manufacturers.

More information on solid cbn insert,http://www.halnntools.com/pro/Solid_CBN_inserts/,Or contact with us halnntools@gmail.com ,skype:cbn_inserts_angels

Interrupted turning hardened steel cutting tools--- BN-H21 grade CBN inserts

As we all know, the hardness of hardened steel work piece is high, and difficult to machine, especially for interrupted turning condition, so the requirements on the cutting tools materials improve gradually.

In current times, the materials of machining hardened steel include carbide alloy, ceramic and CBN cutting tools, but because of high hardness of hardened steel, it only suit for CBN inserts .

Hardened steel work piece usually belongs to finish turning after heat-treatment,has small working allowance,and it will be more economical with soldering CBN inserts.But some hardened steel exist interrupted turning condition,such as turning key seating or oil bore on the surface of the work piece.In the process,CBN inserts are easily chipping,so many manufacturers are difficult to guarantee the precision and durability for interrupted turning hardened steel.

But as the manufacturing required product quality increase gradually,it not only require the work piece high precision,but also require product quality improved.Hardened steel,as one of the most common parts in manufacturing is the most important factor which cutting tools enterprise need value.

As a professional CBN inserts manufacturer, Halnn has good development in the following areas: high hardness cast iron/steel, high hardness steel after heat-treatment, cast iron, ect.

Now,as the increase of hardened steel interrupted cutting condition work piece, we researched BN-H21 grade CBN insert which can interrupt turning hardened steel work piece ,and already has good development in gear industry.

Application case as follows: 

1.Workpiece information:

Name: Gear

Hardness:HRC53~61

Other information:φ97.02 ,Depth30mm

Process: finish turning inner bore

Machining condition: semi-interrupted turning

Precision requirement:Ra1.6

Tolerance: +0.02

                    0

2.The cutting parameters of BN-H21 CBN insert interrupt turning gear inner bore

Inserts model:BN-H21 CCGW09T304-2S

Cutting Parameters:

N=500r/min;ap=0.08~0.12mm;Fr=0.08mm/r

Cutting Type:Dry Cutting

Working Efficiency:one cutting edge can machine 180~200piece work piece, and continue working about 3 hours. And guarantee the tolerance and precision requirement, and approval by customers .

More information:http://www.halnntools.com/pro/PCBN_inserts/DNMG.html

Machining gray cast iron CBN insert for CNC Lathe

Part 1  The characters of gray cast iron

(1) Poor strength; 

(2) Hardness: a range in tensile strength.

(3)Low notch sensitivity;

(4) Good reduction shock; 

(5) Good anti-friction properties. 

As its low cost, the production process is simple, so it also was widely used in auto parts, such as brakes, brake drums, flywheels. Some gray cast iron parts belong consumables, manufacturers will have large demands. Improving the processing efficiency and the costs become very important. So it is very important to choose the most suitable inserts material to machine the gray cast iron parts.

Part 2 How to choose inserts machining gray cast iron for CNC Lathe 

Currently, there are 3 kinds cutting tools can be used for machining gray cast iron for CNC Lathe:carbide insert, ceramic insert and CBN insert.

(1) Carbide insert: Carbide insert was sensitive to the linear velocity.when machining gray cast iron with high speed, the tools lifetime will be low, which will result a higher frequency for change the insert, and ultimately affect the
processing efficiency and increase the insert costs (choose carbide tools for small quantities machine the gray cast ironwaseconomical choice).

(2) Ceramic insert: the hardness of ceramic insert is higher than carbide insert, but as its brittle, white tissue easily chipping when meet hard spots,It is well for ceramic tools for finish machining or large allowance process.

(3) CBN insert : CBN insert has a higherhardness than carbide insert and ceramic insert, traditional CBN insert has bugs in brittleness. But Non-metallic binder BN-S30 CBN insert has a better toughness, higher hardness, better wear resistance, strong impact toughness, and can ensure part accuracy requirements while enabling high-speed cutting,can machine the parts when meet hard spots and white tissue without annealing directly.

The Cutting parameters of CBN insert machining gray cast iron 

The material of machined parts	CBN inserts cutting parameters and grade
	Cutting speed（m/min）	Cut depth (mm)	Feed rate （mm/r)	Insert grade
Gray cast iron	200-500(rough machining)	1-10	0.2-1	BN-S30
	500~1500（finish machining）	≤1	0.05-0.3	BN-S30,BN-K20 or BN-S300

The characteristic of BN-S30 grade CBN insert 

(1) High hardness;

(2) Better impact toughness and wear resistance

(3) High-speed cutting.

