Halnn Cubic boron nitride(CBN) insert used for hard turning Gear after heat processing/heat treatment

With the development of the automotive industry,It required higher on quality and performance for the automotive gears and other parts,heat treatment processing was widely used in the automotive and other industries.

Part One The heat treatment processing technology of the auto gear

(1) Normalizing
1)Definition of normalizing:The metal heat treatment process technology of the work piece will be heated to Ac3 (Ac refers to the entire heating free ferrite into austenite finish temperature, generally between from 727℃ to 912 ℃) or Acm (Acm is the actual heating hypereutectoid fully austenitic steel critical temperature line) more than 30~50℃,holding this temperature for a while,then remove from the oven to the air,spray water or fog,or cooling. 
2) Purposes of normalizing :
3) Main application of normalizing:

①  low-carbon steel; 

② carbon steel; 

③ ftool steel,bearing steel,carburizing steel; 

④ steel castings; 

⑤ large forgings;  
⑥ ductile iron.
(2) quenching (quenching and tempering)
1) quenching definition:The composite heat treatment processing technology of the steel materials quenching and tempering (500°-650°). hardened and tempered steel is the steel needed quenching. It generally was the carbon-carbon structural steel and alloy steel.
2) quenched applications:
(3) Carburizing
1) Definition:The process to make the carbon atoms into the steel surface layer.
2) Purposes:Getting a high surface hardness, high wear resistance and fatigue strength,  make the work piece can stand shock loads, in order to extend the life of the part.
3) Applications:the material of the carburizing parts is generally used in low-carbon steel or carbon steel (carbon content less than 0.25%).Carburizing process is widely used in aircraft,automobiles and tractors and other mechanical 
parts,such as automotive gear,cam shaft and so on.

Part Two The material selection and processing of automobile gear

1) Material for automotive gears: automotive transmission gears, drive axle pinion gear, differential gear drive and others often used 20CrMoTi,20CrMo;automotive crankshaft timing gear often used 35,40,45 or 40Cr;car starter gear often using 15Cr, 20Cr,20CrMo,15CrMnM,20CrMnTi .
2) Process for Automobile Gears: processing of transmission gear 20CrMnTi material:cutting-Forged-normalizing -machining -carburizing - quenching and tempering- 
3) The hardness and Performance after heat treatment of the Automotive gear 

Part Three how to choose the inserts for machining the Automotive Gear after heat treatment

The automotive gear After heat treatment need finishing.So it is important for choosing the inserts for this. Halnn CBN insert is a good choice,it is efficiency and save processing costs.

Currently,the inserts material for processing automotive gear after heat treatment has carbide tools, ceramic cutting tools and cubic boron nitride cutting tools (CBN tool).Select the appropriate tool material finishing automobile gear according to the hardness after heat treatment of automobile gear.

(1)Processing the hardness under HRC45 of the automotive gear after heat treatment:It is better to choose carbide inserts.


(2)Processing the hardness over HRC45 of the automotive gear after heat treatment:You can also choose a ceramic cutting tools and cubic boron nitride cut-ting tools (CBN tools)If the hardness was between 45HRC and 50HRC, ceramic tool is a better choice.Forhardness above HRC50 after heat treatment and the presence of intermittent automotive 

Part Four The parameters of Halnn CBN inserts for finishing process the auto gears

Halnn superhard inserts company research three kinds of CBN inserts for finishing automotive gear: BN-H10,BN-H20 and BN-S20 CBN insert.

The condition of automobile gears processing and working	Insert Grade	Suitable Cutting Parameters
		ap(mm)	Fr(mm/r)	Vc(m/min)
Continuous turning	BN-H10	0.2	0.1	180
Semi-interrupted turning	BN-H20	0.25	0.1	120
Heavy interrupted turning	BN-S20	2.5	0.12	90

In order to getting higher hardness,better wear resistance and fatigue resistance are needed when machining the auto gear parts.People usually use heat treatment to raise those performance.The gears parts which needed heat treatment include:high speed gear of the ehicle drive axle,transmission gears,engines gear and others.The Heat Treatment technology of Automotive gear usually use normalizing,quenching(quenching and tempering),carburizing and other technology.Now we will introduce the purpose and scope of application automobile gear heat treatment process in brief as follows:

①remove the internal stress of the material; 

② increase the hardness of the material.

