CN109023082A

CN109023082A - A kind of method of the ceramics particle strengthened steel of the micro biphase in original position

Info

Publication number: CN109023082A
Application number: CN201811035870.7A
Authority: CN
Inventors: 邱丰; 常芳; 姜启川; 赵庆龙; 方建儒
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2018-09-06
Filing date: 2018-09-06
Publication date: 2018-12-18

Abstract

The invention discloses a kind of methods of the ceramics particle strengthened steel of the micro biphase in original position, comprising the following steps: Step 1: by raw material aluminium powder, titanium valve, B₄Cylindrical green compact is pressed under the unidirectional axial compressive force of hydraulic press after the mixed-powder ball milling of C powder；Step 2: the cylindrical green compact is reacted by in-situ sintering is made in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle；Step 3: by the in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle is put into ladle bottom after being cut into fritter, then obtains micro in-situ nano TiC-TiB by non-oxidizing process process for making and casting process₂Particle Strengthening and Toughening steel；Step 4: by the micro in-situ nano TiC-TiB₂Particle Strengthening and Toughening steel successively carries out Homogenization Treatments technique, ultra fine-grained process technique and tempering process and obtains the micro ceramics particle strengthened steel of biphase in situ.Nano particle is brought into the melt of steel by the present invention by nano particle intermediate alloy, and the microstructure refinement and Strengthening and Toughening of steel are realized in ground.

Description

A kind of method of the ceramics particle strengthened steel of the micro biphase in original position

Technical field

The present invention relates to the micro biphase ceramic particle of high performance structures steel preparation field more particularly to a kind of original position is strong Change the method for steel.

Background technique

Steel be a kind of resourceful, production scale of collection is big, simple processing, performance are various, it is low in cost, easy to use and The advantages that capable of recycling structural material, be most popular basic raw material in production and living.Steel material exists It is still a kind of structural material that can not replace in a very long time, is the key that social development material base, industry manufacture Level is to measure the important indicator of social and economic level.In the modern society of rapid development, people to the technique of steel material and Performance made higher requirement, and be applied to for example: underground and marine facility, large span heavy duty bridge, light energy conservation automobile, Precision instrument, large capacity deposit container, aerospace equipment, weaponry, nuclear industry production equipment etc., require to provide performance more The novel high strength steel iron material high, the service life is longer.Meanwhile the reduction of earth resource and mentioning for people's environmental consciousness Height has also been proposed the new demand of energy-saving and emission-reduction to links such as the manufacture of steel material, processing, application and recycling.In this reality Under background, the research and development of novel high-performance steel material become more and more urgent task.But traditional technology means such as alloying, It is rotten to breed, roll the technological means such as plastic forming, optimization of Heat Treatment Process and carry out the performance of Strengthening and Toughening ordinary steel to a certain degree On had reached the limit, structure property regulation and the key technology of steel need to break tradition, realize and break through.With traditional Strengthening and Toughening Technology is compared, and the solidified structure and toughening technology of micro nano particle regulation steel have unique novelty, is had and is not changed Existing technical process for casting and the significant advantages such as equipment, environmentally protective realize that the structure refinement of steel, nano particle be transgranular and crystal boundary Strengthen, nanometer precipitated phase refinement and distribution regulation, Strengthening and Toughening integration regulate and control.For various sizes of ceramic particle, strengthen base The effect of body is often different.The ceramic particle size of micron-scale is larger, although stress can be easy to produce with thinning microstructure It concentrates.And the particle of nano-scale has the advantage and big specific surface area of huge quantity, before solid liquid interface being adsorbed on Edge hinders the transfer of molten matter atom, to hinder growing up for austenite dendrites.Obvious nano-sized particles are more efficient, and have It is concentrated conducive to stress is reduced, to lay a good foundation to improve toughness.But nano-sized ceramic particles and molten steel difference in specific gravity compared with Greatly, nano particle is added extremely difficult in molten steel, even if being added to dispersion of the nano particle in molten steel in molten steel is most to be difficult to resolve Certainly the problem of, liquid steel temperature height can not stir and ultrasonic disperse.Ceramic particle in molten steel, which is easy to float, becomes steel slag It removes, therefore greatly reduces the efficiency of reinforced by nanoparticles steel.