(4) Both roughing and finishing, Dry cutting and Wet Cutting                                                    

                             

BN-K20 and BN-S300 also can be used for finish machining gray cast iron.

BN-K20 CBN insert belongs to welded CBN insert, its advantage is more flexible,
more cutting edge number; excellent wear resistance; 

BN-S300 CBN insert belongs to the Solid CBN insert, advantages as follows: excellent sharp type, suit for gray cast iron work pieces finishing and semi-finishing.
                                                                                                 

Part 3 Application Case: Machining gray cast iron parts with BN-S30 CBN insert 

Rough and finish machining Cylindrical and end face on CNC lathe as the out diameter was different (300-419mm),the cutting time was different

One Japan carbide coated inserts: Depth of cut ap = 2.5mm (roughing), ap = 0.3mm (finishing), line speed 270-330m/min;
roughing and finishing spend respectively 5 minutes and 4.5 minutes.
Non-metallic binder BN-S30 CBN insert: Depth of cut ap = 2.5mm (roughing), ap=0.3mm (finishing),
linear speed 650-720m/min;spend separately 1.5 minutes and 75 seconds.   

Part 4 Summary

With the development of the technology ,manufacturers will required more on the insert lifetime and the product quality. They would like to improve the processing efficiency and obtain the excellent performance. And it also a big chance for insert manufacturers. Halnn is a professional manufacturer of cbn insert and always devote to researching new cbn insert materials to satisfy the customers’ requirements.And Halnn already become the most famous cbn insert brand in China .

Any question on cbn insert or hard materials machining,please contact with us halnntools@gmail.com.skype:cbn_inserts_angels

Rough machining Drum Brake used CBN insert

Drum brake is one of the main parts of the automotive, and belong to consumables, the surface roughness require about Ra1.6.We can choose a suitable insert to get better surface roughness while not affect the manufacture benefit. 

Part 1 Machining drum brake process

In current times, the brake drum brake main materials are gray cast iron. Gray cast iron has good shock absorption and wear resistant, and low noisy, it need simple process.

General process as follows:

Casting-Roughing-Semi-Finishing-Finishing-Drilling-Test.

(1)  Casting: when machining the drum brake, need control the charge mass, also the chemical composition of the molten iron, the pouring temperature, proper ingredients, avoiding casting defects, such as clip sand, porosity, white and so on.

(2)  Roughing: Manufacturers usually use CNC lathe machining the drum brake. Advantages(1.reduce the rejection rate of the work piece, 2.improve the processing efficiency. )

Roughing brake drums need about 0.5mm working allowance for subsequent semi-finishing and finishing guarantee finish requirements.

Part 2 The insert selection of rough machining drum brake

Process the drum brake need three steps,rough machining allowance within 3mm, and the brake drum need a high demand. In the process, it is important to ensure dimension, but improve processing efficiency,

Insert selection required:

1.High-speed cutting

2.Reducing processing time and improving processing efficiency.

First, manufacturers will use carbide insert, but its linear speed is low ,can not satisfy the requirements. So when meet machining gray cast iron with high speed, manufacturer will choose cbn insert which will not only improving the working efficiency, but also save the processing cost.

Especially Halnn BN-S30 and BN-K20 CBN insert, will be more effective for machining drum brake.

Part 3 Select the most suitable cbn insert for different process

(1) Roughing:When the working allowance within 3mm, select BN-S30 CBN insert, which not only has high hardness and high strength, but also has better wear-resistance and impact-resistance. Following show the figure on BN-S30 CBN insert machining brake drum:

Cutting parameters: ap=1-10mm,Fr=0.2-1mm/r,Vc = 200-800m/min. Processing effect: BN-S30 CBN insert lifetime with one cutting edge will be15 times than the coated carbide insert.

(2)Semi-finishing: Working allowance within0.5mm, BN-S30 CBN insert Cutting parameters: ap≤1mm, Fr = 0.05-0.3mm / r, Vc = 300-1500m / min.

(3)Finishing: within margin of 0.3mm, select BN-K20 CBN insert ,which will be more economical, can make sure the braking surface finish and mouth stop finish and dimension tolerances.

Following is the figure of BN-K20 CBN insert machining surface and mouth stopper .

Cutting parameters: ap≤1mm, Fr = 0.05-0.3mm / r, Vc = 300-1500m / min. Processing effect: BN-K20 CBN insert finish turning to ensure roughness Ra1.0, the single cutting edge lifetime is about 2 times than other PCBN insert.

Halnn is the most famous cbn insert brand in China, and always devote to researching new cbn insert to satisfy customers’ requirements.