①  low-carbon steel; 

② carbon steel; 

③ ftool steel,bearing steel,carburizing steel; 

④ steel castings; 

⑤ large forgings; 

The work piece after quenching is not only has a high strength but also has a good ductility and toughness,good abrasion resistance,anti-bending performance.It is usually used in various machine structures and institutions,such as shafts,connecting rods,bolts,gears and other machine tools,automobiles and tractors and other manufacturing industry using very common.Especially for the large parts in the heavy machinery manufacture.

Shot-Grinding-assembly.Processing of automotive crankshaft 40Cr material:Cutting-Forged-normalizing-rough-surface hardening and tempering - finishing.

① high bending fatigue strength and contact fatigue strength (resistance to fatigue pitting)② tooth surface with high hardness and wear resistance

③The heart of gear unit has enough strength and toughness. 

Hardness: 

①20CrMnTi material, 20CrMo gear: the tooth surface hardness: 58-64HRC,core hardness: HRC32-45 after heat treatment

②35,40,45  hardness 149-179HB after heat treatment,

③40Cr steel: the hardness is 207-241HBafter heat treatment ;

The automotive gear After heat treatment need finishing.So it is important for choosing the inserts for this.Halnn CBN insert is a good choice,it is efficiency and save processing costs.

Currently,the inserts material for processing automotive gear after heat treatment has carbide tools, ceramic cutting tools and cubic boron nitride cutting tools gear,Halnn superhard cubic boron nitride(CBN) cutting tools is the best choice.Halnn cubic boron nitride cutting tools using non-metallic (ceramic) as  a binder,adding more toughness than the ordinary CBN tool,it can not only improve the processing efficiency but also reduce the processing costs.

BN-H10 and BN-H20 belong to welding CBN inserts,BN-H10 is suitable for continuous processing,BN-H20 suit for semi-interrupt turning,BN-S20 belong to the Solid CBN insert,not only can finish turning automotive gears, but also the processing of large deformation of gear tooth surface,It has a high hardness,wear resistance and impact resistance.

PS:Hardness comparison: BN-S20 >BN-H10 >BN-H20; 

Toughness comparison: BN-S20 >BN-H20>BN-H10.

Any questions ,you can feel free to contact with us:halnntools@gmail.com,skype:cbn_inserts_angels

The solutions of CBN cutting tools machining auto cast iron parts

Auto parts are made from gray cast iron usually has a variety shape.When choose the cutting tools to machining these auto parts, we must consider the work piece gap,can’t have any interference.

 

CBN cutting tools can offer various structural characteristics of automotive cast iron parts.Select different cutting tools model number according to different parts,it not only increase productivity,but also reduce the processing costs.

 

 BN-S30 cbn insert roughing disk brakes

1.Machining Auto parts disk brakes

① Roughing:Select non-metallic adhesive CBN insert BN-S30 grades.

It is also suitable for the finishing process,when roughing disk brakes,we often choose rhombus inserts and square inserts.It has high processing efficiency,and also get well precision.For example,CNMN120416,CNMN120718;SNGN120412;SCGN0904 grades are usually used for roughing disc brakes CBN insert.

 

Non-metallic binder CBN inserts BN-S30 grades features:

1.High hardness,good wear resistance;

2.Non-metallic (ceramic) as a binder,a strong impact toughness;

3.Good stability and good reliability;

4.It can meet all kinds of machine tools cutting processing;

5.-speed cutting efficiency high;

6.Dry Cutting reduce environmental pollution;

 

②Fine finishing:Cubic boron nitride inserts BN-K20 belong welded CBN inserts

BN-S300 CBN insert milling enginee block

It only suit for a small margin for fine finishing process.It has many models,such as the triangle,rhombus,and international model VNGA120408;WNGA080408;TNGA160408.Fine finishing cutting speed can reach up to 1500m/min.The cutting tool can withstand high-speed cutting in the case of machine tool rigidity enough.Processing efficiency is 20 times of coated carbide inserts.

