CN105886933A

CN105886933A - High tempering softness resistance and high tenacity hot-work die steel and manufacturing method thereof

Info

Publication number: CN105886933A
Application number: CN201610312870.1A
Authority: CN
Inventors: 王飞
Original assignee: Tianjin Gang Yanhai Moral Science And Technology Ltd
Current assignee: Tianjin Gang Yanhai Moral Science And Technology Ltd
Priority date: 2016-05-12
Filing date: 2016-05-12
Publication date: 2016-08-24
Anticipated expiration: 2036-05-12
Also published as: CN105886933B

Abstract

The invention discloses high tempering softness resistance and high tenacity hot-work die steel and a manufacturing method thereof. The hot-work die steel comprises, by weight percent, 0.35%-0.45% of C, 0.15%-0.35% of Si, 0.5%-0.7% of Mn, 4.5%-5.0% of Cr, 1.5%-1.9% of Mo, 0.2%-0.5% of V, 0.1%-0.2% of Ni, 0.002%-0.012% of P, 0.0001%-0.0005% of S, 0.003%-0.009% of rare earth and the balance Fe. The method comprises the following steps that firstly, refining is conducted in an intermediate frequency furnace and an LF, C, Si, Mn, Cr, Mo, V, Ni, P, S and Fe are placed in the intermediate frequency furnace to be smelted, the content of tapping P is controlled to range from 0.002% to 0.012%, alloy component adjustment and desulfuration are conducted through refining of the LF, and the content of S is controlled to range from 0.001% to 0.003%; secondly, VD degassing and rare earth adding are conducted, the oxygen content in steel is controlled to range from 10 ppm to 20 ppm through a VD furnace, a rare earth composite line is added in the VD furnace, and the content of the steel grade rare earth is controlled to range from 0.003% to 0.009%; and thirdly, argon protection pouring is conducted, pouring is conducted under argon protection, and oxygen in the atmosphere is prevented from being dissolved in steel. According to the high tempering softness resistance and high tenacity hot-work die steel and the manufacturing method thereof, higher tempering softness resistance and higher tenacity are achieved, the service life of the hot-work die steel is prolonged by 1.5-2.0 times compared with the service life of H13, the using efficiency of a die is improved, and the production cost is reduced.

Description

A kind of high anti-temper softening and the hot die steel of high tenacity and manufacture method thereof

Technical field

The present invention relates to technical field of hot working die steel, particularly relate to a kind of high anti-temper softening Hot die steel and manufacture method thereof with high tenacity.

Background technology

Have with mould machine-shaping part that production efficiency is high, quality is good, save material and cost The series of advantages such as low, range of application and extensively；Hot-work die high temperature to be contacted Metal (liquid or solid-state), bear mechanical force, frictional force and alternating thermal stress and machinery Stress, make mould easily produce fracture, plastic deformation, wear and tear, soften, the inefficacy shape such as tired Formula, this just requires that heat is made mould and had outstanding intensity, toughness, plasticity, wearability, resists back Fire softening performance, uses experience, wherein special toughness and anti-temper softening performance according to each mould factory It is even more important.

H13 is one of the most frequently used hot work tool steel, is opened in the second half in last century by the U.S. the earliest Sending out, owing to it has the most excellent quenching degree, and good toughness, wearability are high, heat exhaustion The feature such as good, in hot die steel, the combination property of H13 is the most prominent, and therefore, it is fast The rapid-result heat for world does mould steel；Being mainly characterized by of H13 steel: (1) has high Quenching degree and high toughness；(2) excellent thermal crack resistant ability, can give water-cooled in workplace； (3) there is medium wear resistance, it is also possible to use carburizing or nitridation process to improve its table Surface hardness, but outline is for reducing thermal crack resistant ability；(4) relatively low because of its phosphorus content, in tempering two Underhardening ability is poor；(5) there is anti-softening ability at relatively high temperatures, but use temperature high Occur declining (operating temperature being i.e. resistant to is 540 DEG C) rapidly in 540 DEG C of (1000 °F) hardness； (6) deformation of heat treatment is little；(7) medium and high machinability；(8) medium anti-de- Carbon ability.

Along with high speed, strong load, high-accuracy forging equipment and high-strength tenacity forging are commonly used, Hot-work die service condition is more severe, and H13 causes multiple the most because of various reasons Failure mode, therefore, the present invention proposes the heat work of a kind of high anti-temper softening and high tenacity Mould steel and manufacture method thereof.