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

CBN insert for hard turning hardened materials

PCBN inserts hardness (cubic boron nitride cutting tool) is generally HV3000 ~ 5000, HV hardness conversion HRC equivalent HRC95-100,for more than HRC50 high speed turning hardened workpiece, the most cost-effective in terms of reducing costs.

1.BN-H10 grade PCBN inserts:Continuous hard turning hardened steel,edge welded PCBN inserts,economic cutting speed Vc=120-230m/min; Fr = 0.1-0.25mm/r; figure as follows:

2.BN-H11 grades PCBN inserts: Continuous cutting,economic cutting speed Vc = 120-190m/min.Fr = 0.1-0.3mm/r,BN-H11 Welded CBN insert as follows:

3.BN-H20 grades PCBN inserts:Semi-interrupted turning PCBN inserts,economic cutting speed Vc=100-180m / min,Fr = 0.07-0.15mm/r,mosaic structure (with the BN-H11,as above).

4.BN-H21 grades PCBN inserts:Heavy interrupted turning inserts, weld edge structure (similar with BN-H10);good impact toughness,suitable for interrupted turning more than HRC55 hardened steel. inserts structure is similar with BN-H10.

5.BN-S20 grades:Solid CBN inserts:Halnn exclusive non-metallic binder CBN tools can be formulated roughing and interrupted machining hardened parts.Cutting Depth:up to 7.5mm,for repairing mold.Economic cutting speed Vc= 90~150m/min, Fr=0.1-0.45mm/r.

PCBN inserts commonly used fields:

1.    Finishing Gears and gear shaft after quenching, commonly used model number: BN-H10 CNGA120408, CNGA120404, BN-H20 WNGA080408, BN-H20 WNGA080404, BN-H10 VNGA160404, BN-H20 VNGA160408, BN-H20 DNGA150408, and so on.

2.    Finish turning Hardened steel rolls:RNGN120400 BN-S20, SNGN120408 BN-S20, SNGN120412 BN-S20, CNGN120408 BN-S20.

3. Hard turning Bearing industry:SNGN120712 BN-S20,RNGN090300BN-S200 and so on.

4. Other spare parts such as machining field after mold quenching.PCBN inserts hard turnin g hardened materials knowledge Brief:

Currently, PCBN inserts by Non-ferrous metal working fields, is the highest abrasion resistant tool material.PCBN inserts(CBN inserts) life is generally several times than carbide inserts and ceramic inserts.

With the development of research, PCBN inserts (cubic boron nitride inserts) to adapt to complex high hardness materials processing.BN-K10 can be processed of tungsten carbide more than HRC70. But PCBN inserts relate to the carbide material inserts. Aiming at hard and brittle weakness of CBN inserts. For example BN-S20 CBN inserts, it can not only interrupted turning hardened steel, may be a large margin resection hardened layer of the workpiece, but the premise is not at the expense of the cutting tool wear, and this is the biggest difference with PCBN cutting tool on the market.

More About Halnn products,please check http://www.halnntools.com/pro/,Or contact with us directly:halnntools@gmail.com

High Efficiency milling tools cubic boron nitride insert

The mold, especially precision molds usually required high performance, such as tool life time, wear resistance, toughness, fatigue resistance, corrosion resistance, etc,. So in the manufacturing process, heat-treatment process is often adopted to obtain excellent performance.

Simple processing process of mold: Forging (stamping) - machining - heat treating- assembly. For processing high-precision parts, the mold precision and dimension require more strict. But machining a high hardness after heat treating, and meeting all aspects performance of the mold, it have difficult processing problems, mold hardness after heat treatment is usually more than HRC50, some mold hardness will reach HRC60 or higher.

Rough milling mold usually use CBNinsert, and fine milling mold also can not use carbide cutting tools. Carbide cutting tools only used for processing the work piece with hardness above HRC45,the hardness of the molds already beyond the range of Carbide cutting tools that can be processed.

High hardness mold can only adopt milling CBN insert, CBN insert can meet all the conditions of milling mold. BN-S200non-metallic (ceramic) CBN insert can be used for fine milling the mold, and the biggest difference between traditional inserts(like ceramic insert ,carbide cutting tools) , CBN insert has strong impact toughness, high-speed cutting dies, no chipping with interrupted turning situations.

For example, BN-S200 CBN insertmachining Cr12MoV material mold, hardness HRC 65, machining processes are finish milling flat surface, cutting parameters: ap = 0.5mm; Fr = 0.12mm / r, Vc = 130m / min.

Processing effect:Compared with an European brands PCBN inserts: In the case of the same cutting parameters, tool life is higher than the European brand PCBN inserts,and cutting tool costs will reduce to 60%.

