Exceed hard high-speed steel to have the application that go up in Leng Zunmo

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075 moulds life and the manufacturing cost that use effect will affect manufacturing industry and product upgrade. But, in a lot of enterprises that are in our country at present, the service life of the mould is lower, be equivalent to 1/3 ～ 1/5 of abroad only. According to statistic, as a result of mould life low and the rolled steel man-hour that cause and the sources of energy are wasteful, and the loss that brings to product quality influence, amount to billions of RMB every year. The life factor that affects a pattern has heat treatment of mould material, material and finishing and mould workmanship. Carry out a proof, in the mould is designed and making a process, if can choose appropriate rolled steel, decide sound heat treatment technology, appropriate arranges craft line, the potential performance to producing material adequately, reduce specific power consumption, reduce the cost, quality that improves a mould and service life to will have major effect. One, mould new steel is planted -- super- hard model new steel of high-speed steel research and development mould is planted, it is improvement and the obdurability that raise mould steel, extend the important way of the service life of the mould. Industry of our country mould is growing quickly, the data worker of our country combines native resource circumstance and characteristic on the foundation that draws lessons from foreign advanced technique, introduce and developed many new-style mould steel. The assessment that goes up through production is chosen, the steel with exceedingly good, better also technical properties plants a few function be made the welcome with use unit by the mould, make the service life of the mould reachs the level that exceeds domestic and international congener mould even, if Beijing is steely each exceeds V3N) of abbreviation of W12Cr4Mo3V3N(of hard high-speed steel without Co performance of institute and development of steelworks of big smelt metal is good, obtain country of People's Republic of China to invent award, people's Republic of China is patent (91102252) , v3N mould function raises 2 ～ with common high-speed steel than showing 10 times, be equivalent to an international market using the high-speed steel that contains 10%Co now, successfully promotion applies in be versed in the mould is produced, can make life twice increases. 2, V3N composition and V3N) of abbreviation of function characteristic W12Cr4Mo3V3N(are tungsten - molybdenum department contains nitrogen to exceed without cobalt hard model high-speed steel, the design composition of V3N sees a table 1. New-style exceeding composition of V3N of hard high-speed steel to design a characteristic is: Tall C: C provides the obdurability of steel, wearability to have conclusive effect to Leng Zunmo. The quantity that contain carbon increases, criterion compressive strength and wearability increase. Accordingly, fight concussion and Leng Zunmo of excel in pliable but strong to provide steel to contain carbon the volume is higher. Tall V: V refines grain strongly, increase wearability, red rigid and 2 hardening capacity strongly. But content is met too much apparently exasperate forgeability and grinding sex. Contain N: N can refine grain, have the effect of separate out aggrandizement again, and mechanical function and weldability can be better. Main specifications: V3N steel has hardness the red rigid with tall, good, tall wearability and certain tenacity, the application on steel is had in Leng Zunmo the effect is very distinct. This steel is compared with the high-speed steel that contain cobalt, the price is low and easy treatment, pass proper heat treatment, attainable tall hardness (HRC67 ～ 70) , tall red rigid (625 ℃ 4 hours, HRC63 ～ 65) and tall wearability, tenacity and bending strength all not under common model high-speed steel, can overcome mould point cave in and burst apart wait for inchoate attaint. 3, the method of heat treatment of treatment craft mould of V3N steel mould and the choice that machine craft want means of the working requirement according to the mould, invalidation and the diverse demand to function to decide likewise. Answer to improve heat treatment facility ceaselessly, improve heat treatment technology, make the intensity of material, tenacity gets optimal cooperate, abide by heat treatment craft strictly, control heats temperature, time, cooling rate, assure the performance characteristics of the mould thereby. Forging V3N steel contains many carbide and proeutectoid carbide, if reservation is in,quench in the organization, will reduce a mould quickly all life. Pass pair of raw material to change forge only, attack broken carbide, ability makes its show petty, even form appearance to distributing Yu Gang matrix, raise integral force to learn function. V3N steel thermal conductivity is poor, sufficient warm-up answers when forging stock heats, only then forge temperature 1170 ℃ , eventually forge temperature 950 ℃ , equipment can use 250kg(is small) with 400kg air hammer, begin to use light weight to be hit quickly, heavy hammer is used among, hit putt slow finally, the delay in box of pink of cotton of the Yu Shi after forge is cold after be being taken out, undertake anneal is handled namely. The anneal after forge can use isothermal anneal (1) seeing a picture or common anneal (2) seeing a picture the hardness after machining forge is taller, after using isotherm or common anneal, machine add can go on wheels, after quenching because labour hardness is taller, reason workpiece shapes grinding difficulty is greater, the emery wheel that can use praseodymium niobium corundum to add chromium to make undertakes grinding. Steel of V3N of heat treatment craft is in when 1230 ℃ of 1220 ～ quench, because exist not frit carbide, hardness on the low side, the department quenchs temperature is not worth; In 1260 ～ 1270 ℃ quench when, grain passes apparently big, tie overheat appearance. Choose 1240 ℃ of 1230 ～ to quench heat temperature can make carbide and alloying element dissolve adequately already go in austenite, can keep fine again grain (10 class of 10 ～ ) . V3N exceeds component of mould of hard high-speed steel to use 1230 ℃ of 1220 ～ via 550 ℃ 4 temper (3) seeing a picture, hardness is controallable in HRC64 ～ 67, specific can undertake adjustment from heat treatment craft according to the size of spare parts dimension, achieve hardness and intensity idealer cooperate, v3N exceeds hard high-speed steel and obdurability relation to express 2 to show as follows. V3N exceeds hard model there is more leftover austenite after high-speed steel quenchs, it is 25% ～ about according to determining 30% , must eliminate as far as possible decrease, for the happening that this undertakes for many times high temperature temper makes martensite transforms. After having high temperature temper 4 times, major leftover austenite produced martensite change, produce sclerotic effect 2 times. 2 times sclerotic effect temperature compares V3N steel common high-speed steel is tall 40 ℃ of 30 ～ , this one character is very precious, show V3N steel has taller red rigid. The deep cold treatment after finish machining after classics deep cold treatment, as a result of change of body of rudimental austenite Xiang Ma and the separate out that exceed fine carbide, hardness of mould spare parts and wearability will be improved further, wearability can rise 40% , shorten already temper time saved energy, improved mould service life apparently again. Process of deep cold treatment of high-speed steel mould is: → puts mould degrease into the → in heat preservation canister a few for many times infuse liquid nitrogen (196 ℃ ) → heat preservation immerses 2.