Summary of the invention

The technical problem existed based on background technology, the present invention proposes a kind of high anti-temper softening Property and the hot die steel of high tenacity and manufacture method thereof.

A kind of high anti-temper softening of present invention proposition and the hot die steel of high tenacity, including The chemical composition content of following percentage by weight meter: C 0.35-0.45%, Si 0.15-0.35%, Mn 0.5-0.7%, Cr 4.5-5.0%, Mo 1.5-1.9%, V 0.2-0.5%, Ni 0.1-0.2%, P 0.002-0.012%, S 0.0001-0.0005%, rare earth 0.003-0.009%, surplus is Fe。

Preferably, including the chemical composition content of following percentage by weight meter: C 0.40-0.45%, Si 0.25-0.35%, Mn 0.6-0.7%, Cr 4.8-5.0%, Mo 1.7-1.9%, V 0.3-0.5%, Ni 0.15-0.2%, P 0.008-0.012%, S 0.0003-0.0005%, rare earth 0.005-0.009%, surplus is Fe.

Preferably, steel grade oxygen content is 5-10ppm.

The invention allows for the hot die steel of a kind of high anti-temper softening and high tenacity Manufacture method, comprises the following steps:

S1: intermediate frequency furnace and LF stove refine: by C, Si, Mn, Cr, Mo, V, Ni, P, S Putting into intermediate frequency furnace melting with Fe, controlling tapping P is 0.002-0.012%, then passes through LF Refine adjusts alloying component and desulfurization, and control S is 0.001-0.003%；

S2:VD deaerates and adds rare earth: controlling oxygen content in steel by VD stove is 10-20ppm, In VD stove, add rare earth recombination line, control steel grade content of rare earth at 0.003-0.009%；

S3: argon for protecting pouring: pour into a mould under argon shield, prevents from dissolving in steel air In oxygen；

S4: atmosphere protection electroslag: by steel ingot by atmosphere protection electroslag technology remelting, improves steel Degree of purity, oxygen sulfur content is reduced to 3-5ppm, and improves the curing condition of steel, thus Fall improves steel ingot compactness and structural homogenity；

S5: High temperature diffusion: steel ingot is carried out at 1240-1280 DEG C High temperature diffusion, during insulation Between be 12-30 hour；

S6: six sides forging: steel ingot is carried out six sides forging, is incubated at 1200-1300 DEG C 2-2.5 hour, opening forging at 1150-1250 DEG C, final forging temperature is 800-1000 DEG C；

S7: thin brilliant heat treatment technics: the steel ingot after forging is incubated 5-30 at 1100-1200 DEG C Hour, then mist is cooled to 400-600 DEG C, to eliminate proeutectoid carbide intercrystalline precipitation；

S8: spheroidizing: shove charge at 300-500 DEG C, is then incubated at 850-870 DEG C 8-15 hour, at 700-750 DEG C, it is incubated 15-35 hour with 20-25 DEG C of cooling rate slow cooling, then With the speed slow cooling of 20-25 DEG C to 400-600 DEG C, air cooling of coming out of the stove.

Preferably, in described S1, intermediate frequency furnace and LF stove refine: by C, Si, Mn, Cr, Mo, V, Ni, P, S and Fe put into intermediate frequency furnace melting, and controlling tapping P is 0.008-0.012%, Then adjusting alloying component and desulfurization by LF refine, control S is 0.002-0.003%.

Preferably, in described S2, VD deaerates and adds rare earth: control oxygen in steel by VD stove Content is 15-20ppm, adds rare earth recombination line in VD stove, controls steel grade content of rare earth and exists 0.005-0.009%.

Preferably, in described S6, six sides forging: steel ingot is carried out six sides forging, It is incubated 2-2.3 hour at 1250-1300 DEG C, at 1200-1250 DEG C, opens forging, final forging temperature For 900-1000 DEG C.

Preferably, in described S7, thin brilliant heat treatment technics: the steel ingot after forging is existed Being incubated 10-30 hour at 1150-1200 DEG C, then mist is cooled to 500-600 DEG C, to eliminate two Secondary carbide intercrystalline precipitation.

Preferably, in described S8, spheroidizing: shove charge at 400-500 DEG C, then exist It is incubated 10-15 hour at 860-870 DEG C, protects at 730-750 DEG C with 22-25 DEG C of cooling rate slow cooling Temperature 25-35 hour, then with the speed slow cooling of 22-25 DEG C to 500-600 DEG C, air cooling of coming out of the stove.