Summary of the invention

The present invention is to solve current technology shortcoming, a kind of ceramics particle strengthened steel of micro biphase in original position, Nano particle is brought into as toughener in the melt of steel by nano particle intermediate alloy, and strengthens the numerical value of composition of steel The optimization of range improves its plasticity toughness under the premise of guaranteeing to strengthen steel.

The present invention is to solve current technology shortcoming, provides a kind of micro biphase ceramic particle enhancing in original position The method of steel obdurability, within raw two-phase TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is nanoparticle vector, is passed through Nano particle is gradually released in the melt of steel by nano particle intermediate alloy, promotes the dispersion of nano particle, solves its dispersion Uneven problem effectively realizes the microstructure refinement and Strengthening and Toughening of steel.

Technical solution provided by the invention are as follows: a kind of ceramics particle strengthened steel of micro biphase in original position, the original position are micro- Measure the chemical composition and its mass percent of the ceramics particle strengthened steel of biphase are as follows:

C:0.38~0.50wt.%；Si:0.17~0.37wt.%；Mn:0.50~0.80wt.%；P:≤ 0.035wt.%；S :≤0.035wt.%；Cr:0.8~1.1wt.%；Ni :≤0.25wt.%；Cu :≤0.25wt.%；TiC- TiB₂: 0.009~0.16wt.%, Al:0.021wt.%~0.24wt.%, surplus Fe.

Preferably,

The biphase ceramic particle is TiC-TiB₂The in-situ nano two-phase TiC- of 30~40wt.% of granule content TiB₂The pre-dispersed intermediate alloy of particle, and the in-situ nano two-phase TiC-TiB₂The additive amount of the pre-dispersed intermediate alloy of particle For 0.03~0.40wt.%.

A kind of method of the ceramics particle strengthened steel of the micro biphase in original position, comprising the following steps:

Step 1: by raw material aluminium powder, titanium valve, B₄Cylindrical green compact is pressed into after the mixed-powder ball milling of C powder；

Step 2: the cylindrical green compact is reacted by in-situ sintering is made in-situ nano two-phase TiC-TiB₂Particle divides in advance Dissipate intermediate alloy；

Step 3: by the in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle is put into steel after being cut into fritter Bottom is wrapped, micro in-situ nano TiC-TiB is then obtained by non-oxidizing process process for making and casting process₂Particle Strengthening and Toughening Steel；

Step 4: by the micro in-situ nano TiC-TiB₂Particle Strengthening and Toughening steel successively carry out Homogenization Treatments technique, Ultra fine-grained process technique and tempering process obtain the micro ceramics particle strengthened steel of biphase in situ.

Preferably, the raw material B₄C powder passes through ball milling activating pretreatment；

The raw material aluminum powder particle size is 13~75 μm, purity 99.0wt.%；

The raw material titanium valve granularity is 13~48 μm.

Preferably,

Aluminium powder mass fraction is 60wt.% in the mixed-powder, and titanium valve mass fraction is 28.872wt.%, B₄C silty Amount score is 11.128wt.%.

Aluminium powder mass fraction is 70wt.% in the mixed-powder, and titanium valve mass fraction is 21.655wt.%, B₄C silty Amount score is 8.345wt.%.