5h → takes out a mould to put 60 ～ quickly in 70 ℃ hot water. Steel of watch 2 V3N quenchs temperature and function of sexual relationship of pliable but strong 1200 ℃ 1240 ℃ of 1220 ℃ grain of 1270 ℃ Sbb(MPa) 2900 2700 2400 1900 1600 Ak(J/cm2) 44 36 27 15 10 spends 1260 ℃ (class) 11 10.

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0 4, the application that V3N steel has in Leng Zunmo and effect V3N exceed hard Leng Zunmo to provide life to all wait for life of commonly used mould to raise 3 ～ than Cr12MoV, Cr12 5 times, raise 2 ～ with common high-speed steel than showing 10 times, economic benefits is more remarkable, function of V3N steeliness mould is equivalent to an international market using the high-speed steel that contains 10%Co now. Some factory silicon steel piece die is to use the chromium steel such as CrWMn, Cr12MoV to make so, but because the stiff dough such as silicon steel is fragile, amount of reason mould consume is large, use V3N steeliness to make a pattern, economic effect is apparent, watch 3 contrast for die life. Express silicon steel of 3 different material piece blade grinds weekday of unit of data of contrast of the life that weigh a model the life of gross life developing number that frequency blade grinds makes charge CrWMnCr12MoV 4 times than the mould 10 thousand 1 6000 of 2000-3000 3-5 yuan V3N 4-5 10 thousand 1.3 million 20 400 yuan 5, epilogue V3N exceeds hard high-speed steel, suit treatment to rush cut a model into parts to wait cold make a pattern, life rises significantly. Craft of V3N steel hot-working is stricter, 1230 ℃ of 1220 ～ quench, 550 ℃ 4 1 hour temper, tall hardness, tall wearability and good tenacity can be obtained to cooperate via deep cold treatment again after finish machining, still can be opposite regularly in use process sunken model undertakes stress temper grows life with delaying going. CNC Milling