In the present invention, matrix is pure, even tissue to utilize this technical scheme to obtain, without bulk The hot die steel of primary carbide, compared with H13 steel, has higher anti-temper softening With higher toughness, improve 1.5-2.0 times compared with H13, improve mould service life Service efficiency, reduces production cost, can make steel carbide spheroidization, size to fit, it is simple to Machining, the present invention reduces silicon, content of vanadium to improve the toughness of material on the basis of H13 steel； Improve molybdenum content to make up and reduce the loss of strength of steel after silicon and vanadium, and improve the anti-temper softening of steel Performance；Add nickel and make up the partial action reducing Si, and improve the toughness of steel；Add rare earth The purity of steel, uniformity, crystal grain refinement can be improved and improve the thermoplasticity etc. of high-alloy steel and make With, also make up the partial action of vanadium.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is explained orally further.

Embodiment one

The present embodiment proposes a kind of high anti-temper softening and the hot die steel of high tenacity, bag Include the chemical composition content of following percentage by weight meter: C 0.35%, Si0.15%, Mn 0.5%, Cr 4.5%, Mo 1.5%, V 0.2%, Ni 0.1%, P 0.002%, S 0.0001%, rare earth 0.003%%, surplus is Fe.

The present embodiment also proposed a kind of high anti-temper softening and the hot die steel of high tenacity Manufacture method, comprise the following steps:

S1: intermediate frequency furnace and LF stove refine: by C, Si, Mn, Cr, Mo, V, Ni, P, S Putting into intermediate frequency furnace melting with Fe, controlling tapping P is 0.002%, is then adjusted by LF refine Whole alloying component and desulfurization, controlling S is 0.001%；

S2:VD deaerates and adds rare earth: controlling oxygen content in steel by VD stove is 10ppm, VD stove adds rare earth recombination line, controls steel grade content of rare earth 0.003%；

S4: atmosphere protection electroslag: by steel ingot by atmosphere protection electroslag technology remelting, improves steel Degree of purity, oxygen sulfur content is reduced to 3ppm, and improves the curing condition of steel, thus drop Improve steel ingot compactness and structural homogenity；

S5: High temperature diffusion: steel ingot carries out at 1240 DEG C High temperature diffusion, and temperature retention time is 12 hours；

S6: six sides forging: steel ingot is carried out six sides forging, is incubated 2 hours at 1200 DEG C, Opening forging at 1150 DEG C, final forging temperature is 800 DEG C；

S7: thin brilliant heat treatment technics: the steel ingot after forging is incubated 5 hours at 1100 DEG C, Then mist is cooled to 400 DEG C, to eliminate proeutectoid carbide intercrystalline precipitation；

S8: spheroidizing: shove charge at 300 DEG C, is then incubated 8 hours at 850 DEG C, It is incubated 15 hours at 700 DEG C with 20 DEG C of cooling rate slow cooling, then with the speed slow cooling of 20 DEG C extremely 400 DEG C, air cooling of coming out of the stove.

Embodiment two

The present embodiment proposes a kind of high anti-temper softening and the hot die steel of high tenacity, bag Include the chemical composition content of following percentage by weight meter: C 0.45%, Si0.35%, Mn 0.7%, Cr 5.0%, Mo 1.9%, V 0.5%, Ni 0.2%, P 0.012%, S 0.0005%, rare earth 0.009%, surplus is Fe.

S1: intermediate frequency furnace and LF stove refine: by C, Si, Mn, Cr, Mo, V, Ni, P, S Putting into intermediate frequency furnace melting with Fe, controlling tapping P is 0.012%, is then adjusted by LF refine Whole alloying component and desulfurization, controlling S is 0.003%；

S2:VD deaerates and adds rare earth: controlling oxygen content in steel by VD stove is 20ppm, VD stove adds rare earth recombination line, controls steel grade content of rare earth 0.009%；

S4: atmosphere protection electroslag: by steel ingot by atmosphere protection electroslag technology remelting, improves steel Degree of purity, oxygen sulfur content is reduced to 5ppm, and improves the curing condition of steel, thus drop Improve steel ingot compactness and structural homogenity；

S5: High temperature diffusion: steel ingot carries out at 1280 DEG C High temperature diffusion, and temperature retention time is 30 hours；

S6: six sides forging: steel ingot is carried out six sides forging, is incubated 2.5 little at 1300 DEG C Time, at 1250 DEG C, open forging, final forging temperature is 1000 DEG C；

S7: thin brilliant heat treatment technics: the steel ingot after forging is incubated 30 hours at 1200 DEG C, Then mist is cooled to 600 DEG C, to eliminate proeutectoid carbide intercrystalline precipitation；

S8: spheroidizing: shove charge at 500 DEG C, is then incubated 15 hours at 870 DEG C, It is incubated 35 hours at 750 DEG C with 25 DEG C of cooling rate slow cooling, then with the speed slow cooling of 25 DEG C extremely 600 DEG C, air cooling of coming out of the stove.