Preferably, the step 2 specifically includes the following steps:

Step a, it is put into cylindrical graphite mold after wrapping up the cylindrical green compact with thin graphite paper, at the top of green compact High-strength graphite compression bar is placed, mold and graphite compression bar are integrally put into vacuum heating-press sintering by the position of fixed green compact in a mold In furnace, furnace pressure is evacuated to lower than 0.001Pa；

Step b, it is heated with the speed that heating speed is 25~60K/min, when temperature is increased to 573K, progress 10~ The vacuum degassing of 20min；When temperature continues to be increased to 773K, 15~25min is kept the temperature；

Step c, continue to increase temperature with 30~60K/min of heating rate to 1173K~1200K, observe vacuum hotpressing After the air pressure of pressure gauge in sintering furnace is greater than 100Pa, stop heating after keeping the temperature 10~30min；When temperature is down to 1053K, Axial 45~75MPa pressure is applied to cylindrical green compact, keeps 30~90s of pressure of the application；It is cooled to room temperature in a vacuum After obtain the pre-dispersed TiC-TiB of two-phase₂Ceramic particle intermediate alloy.

Preferably, in the step 3,

Choose nanometer two-phase TiC-TiB₂Granule content is the in-situ nano two-phase TiC-TiB of 30~40wt.%₂Particle is pre- Disperse intermediate alloy fritter, and the intermediate alloy content is 0.03wt.%~0.40wt.%.

Preferably, in the step 3, the non-oxidizing process steel-making is specifically included:

Steel is cut into the bulk of 1000~2000g, is then placed in the medium-frequency induction furnace burner hearth of 50Kg, 3~5g is added Fine aluminium slagging-off goes out molten steel at 1600~1700 DEG C of temperature；Molten steel is injected into ladle, the in-situ nano two-phase TiC- in ladle TiB₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and nano-TiC particle is poured in ladle and is scattered in molten steel.

Preferably, in the step 3, the casting process is specifically included:

It is respectively the 40mm that goes to the bottom, upper bottom that molten steel in ladle, which is at the uniform velocity poured into size at 1400~1500 DEG C or so, 60mm, high 180mm, the SiO of long 300mm₂In sand mold, micro two-phase TiC-TiB in situ is obtained₂Particle Strengthening and Toughening steel.

Preferably,

In the step 4, the Homogenization Treatments technique includes:

It will micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel is put into vacuum atmosphere oven with 200~250K's per hour Heating speed is heated to 1200~1250K, then homogenization heat preservation；Then must be homogenized by cooling to room temperature with the furnace by micro pair in situ Phase TiC-TiB₂Particle Strengthening and Toughening steel；

Wherein, the homogenization soaking time t₁Meet:

t₁=2h₁+30；

Wherein, h₁For micro two-phase TiC-TiB in situ₂The thickness of particle Strengthening and Toughening steel；

The ultra fine-grained process technique includes:

It will homogenization micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel is put into vacuum atmosphere oven with per hour 100~ The heating speed of 180K is heated to 873K~923K, keeps the temperature 20~40min, continues fine after being heated to 1223~1323K and protects Temperature, oil is cold rapidly, quenches to obtain fine micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel；

Wherein, the fine soaking time t₂Meet:

t₂=h₂/2；

Wherein, h₂For homogenization micro two-phase TiC-TiB in situ₂The thickness of particle Strengthening and Toughening steel；

The tempering process includes:

By fine micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel is put into vacuum atmosphere oven with per hour 100~ The heating speed of 150K is heated to 473~523K, keeps the temperature 6~10h, in air cooling micro biphase ceramics in situ Grain strengthens steel.

It is of the present invention the utility model has the advantages that nano particle is brought into the melt of steel by nano particle intermediate alloy, Due to the nano particle of intermediate alloy be it is pre-dispersed, nano particle is separated by aluminum substrate in intermediate alloy, will not be occurred A large amount of nanoparticle agglomerates, after entering in molten steel, the nano particle in intermediate alloy is gradually released in molten steel, promotes to receive The dispersion of rice grain.Mismatch is low between TiC ceramic particle and steel melt, and interface cohesion is stablized, and lower mismatch is conducive to The wetability of particle in the base is improved, particle is easy to realize half coherence or almost symbiosis and epibiosis between matrix.