 

2. Machining Auto parts engine block

Automobile parts engine cylinder mainly adopts milling processing,China launched solid cubic boron nitride inserts BN-S300 grades,can high efficiently milling engine block.Such cutting tools are more wear-resistant,higher processing precision,overall rigidity and stability is very good,especially suitable for the milling engine cylinder surface.

BN-S300 CBN inserts fine milling engine block cutting parameters:ap = 0.3mm, Fz = 0.12mm / r, line speed n = 2800,Vc=1700m/min.

Compared to imports PCBN inserts,3670mm/min feed rate,BN-S300 grades cubic boron nitride cutting tool life is higher than imports PCBN cutting tools, and cutting tool costs is less than imported PCBN inserts.

 

3. Machining Auto parts belt pulley

Auto Parts belt pulley finishing cutting tool selection BN-K20 grades. BN-K20 grades cutting tools are

BN-K20 hard turning insert finishing Belt pulley

mainly used for gray cast iron fine finishing procedure. In addition to the processing belt pulleys,BN-K20 grades cubic boron nitride inserts can also be processed clutch pressure plate, flywheel, axles axle housing and other gray cast iron materials.

Cutting parameters: ap = 0.3mm, Fr = 0.25mm / r, Vc = 550-700m / min. Compared to coated carbide cutting tools: not only ensures a good belt pulley roughness and cutting tool life is 5.5-6 times of coated carbide cutting tool.

 

China always devote to researching new cbn materials to help customers solve their problems on hard turning hard materials.

Halnn superhard,as the leader brand of CBN insert in China ,always devote to researching new cbn materials to help customers solve their problems on hard turning hard materials .

Any questions on hard turning ,you can feel free to contact with ushalnntools@gmail.com .skype :cbn_inserts_angels

Three industry widely used superhard cutting tools

Through many years research and practical ,superhard cutting tools has realized turning instead of grinding which bring huge economic profit. In current times, superhard cutting tools mainly used in hard turning high hardness materials work piece, and it is widely used in the following industry: Mill Rolls,Pump Part and Automotive Parts industry.

Halnn will analyze why superhard cutting tools can be used in these industry .

 Part 1 The reasons of superhard cutting tools widely used in mill rolls ,pump and automotive industry

(1) Most Mill Rolls are castings,and it will have some defects such as sand,airhole,and it brings difficulty for machining

(2) Most automotive parts will use heat treating process to improve the performance of the work piece, and it will have high hardness after heat treating,and will probably deformed.

(3) The three work piece belongs to consumption ,and has high rate in machinist industry, has huge requirement.

 Part 2 The processing efficiency with superhard cutting tools in Mill Rolls，Pump and Automotive Parts industry 

1. Mill Rolls industry

Many manufacturers used chilled cast iron and high chrome cast iron as the main materials of the mill rolls. Beacuse of high hardness and casting defects ,the mill rolls will difficult to machining with normal cutting tools ,so many manufacturers will use superhard cutting tools rough and finish machining mill rolls .Superhard tools not only improve the processing efficiency (improved 2 ~6 times) ,but also lower the processing cost(including machining time ,power cost and insert costs)

If one mill rolls manufacturer use Halnn BN-K1 CBN inserts machining chilled cast iron with hardness HS60~80,cutting speed improved 3 times.

2. Pump industry

The pump parts are widely used in mining machinist ,heavy machine and powder industry. Because of the bad working environment ,when machining the Pump ,it often use cast iron parts with better performance so that make sure the usage lifetime. But for so high hardness pump work piece, such as the guard with hardness HRC63~67,it will be difficult to machining .

Traditional process is annealing first ,then rough machining ,last quenching. If with superhard insert ,especially Halnn Tools researched BN-K1 CBN insert ,it will just only one step to hard turning ,saved two processes, saved much time and powder ,lower the processing cost. And now about 70~80% pump industry manufacturers are using superhard tools .

3. Automotive Parts industry

Many automotive parts belongs to hardened parts, it will often meet problems on machining hardened parts. For example , when machining bearing inner ring which main materials are GCr15 steel ,hardness HRC60,the diameter is 285mm, it will use grinding first ,but the allowance will not Uniform, and it need 2 h. After using superhard tools ,it only need 45min to machining a inner ring .

