Y40Mn is a high-sulfur, medium-carbon free cutting steel with good cutting performance, which can improve tool life by four times and productivity by 30% compared with No. 45 steel, and it has high strength and hardness, which makes it suitable for the processing of parts with high rigidity requirements, such as screws, light rods, racks, and spline shafts.
Free cutting steel (free cutting steel) in the steel to add a certain amount of one or more of the sulfur, phosphorus, lead, calcium, selenium, tellurium and other cutting elements to improve its cutting alloy steel. Also known as automatic machine tool processing steel, or simply automatic steel. This type of steel can be cut with higher cutting speeds and greater depths of cut. Due to the addition of free-cutting elements in the steel, the steel cutting resistance is reduced, while the characteristics of the free-cutting elements themselves and the formation of compounds play a role in lubricating the cutting tool, easy to break the chip, reducing the wear and tear, which reduces the surface roughness of the workpiece, improves the life of the tool and productivity.
Representation
①The steel number is crowned with "Y" to distinguish it from high-quality carbon structural steel.
② letter "Y" after the number of carbon content, the average carbon content of a few ten thousandths of the said, for example, the average carbon content of 0.3% of the free cutting steel,
the steel number for the "Y30".
3 manganese content is higher, but also in the steel number after the label "Mn", such as "Y40Mn".
Classification
Containing easy-to-cut elements can be divided into:
1) sulfur easy-to-cut steel
Sulfur in the steel and manganese and iron to form manganese sulfide inclusions, such inclusions can interrupt the continuity of the base metal, in the cutting of the broken chip to form a small and short curling radius, and easy to exclude, to reduce tool wear and reduce the roughness of the surface of the machining, and to improve the life of the tool. Usually the cutability of steel increases with the increase of sulfur content in steel. However, the longitudinal and transverse mechanical properties of steel differ greatly, transverse plasticity, toughness is poor, fatigue and corrosion resistance properties have also been reduced. When the sulfur content in steel is too high, it will lead to thermal embrittlement, the steel hot working difficulties, deteriorating the mechanical properties of steel. Usually the sulfur content of 0.08% to 0.30%, some can be increased to 0.4%, free cutting tool steel and stainless steel sulfur content should be in 0.06% to 0.10%.
Phosphorus and sulfur compound to join the steel, usually phosphorus content of 0.04% to 0.12%, phosphorus solid solution in ferrite will improve the hardness and strength, reduce toughness, so that chips are easy to break and exclude, so as to obtain a good machining surface roughness, but the phosphorus content is too high will significantly reduce the plasticity, improve the hardness, but on the cutting of the steel to play a harmful role.
(2) lead free cutting steel
Lead in steel in the form of fine metal particles, uniformly distributed or attached to the sulfide around. Due to the low melting point of lead, cutting melt oozing lubrication, reduce friction, improve cutting, but does not affect the room temperature mechanical properties. Steel lead content is generally 0.10% to 0.35%. Because the lead ratio is significant, such as the content is too high, easy to cause serious segregation and the formation of large particles of inclusions, but to reduce the lead on the cutting process favorable role. Lead and sulfur composite added to low-carbon structural steel, improve the effect of steel being cut more significantly.
(3) calcium free cutting steel
Calcium and aluminum in steel, silicon combined to form a low melting point of the composite oxide (mainly CaO?Al2O3?SiO2), high-speed cutting, calcium oxide attached to the surface of the cutting tool lubrication and friction reduction, thereby improving the service life of the tool. If at the same time containing sulfur, lead and other elements, their composite effect will make the cutting effect better.
Since the 80's with the improvement of cutting tools, calcium free cutting steel coated with T|N coating on the tool, for the tool cost of high hobbing cutter, gear cutting tools such as gear cutting tools, there are significant results.
(4) selenium, tellurium, bismuth free cutting steel
Tellurium, bismuth content of about 0.03% to 0.10%, selenium content of up to 0.15%. Selenium to selenide such as FeSe, MnSe and other forms exist in steel, its role is similar to sulfur, for both high cutting requirements, but also requires good plasticity of steel, selenium in steel than sulfur. Tellurium can be added alone, but also with lead or sulfur at the same time to join the steel, the formation of composite inclusions to reduce the cutting resistance and cutting heat, so that the chip is easy to exclude, significantly improve the cutability of the steel, to get a good machining surface roughness, but after the addition of tellurium will make the plasticity of the steel, toughness is slightly reduced. Selenium and tellurium are generally mostly used in alloy steels. Bismuth has a similar role to lead in steel, appearing as fine metal particle inclusions, evenly distributed or attached around sulfides.
Features
1 ⒈ good processing performance: the product has a smooth cutting, excellent material, stable processing, good metallurgical organization, stable chemical composition, small deviation, net steel purity, low inclusions, not easy to damage the tool and so on; extremely easy to cut in the lathe, the tool service life and productivity have increased by 40%;
Peake good plating performance: cutting processing Very easy; can drill deep holes, milling deep grooves, etc.; processing efficiency can be greatly improved than ordinary steel; good plating performance of the product can replace copper products, greatly reducing product costs;
Good finish: the surface finish of the workpiece is good after lathe machining;
Sung environmental protection: in line with the European Union's SGS environmental certification standards, and through the Swiss environmental certification. The products can be exported for machinery and equipment: woodworking machinery, ceramic machinery, paper making machinery, glass machinery, food machinery, construction machinery, plastic machinery, textile machinery, jacks, hydraulic presses, etc.
Electrical product parts: motor shafts, fan shafts, sewing machine shafts, etc.
Furniture: Especially for exporting metal furniture, such as coffee tables, chairs, outdoor furniture;
Metal Apparatus: garden tools, barbecue grill mesh frame, screwdrivers, anti-theft locks, etc.;
Main use
Free cutting steel is mainly used for the production of less force but strict requirements on size and finish of the instrumentation, watch parts, automobiles, machine tools and a variety of other machines used in the strict requirements of dimensional accuracy and finish, and relatively low requirements on the mechanical properties of the standard parts, such as gears, Shafts, bolts, valves, bushings, pins, pipe fittings, spring seat cushions and machine tool screws, plastic molding molds, surgical and dental procedures and appliances. Specifically as follows
⒈ automatic lathe processing, hardware stamping parts processing;
Pake the electronics industry, fiber optic connectors, optical disk drives, scanners, medical equipment;
3 household appliances, instrumentation industry;
sung office equipment (computers, photocopiers, cameras, fax machines, etc.);
Careful with the components of the clock, eyeglasses;
Electronic terminal pins, pins and pins, pins and pins, pins and pins, pins, pins, pins and pins, and other electronic parts. Select electronic terminal pins, timers, carburetors;
borrow ornaments, lamps, automobiles, locomotives, chains;
cleaning car sweeps, toys;
pens, handbag accessories, belt buckles, fishing gear, etc.
sneakers, studs, bolts, nuts, fittings and springs.