Under best intensified condition, by adding nanometer two-phase TiC-TiB₂After ceramics particle strengthened, the yield strength of steel, Tensile strength, breaking strain, impact flexibility (U-shaped notch) have respectively to be obviously improved, and micro addition is only carried out, that is, is obtained strong Plasticity is significantly substantially strengthened.Compared with traditional toughening technology, the solidified structure of micro biphase particle regulating steel and strong Toughening technology has unique novelty, has and does not change existing technical process for casting and the significant advantages such as equipment, environmentally protective, Realize transgranular structure refinement, the nano particle of steel and intercrystalline strengthening, nanometer precipitated phase refinement and distribution regulation, Strengthening and Toughening integration Regulation.

Detailed description of the invention

Fig. 1 is the high power as-cast microstructure figure of low-alloy steel when being not added with nanometer diphase particles of the invention.

Fig. 2 is the high power as-cast microstructure figure for strengthening steel in the embodiment of the present invention one.

Fig. 3 is the high power as-cast microstructure figure for strengthening steel in the embodiment of the present invention two.

Fig. 4 is the high power as-cast microstructure figure for strengthening steel in the embodiment of the present invention three.

Fig. 5 is the high power as-cast microstructure figure for strengthening steel in the embodiment of the present invention four.

Specific embodiment

Present invention will be described in further detail below with reference to the accompanying drawings, to enable those skilled in the art referring to specification text Word can be implemented accordingly.

The present invention provides a kind of ceramics particle strengthened steel of the micro biphase in original position, the micro biphase pottery in original position The chemical composition and its mass percent of porcelain particle strengthening steel are as follows:

The present invention also provides a kind of methods of the ceramics particle strengthened steel of the micro biphase in original position, comprising the following steps:

Step 1: by raw material aluminium powder, titanium valve, B₄In the unidirectional axial compressive force of hydraulic press after the mixed-powder ball milling mixing of C powder Under be pressed into cylindrical green compact；

Step 3: by the in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle is put into steel after being cut into fritter Bottom is wrapped, micro in-situ nano TiC particle Strengthening and Toughening steel is then obtained by non-oxidizing process process for making and casting process；

Step 4: the micro in-situ nano TiC particle Strengthening and Toughening steel is successively carried out Homogenization Treatments technique, crystal grain surpasses Micronization processes technique and tempering process obtain the micro ceramics particle strengthened steel of biphase in situ.

The raw material B₄C powder passes through ball milling activating pretreatment: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 0.5~3 μm；Ratio of grinding media to material is 100:1, sets 200~350r/min for the ball milling speed of batch mixer, Ball-milling Time is 0.5~ 3h。

The raw material aluminum powder particle size is 13~75 μm, purity 99.0wt.%；

The raw material titanium valve granularity is 13~48 μm.

Aluminium powder mass fraction is 60wt.% in the mixed-powder, and titanium valve mass fraction is 28.872wt.%, B₄C silty Amount score is 11.128wt.%；

Prepared mixed-powder is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, 7mm, 11mm, The ZrO of 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, mixed-powder and zirconium oxide The overall volume of abrading-ball is no more than the 3/4 of tank body volume；Ball grinder is installed in planetary batch mixer, the revolving speed setting of batch mixer For 20~80r/min, the mixed uniformly time is 8~48h.

The step 2 specifically includes the following steps:

In the step 3,

Selection intermediate alloy mass content is 0.03wt.%~0.40wt.%, nanometer two-phase TiC-TiB₂Granule content is The in-situ nano two-phase TiC-TiB of 30~40wt.%₂The pre-dispersed intermediate alloy fritter of particle.

In the step 3, the non-oxidizing process steel-making is specifically included:

In the step 3, the casting process is specifically included:

In the step 4, the Homogenization Treatments technique includes:

Wherein, the homogenization soaking time t₁Meet:

t₁=2h₁+30

Wherein, soaking time t is homogenized₁Unit be min, h₁For micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel Thickness, unit mm.