In addition to processing Mold, CBNinsert also can be used for machining the following materials with high efficiency :

1.High hardness cast iron/cast steel processing, such as: high-chrome cast iron, white cast iron, nickel hard cast iron etc. high hardness alloy cast iron, high manganese steel and other heat-resistant wear-resistant steel roughing and finishing;

2. High hardness work piece processing after heat treatment, such as: hardened bearing steel, hardened steel, nitrided steel, tool steel, mold steel hard turning after heat, can be interrupted cutting [insert toughness and wear resistance is excellent; processing high hardness steel parts between HRC45-HRC79]

3. Others difficult to cut materials categories: high-temperature alloys, powder metallurgy and tungsten carbide, nickel-based, cobalt-based alloy processing and thermal spray spary welding parts hard face processing [non-standard can be customized , sample processing]

4. Ordinary gray cast iron, pearlite ductile iron high-speed cutting [cutting tool life is 10-20 times of the alloy cutting tools]

More information on milling cbn insert BN-S200,you can check http://www.halnntools.com/pro/Solid_CBN_inserts/, Or contact with us halnntools@gmail.com ,skype :cbn_inserts_angels

Halnn BN-S20 Solid CBN insert rough machining mill rolls

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Halnn CBN insert finishing turning Gear end surface and interrupted turn...

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Choose suitable cutting tools materials and cutting parameters for CNC Lathe

Establish machining process is similar to the ordinary lathes machining process when using CNC lathe to machining,the CNC lathe is clamp one time to complete all the turning process with continuous automatic machining,so we need pay more attention to choose the suitable insert and cutting parameters.

 Part 1 The principle of choosing cutting tools for CNC lathe

1.There are lots of different requirements on CNC lathe insert than ordinary lathe insert,such as:

a.High rigidity(especially cbn insert for rough machining),high precision,anti-vibration and little thermal deformation;

b.Have a good inter operability,easily change;

c.Has a long lifetime,a stable and cutting performance;

d.It is convenient to adjust the insert size,for saving the time of change cutting tools;

e.Should chip breaking for excluding the chip;

f.Serialization,standard,good for program and manage tools.

2.Choose the suitable insert material:

a.High-speed steel insert;

b.Carbide insert;

c.Diamond insert;

d.Other material insert,such as CBN(Cubic Boron Nitride)insert,ceramic insert,etc.

Classification by the cutting technology:the hard turning inserts:cylindrical,inner bore,screw thread,cutting tools,etc.

 Part 2 The step to choose the CNC lathe cutting tools

1.Confirm the CNC cutting tools angle first:

Choose the insert angle according to the work piece shape and machining technology,this step is same as the ordinary cutting tools choosing step.For example,the CNC turning tools for cylindrical,just as following method:

2.Match the right CNC insert according to the chosen turning tools type:

(1)Choose the insert material according to the work piece material first,you need pay more attention on :as many insert material is universal,such as high-speed steel insert,carbide insert and coated carbide insert are all be well for machining the 45 steel,you need to choose the insert material according to the production rate.

For example CBN(Cubic Boron Nitride)insert is usually used for turning the HT250 material;BN-S30 grade CBN insert efficiency is 2-5 times than carbide insert when machining the gray casting work piece.

With the development of  insert technology,high performance insert material appeared,it can improve both machining efficiency and machining quality.

For example,BN-S30 CBN(Cubic Boron Nitride)insert from Halnn superhard,its lifetime is 10 times more than Mitsubishi UC5115 grade coated carbide insert when rough machining Cast iron HT250;and the gray cast iron roughness can reach Ra1.6 when finish machining.

(2)Choose the insert tip arc angle and groove according to the process technology require.You can reference catalogue to get the details.

Part 3 The three cutting key points for choosing insert

Three key points of cutting parameter:Cutting depth,feed rate and linear speed.The cut depth was usually confirmed according to the machining margin,the roughing feed rate according to the lathe machine power,finishing feed rate based on surface roughness;the linear speed was confirmed according to the insert material and rotate speed of lathe machining main shaft.

Increase cutting depth is a method which was worth to considered to improve the machining efficiency.When the cutting depth is 10 times than feed rate,the insert durability almost wont change if increase the cut depth continuous.While Change the cutting speed,the insert durability will also change with two times;the insert durability will also change with the feed rate change.So increase the cutting depth can not only realize the a high production rate,but also wont increase the insert cost.

Detail Application case you can reference this link :Three cutting elements and machining efficiency of cutting tools,Or contact with us halnntools@gmail.com,skype: cbn_inserts_angels.