In embodiment, determine the content of steel grade alloy according to each alloys producing:

Carbon: carbon is to improve one of material quenching degree and the most important element of hardenability, the most also may be used To form alloy carbide, improving wearability, but addition is too much, quenching structure is high-carbon Martensite, fragility is big, and therefore, its content controls at 0.35-0.45%.

Silicon: steel grade addition silicon is in addition to the effect playing deoxidation, and silicon plays solution strengthening also into matrix Effect, improves intensity and the wearability of steel；Silicon addition is too much, easily produces segregation, therefore Silicone content is controlled at 0.15-0.35%.

Manganese: manganese can also improve the quenching degree of steel, but, addition is too much, in quenching structure Retained austenite is too much, reduces H13 wearability on the contrary.

Chromium: add chromium in steel primarily to improve high-temperature behavior, it is ensured that high temperature undertissue and property Can be stable, chromium is the element reducing γ phase region, and addition is too much, easily occurs low in quenching structure The ferrite of hardness；And chromium also can improve the brittle transition temperature of steel, promote the temperature tempering of steel Fragility, therefore, its addition controls at 4.5-5.0%.

Vanadium: V Yu O, N have the biggest affinity, and one is strong carbide element, and general VC is more Divergence is the highest, and stabilizer pole；So fine and close fine grained texture can be obtained with deoxidation, degassing, improve Plasticity, toughness, intensity, wearability, but it is unfavorable for carburizing；Owing to VC disperse stops weld seam Crystal grain is grown up, can be with improving welding property；Vanadium improves high-temerature creep and the creep rupture strength of steel, carries The heat resistance of Gao Gang；Being solid-solution in austenite the quenching degree that can improve steel, compound state can reduce The quenching degree of steel, increases steel belt roof bolt stability, and has the strongest post-curing effect, solid solution Extremely strong solution strengthening effect is had in ferrite；But content of vanadium adds too much can the toughness of first steel And plasticity, make machining become difficulty.So content of vanadium controls at 0.2-0.5%.

Molybdenum: molybdenum adds in steel, mainly improves the anti-temper resistance mainly improving steel, and Eliminate steel belt roof bolt fragility；Easily occur when molybdenum content is more that 6 phases or other brittlement phase two make toughness Reduce, also promote decarburization, reduce thermal conductivity, so molybdenum content controls at 1.5-1.9%.

Ni: nickel can improve intensity, quenching degree, plasticity and toughness, improves the corrosion resistance of steel, It is used in combination with Cr and Mo, improves heat resistance；But nickel addition the most easily expands austenite Phase region, increases residual austenite content.

Rare earth: the rare earth easily sulfur in steel, oxygen are combined generation high-melting-point rare earth oxide, rare earth Sulfide, rare-earth oxide sulfate, rare earth silicate, these materials can be in solidification of molten steel process Middle as non-poliosis crystallization nuclei, promote crystal grain refinement in steel；Meanwhile, rare earth element can change The form of alloy carbide Mn (Cr, w, V, Mo) C in change alloy die steel so that close Gold carbide is from needle-like, lamellar and the continuous net-shaped graininess becoming Dispersed precipitate or spherical carbonization Thing form, thus improve tissue and the performance of steel.

Sulfur: harmful element；Reduce intensity and the toughness of steel；Hot die steel drops as far as possible Low sulfur content, controls sulfur at below 5ppm in this product.

Phosphorus: harmful element, improves the brittle transition temperature of steel；Make welding performance degenerate, reduce Plasticity, makes clod wash degenerate, and increases temper brittleness (tempering intercrystalline precipitation), makes crystal grain thick Change；This product phosphorus content controls below 0.012%.

Smelting process: deaerate by intermediate frequency furnace smelting, LF stove refine, VD, feed rare-earth, Mg, Ca Recombination line, argon for protecting pouring and electroslag furnace under protective Ar gas remelting obtain meeting mentioned component requirement.