In the step 4, the ultra fine-grained process technique includes:

Wherein, the fine soaking time t₂Meet:

t₂=h₂/2

Wherein, fine soaking time t₂Unit be min, h₂For homogenization micro two-phase TiC-TiB in situ₂Particle is strong The thickness of toughening steel, unit mm.

In the step 4, the tempering process includes:

Comparative example 1

This comparison prepares a kind of reinforcing steel for being not added with nano particle steel, and the specific method is as follows:

Using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into 1000~2000g not equal fritter, It is then placed in remelting in medium-frequency induction furnace burner hearth, the pure Al slagging-off of 3~5g is added, taps at 1600 DEG C；By molten steel at 1450 DEG C Left and right is at the uniform velocity poured into the SiO having a size of 40 (bottom) × 60 (upper bottom) × 180 (height) × 300 (length) mm₂In sand mold, obtain tough Change steel；

The main chemical compositions of Strengthening and Toughening steel are by weight percentage: C:0.42wt.%；Si:0.25wt.%；Mn: 0.60wt.%；P:0.011wt.%；S:0.019wt.%；Cr:1.0wt.%；Ni:0.20wt.%；Cu:0.12wt.%；It is remaining Amount is Fe.

Strengthening and Toughening Heat-Treatment of Steel:

A. Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 250K per hour 1250K heat preservation；(soaking time: casting thickness it is every 1 millimeter+30 minutes two minutes) then cool to room temperature with the furnace.

B. ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 180K per hour After to 923K keep the temperature (soaking time: 40 minutes), continue to heat, to 1323K after keep the temperature, (soaking time: casting thickness it is every 2 milli Rice one minute), oil is cold rapidly, quenching.

C. tempering process: sample is put into after being heated to 523K in vacuum atmosphere oven with the heating speed of 150K per hour and is protected Temperature, soaking time: 10 hours, cooling the reinforcing steel for being not added with nano particle steel in air.

In this comparative example, as shown in figure 1 and table 1, the tissue for being not added with nano particle steel is more coarse, is not added with nanometer Grain steel yield strength, tensile strength, breaking strain, impact flexibility (U-shaped notch) be respectively 1010MPa, 1110MPa, 7.0%, 16.8J/cm²。

Comparative example 2

This comparative example is nano TiC-TiB₂Total content be 0.006wt.% (be less than 0.009wt.%) nano particle Strengthen steel, the specific method is as follows:

Step 1: Al-Ti-B₄The preparation of the cylindrical green compact of C system, specific as follows:

(1) ball milling activating pretreatment B₄C powder: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 0.5 μm；Ball material Than setting 200r/min for the ball milling speed of batch mixer, Ball-milling Time is 3 hours for 100:1；

(2) weigh pure Al powder (purity 99.0wt.%) that a certain amount of granularity is 13 μm, Ti powder that granularity is 48 μm it is standby With；

(3) Ti powder and B are pressed₄C powder mass ratio is the B that 2.595:1 weighs Ti powder and mixes₄C powder；It is expected that generating TiC- TiB₂Ceramic particle accounts for the 30wt.% of entire reaction green compact；Mixing B after aluminium powder, titanium valve, ball milling are activated₄C powder is prepared At 100g mixed-powder, the wherein additive amount of each component alloyed powder are as follows: Al powder: 70wt.%；Ti powder: 21.655wt.%；B₄C Powder: 8.345wt.%；

(4) powder of prepared different component is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, The ZrO of 7mm, 11mm, 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, powder and The overall volume of zirconium oxide balls is no more than the 3/4 of tank body volume；Ball grinder is installed in planetary batch mixer, and batch mixer turns Speed is set as 20r/min, and the mixed uniformly time is 48h；

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 90MPa Lower pressure maintaining 0.5min obtains a height of 35mm, diameter of phi 30, the cylindrical green compact that consistency is 70%.

