CBN insert
The advantages of CBN insert hard turning parts
With the continuous development of modern technology, more and more manufacturers are looking for the way to reduce the cost of mechanical parts and products to improve their company strength. Although the current quality of the products have been sufficient to meet the needs of the market, but its quality is constantly improving, and the cost of parts has a increasing pressure under the market pressure and the buyer's markets pressure. In order to cope with high-quality, high-cost challenges, machinery manufacturing only should seek new technology solutions to enhance the competitiveness of the enterprises. Before 1990s,the turning insert just applied for roughing before quenching process, finishing process after quenching still use the grinding way. The traditional process is Roughing-Heat-treatment (quenching)-Milling. With the continuous development of machinery manufacturing industry, more and more materials comes which is difficult to machine , so as the complex materials. It is difficult to process with the traditional turning tools, or even can not process the high strength, high hardness material. However the modern hard turning tools make it possible, and achieved very good results in production.
Part 1:The characteristics of hard turning Hard turning is to turning hardened steel as the final processing or finishing process, like some parts instead of to grinding the work piece, also known as the "turning instead of grinding." The characteristics of the hard turning: (1) high production efficiency: reducing the processing time compared with grinding way; (2) belong to clean hard turning process, in most cases, do not need to add coolant, reducing cooling equipment, reduce processing costs, and turning is convenient for recycling the chips; (3)hard cut didn’t need the special tools, special machinery and fixtures, but the grinding requires there is a grinder, hard turning can be run on the ordinary lathe or CNC lathe; (4) hard turning can make the parts get a good overall precision: most of the heat produced by hard turning can be take away with the chips, will not produce a burns and cracks surface like grinding , has excellent processing Surface Quality.
Part 2: The Technical requirements of the Hard turning (1) The work pieces of processing
BN-S20,BN-S200,BN-H11,BN-H20,BN-H21
CBN insert
The Hardness of the cutting hard work pieces was generally more than HRC45, if the hardness of the work piece is higher, it is more valuable , commonly the material of the hard turning have hardened steel (tool steel mold steel , carburizing steel, gear steel, bearing steel, etc.), high-alloy cast iron (such as high-chrome cast iron, high nickel-chromium cast iron, high manganese steel, etc.), powder metallurgy superalloy or other special materials . (2)How to choose machine when processing Machines rigidity also determines the precision of the work piece which need hard turning, if common lathes or CNC lathes have a enough rigid and can keep the soft surface roughness when machining the soft material work piece, it can process the hardened steel. (3) Blade of the turning tools Currently, the tools blade include: coated carbide tools, ceramic cutting tools and cubic boron nitride cutting tools (CBN tools) when using hard turning lathe. Choose the right tool is the only way for hard turning and high-speed cutting. a. coated carbide tools: one or more layers which wear good are coated on carbide cutting tool like: TiN, TiCN, TiAlN and Al2O3, etc., coating thickness is 2 ~ 18mm. Its advantage compared with the carbide cutting tools: ①has high hardness and wear resistance, and high temperature, compared with uncoated tools (blades), coated tools allow the cutting in a higher speed; or increase tool life at the same cutting speed, ; ⑥ as the friction coefficient was lower which between the coating material and the material processed, so the cutting force of the coated tools (blades) less than the uncoated tool (blade); ③The surface of the parts have a better quality after process with a coating knife (blade) processing. b. Ceramic insert: ceramic tool is harder than carbide cutting tools that can stand high temperatures reach 2000 degrees, has a high hardness, high strength, heat resistance, stability of high-temperature chemical, and there are abundant raw materials of ceramic cutting tools, it is said cant run out. but the biggest obvious disadvantage is that the ceramic tool was too brittle to interrupted cutting, it mainly used for the finishing process. c. CBN insert: the hardness of cbn cutting tools is higher than the carbide insert and ceramic insert, the hardness is just like diamond cutting tools, the two were known as super-hard tool. CBN tools has a high hardness, wear resistance, anti-crushing performance, but the biggest disadvantage of common CBN is brittle like ceramic insert. With continuous research and experiments, China developed a non-metallic binder super-hard cubic boron nitride insert(CBN insert), using ceramic as a binder, increasing the toughness of CBN tools. BN-K1,BN-S20,BN-S30 CBN insert which is widely used in hard turning hardened steel (hardened steel), pearlite gray iron, ductile iron high-grade, high hardness
BN-S20,BN-S200,BN-H11,BN-H20,BN-H21
CBN insert
cast iron and high temperature alloy parts, etc.
Summarize CBN insert is most suitable cutting tools materials for machining black metal, Halnn is the representative of the non-metallic binder super-hard cubic boron nitride cutting tools, leading the world-class level, and enjoying a highly reputation. Part 3 CBN insert Hard turning work piece CBN insert can hard turning the hardened steel: such as the processing gear steel, bearing steel, tool steel, tool steel and other parts, the hardness after heat treatment are generally more than HRC50, you can choose different corresponding grade and cutting parameters of BN-S20 CBN insert to solve the above parts, the following table is the parameters of how to choose different tools grade for processing different parts.
Parameters of how to choose CBN insert grade for processing different parts. Optimal cutting parameters Quenched steel parts
CBN insert for finishing
Gear
Depth of cut(mm)
Feed Rate (mm/r)
Cutting speed(m/min)
BN-H10
0.2
0.1
180
Bearing
BN-11
2.5
0.12
140
Ball screw
BN-S20
4.5
0.10
90
Synchronizer
BN-H20
0.15
0.1
170
Universal coupling
BN-H10
0.15
0.15
190
Mould
BN-S200
0.5
0.12
130
BN-H10, BN-H11, BN-H20 CBN insert all belong to welded cubic boron nitride insert, which can be used in the finishing process. BN-S200 CBN insert belong to the Solid CBN insert, also only for finishing. BN-S20 grades not only has high hardness but also has wear resistance and impact resistance, which already caused a great sensation in the tool field .
BN-S20,BN-S200,BN-H11,BN-H20,BN-H21