 Part 3 Conclusion

Even though above three industry are widely used superhard cutting tools,but there are also many manufacturers know little about superhard cutting tools on hard turning ,and thought that it only can use grinding process on machining hard materials,and the costs on superhard cutting tools is so high.

So Halnn Tools which devote to researching new cutting tools materials to solve the problems on hard turning will help you know more about this new technology. 

More information ,http://www.halnntools.com/news/focus/224.html ,Or contact with us halnntools@gmail.com .skype:cbn_inserts_angels

Halnn superhard launched new hard turning inserts BN-S20 for processing high hardness thermal spray welding parts

Halnn superhard launched new hard turning inserts BN-S20 for hard turning high hardness spray welding parts

Thermal spray welding typically include nickel-based alloys,iron-based alloys and cobalt-based alloy spray powder.According to different alloy spray coating layer spray welding hardness were applied to repair mechanical parts or to increase the metal surface properties; Spray coating thickness usually from 0.01mm to a few millimeters; Spraying coating/spray layer hardness ≥HRC50;Some spray welding layer hardness ≥HRC65;When the cutting tools of spray coating layer and spray welding layer always is to limit hard surface later period processing technology problems.

Compared with the sprayed coating,spray welding layer owns more significant advantage. However,due to the temperature up to 900 ℃ after matrix local heating in remelting processing,it will have a greater thermal deformation.

The Performance of Halnn BN-S20 cutting tool used for Machining spray welding layer:

1.BN-S20 CBN Cutting Tools is suitable for machining high hardness spray welding layer of the surface hardness HRC45-79,such as machining Ni60,Fe65 and tungsten carbide spray welding layers of surface hardness HRC65 .

2. BN-S20 grades superhard cutting tool is a CBN cutting tool material grades,Halnn superhard cutting tool independent research and development aiming at high hardness and processing properties of an alloy build-up welding layer and spray welding layer is a national key scientific and technological project results,utility model patents products.

3. Suitable for cutting processing spray coating and spray welding hard surface as following:A variety of hard surface cutting processing about flame spraying, powder coating oxyacetylene flame,oxyacetylene flame wire spray,oxyacetylene flame spray, HVOF,arc spraying,plasma spraying,atmospheric plasma spraying,cutting low pressure plasma spraying etc.

4. Suitable for cutting the following materials spray welding layer and sprayed layer: WC spray welding layer, nickel-based alloy spray welding layer, cobalt-based alloy build-up welding layer, Hastealloy spray welding layer, Ni60 spray welding layer,88WC12CO, 86WC10CO4Cr and carbonized chromium removal spray welding layer; and suitable for high hardness alloy steel roughing and finishing.BN-S20 grades cutting tool processing spray welding layer and build-up welding layer cutting parameters :

Processing Case A: 

BN-S20 grades cutting tool is a machine folder indexable inserts, also suitable for processing spray welding layer and spray layer hard surface: WC spray welding layer, nickel-based alloy spray welding layer, cobalt-based alloy build-up welding layer,

For example, processing cobalt-based alloy spray coating materials,Spray coating layer thickness: 2mm; Spray coating layer hardness:HRC60;Linear speed: V = 70--130m / min;Feed rate:0.7~

0.8mm/ r;Cutting Depth: ap=1.7mm;Cutting tool life: the life of each blade edge 150 minutes; 8 

cutting edge;

Processing Case B:

For example, processing hardness more than HRC65 of tungsten carbide spray welding layer, adopt the line speed :V = 85M / min; feed amount: ap = 0.65mm; BN-S20 processing efficiency and cutting tool life exhibited irreplaceable advantages.

Processing Case C: 

Machining nickel base alloy spray welding layer,adopting the line speed :Vc = 180m / min high-speed cutting; Use life is 6--10 times of ceramic inserts.

Hastelloy spray welding layer, Ni60 spray welding layer, 88WC12CO, 86WC10CO4Cr and carbonized chromium spray welding layer processing; BN-S20 cutting tool can process hardness over HRC65 spray welding layer and the spray layer,BN-S20 is a composite hard surface machining and superhard processing cutting tools special grades.

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