Step 2: Al-Ti-B₄C system cylindrical green compact in-situ sintering reaction prepares in-situ nano two-phase TiC-TiB₂Particle Pre-dispersed intermediate alloy, steps are as follows:

A, cylindrical green compact obtained in will be above-mentioned is wrapped with thin graphite paper, is integrally put into the circle that intracavity diameter is Φ 32mm In cylindricality graphite jig.A high-strength graphite compression bar, the position of fixed green compact in a mold are placed at the top of green compact.It will finally have The graphite jig and graphite compression bar for being fixed with cylindrical green compact are integrally put into vacuum sintering funace；Fire door is closed, is then taken out Vacuum to furnace pressure is lower than 0.001Pa.

B, it begins to warm up, heating speed is set as 60K/min；When temperature is increased to 573K, vacuum degassing 20min is carried out； When temperature is increased to 773K, 25min is kept the temperature, is consistent graphite jig temperature with cylindrical green compact temperature.

C, when temperature continuation is increased to 1200K with 60K/min, observe the pressure in vacuum sintering funace in respect of significant Variation after air pressure is greater than 100Pa, keeps the temperature 30min, then stops heating.When temperature is down to 1053K, cylindrical green compact is applied Add axial 75MPa pressure, keeps the pressure 30s of the application；The cylinder densified after reaction and through axial compressive force contains 30wt.% nano TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is cooled to room temperature in a vacuum with furnace.

Step 3: micro in-situ nano TiC-TiB₂The preparation of particle Strengthening and Toughening steel, specific as follows:

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.49wt.%；Si:0.19wt.%；Mn:0.75wt.%；P:0.015wt.%；S:0.031wt.%；Cr:0.95wt.%； Ni:0.12wt.%；Cu:0.22wt.%；Al:0.0022wt.%；The pre-dispersed intermediate alloy additional amount of in-situ nano diphase particles Are as follows: 0.02wt.%, wherein the nano TiC-TiB contained₂Total content are as follows: 0.006wt.%；Surplus is Fe.

In-situ nano two-phase TiC-TiB₂The melting and casting of the pre-dispersed intermediate alloy of particle:

A, the 30wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 2₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The alloy content that the pre-dispersed intermediate alloy of particle is is 0.02wt.%；

B, the in-situ nano two-phase TiC-TiB that previous step is prepared₂The pre-dispersed intermediate alloy fritter of particle is wrapped with aluminium foil, Then it is put into ladle bottom in advance；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into the fritter of about 2000g, is then put Enter remelting in medium-frequency induction furnace burner hearth, the pure Al slagging-off of 4g is added, taps at 1600 DEG C；Molten steel is injected into ladle, in ladle In-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and method is poured in ladle and is received in situ Rice TiC particle is scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1450 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel；

Step 4: micro in-situ nano TiC-TiB₂Particle Strengthening and Toughening Heat-Treatment of Steel:

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 250K per hour 1250K heat preservation；(soaking time: every 1 millimeter of casting thickness adds 30 minutes for two minutes) then cools to room temperature with the furnace.

B, ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 180K per hour After to 923K keep the temperature (soaking time: 40 minutes), continue to heat, to 1323K after keep the temperature, (soaking time: casting thickness it is every 2 milli Rice one minute), oil is cold rapidly, quenching.

C, tempering process: sample is put into after being heated to 523K in vacuum atmosphere oven with the heating speed of 150K per hour and is protected Temperature, soaking time: 10 hours, cooling the micro ceramics particle strengthened steel of biphase in situ in air.

In this comparative example, in the reinforcing steel, mass fraction is the in-situ nano TiC-TiB of 30wt.%₂Particle is pre-dispersed Intermediate alloy additional amount is 0.02wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.006wt.% (nano TiC- TiB₂Total content be less than 0.009wt.%)；Nanometer two-phase TiC-TiB is added by 0.006wt.%₂After ceramics particle strengthened, Yield strength, tensile strength, breaking strain, the impact flexibility (U-shaped notch) of steel be respectively 1035MPa, 1139MPa, 7.3%, 17.1J/cm², respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/cm²) be respectively increased 2.5%, 2.6%, 4.3%, 1.8%, intensity, plasticity and impact flexibility significantly improve；Obviously, 0.006wt.% nano TiC-is only carried out TiB₂Addition, without significantly strengthening the mechanical property of steel.As shown in table 1.