High temperature diffusion: steel ingot carries out at 1240-1280 DEG C High temperature diffusion, and temperature retention time is 12-30 hour, eliminate Aliquation carbide in process of setting, eliminate interdendritic segregation.

Forging Technology: steel ingot is carried out six sides forging, is incubated 2 hours at 1200-1300 DEG C, Opening forging for 1150-1250 DEG C, final forging temperature is more than 800 DEG C.

Thin brilliant heat treatment technics: the steel billet after forging is incubated 5-30 hour at 1100-1200 DEG C, Then mist is cooled to 400-600 DEG C, enters stove immediately after and carries out spheroidizing, to eliminate secondary carbon Compound intercrystalline precipitation.

Spheroidizing: 300-500 DEG C of shove charge, 850 DEG C-870 DEG C are incubated 8-15 hour, with little It is incubated 15-35 hour to 700-750 DEG C in 25 DEG C of cooling rate slow cooling, then with the speed less than 25 DEG C Degree slow cooling to 400-600 DEG C, air cooling of coming out of the stove.

The above, the only present invention preferably detailed description of the invention, but the protection model of the present invention Enclosing and be not limited thereto, any those familiar with the art is in the skill that the invention discloses In the range of art, according to technical scheme and inventive concept equivalent in addition thereof or change Become, all should contain within protection scope of the present invention.

Claims

1. a high anti-temper softening and the hot die steel of high tenacity, it is characterised in that Chemical composition content including following percentage by weight meter: C 0.35-0.45%, Si 0.15-0.35%, Mn 0.5-0.7%, Cr 4.5-5.0%, Mo 1.5-1.9%, V 0.2-0.5%, Ni 0.1-0.2%, P 0.002-0.012%, S 0.0001-0.0005%, rare earth 0.003-0.009%, surplus is Fe.

The heat work of a kind of high anti-temper softening the most according to claim 1 and high tenacity Mould steel, it is characterised in that include the chemical composition content of following percentage by weight meter: C 0.40-0.45%, Si 0.25-0.35%, Mn 0.6-0.7%, Cr 4.8-5.0%, Mo 1.7-1.9%, V 0.3-0.5%, Ni 0.15-0.2%, P 0.008-0.012%, S 0.0003-0.0005%, Rare earth 0.005-0.009%, surplus is Fe.

The heat work of a kind of high anti-temper softening the most according to claim 1 and high tenacity Mould steel, it is characterised in that steel grade oxygen content is 5-10ppm.

4. a manufacture method for the hot die steel of high anti-temper softening and high tenacity, its It is characterised by, comprises the following steps:

The heat work of a kind of high anti-temper softening the most according to claim 4 and high tenacity The manufacture method of mould steel, it is characterised in that in described S1, intermediate frequency furnace and LF stove refine: C, Si, Mn, Cr, Mo, V, Ni, P, S and Fe are put into intermediate frequency furnace melting, controls Steel P is 0.008-0.012%, then adjusts alloying component and desulfurization by LF refine, controls S is 0.002-0.003%.

The heat work of a kind of high anti-temper softening the most according to claim 4 and high tenacity The manufacture method of mould steel, it is characterised in that in described S2, VD deaerates and adds rare earth: logical Cross VD stove controlling oxygen content in steel is 15-20ppm, adds rare earth recombination line in VD stove, Control steel grade content of rare earth at 0.005-0.009%.

The heat work of a kind of high anti-temper softening the most according to claim 4 and high tenacity The manufacture method of mould steel, it is characterised in that in described S6, six sides forging: steel ingot is entered Row six sides forging, is incubated 2-2.3 hour, at 1250-1300 DEG C at 1200-1250 DEG C Opening forging, final forging temperature is 900-1000 DEG C.

The heat work of a kind of high anti-temper softening the most according to claim 4 and high tenacity The manufacture method of mould steel, it is characterised in that in described S7, thin brilliant heat treatment technics: will Steel ingot after forging is incubated 10-30 hour at 1150-1200 DEG C, and then mist is cooled to 500-600℃。

The heat work of a kind of high anti-temper softening the most according to claim 4 and high tenacity The manufacture method of mould steel, it is characterised in that in described S8, spheroidizing: at 400-500 DEG C Lower shove charge, is then incubated 10-15 hour, with 22-25 DEG C of cooling rate slow cooling at 860-870 DEG C It is incubated 25-35 hour at 730-750 DEG C, then with the speed slow cooling of 22-25 DEG C extremely 500-600 DEG C, air cooling of coming out of the stove.