Comparative example 3

This comparative example is nano TiC-TiB₂Total content be 0.21wt.% (be greater than 0.16wt.%) nano particle it is strong Change steel, the specific method is as follows:

Step 1: Al-Ti-B₄The preparation of C system cylindrical green compact, specific as follows:

(1) ball milling activating pretreatment B₄C powder: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 0.5 μm；Ball material Than setting 230r/min for the ball milling speed of batch mixer, Ball-milling Time is 30 hours for 100:1；

(2) weigh pure Al powder (purity 99.0wt.%) that a certain amount of granularity is 13 μm, Ti powder that granularity is 13 μm it is standby With；

(3) Ti powder and B are pressed₄C powder mass ratio is the B that 2.595:1 weighs Ti powder and mixes₄C powder；It is expected that generating TiC- TiB₂Ceramic particle accounts for the 30wt.% of entire reaction green compact；Mixing B after aluminium powder, titanium valve, ball milling are activated₄C powder is prepared At 100g mixed-powder, the wherein additive amount of each component alloyed powder are as follows: Al alloyed powder: 70wt.%；Ti powder: 21.655wt.%； B₄C powder: 8.345wt.%；

(4) powder of prepared different component is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, The ZrO of 7mm, 11mm, 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, powder and The overall volume of zirconium oxide balls is no more than the 3/4 of tank body volume；Ball grinder is installed in planetary batch mixer, and batch mixer turns Speed is set as 60r/min, and the mixed uniformly time is 30h；

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 80MPa Lower pressure maintaining 1.5min obtains a height of 38mm, diameter of phi 30, the cylindrical green compact that consistency is 67%.

Step 2: Al-Ti-B₄C system cylindrical green compact in-situ sintering reaction prepares in-situ nano two-phase TiC-TiB₂Particle Pre-dispersed intermediate alloy:

A, cylindrical green compact obtained in will be above-mentioned is wrapped with thin graphite paper, is integrally put into the circle that intracavity diameter is Φ 32mm In cylindricality graphite jig.High-strength graphite compression bar, the position of fixed green compact in a mold are placed at the top of green compact.It finally will be with solid Surely the graphite jig and graphite compression bar for having cylindrical green compact are integrally put into vacuum sintering funace；Fire door is closed, is then taken out true Sky to furnace pressure is lower than 0.001Pa.

B, it begins to warm up, heating speed is set as 35K/min；When temperature is increased to 573K, vacuum degassing 16min is carried out； When temperature is increased to 773K, 18min is kept the temperature, is consistent graphite jig temperature with cylindrical green compact temperature.

C, when temperature continuation is increased to 1173K with 50K/min, observe that the air pressure of the pressure in vacuum sintering funace is big After 100Pa, 25min is kept the temperature, heating is then stopped.When temperature is down to 1053K, axial direction 70MPa is applied to cylindrical green compact Pressure keeps the pressure 45s of the application；The cylinder densified after reaction and through axial compressive force contains nano TiC-TiB₂Ceramics The pre-dispersed intermediate alloy of particle is cooled to room temperature in a vacuum with furnace.

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.46wt.%；Si:0.22wt.%；Mn:0.65wt.%；P:0.023wt.%；S:0.008wt.%；Cr:0.95wt.%； Ni:0.19wt.%；Cu:0.21wt.%；Al:0.024wt.%, surplus Fe.The pre-dispersed intermediate conjunction of in-situ nano diphase particles Golden additional amount are as follows: 0.70wt.%, wherein the nano TiC-TiB contained₂Total content are as follows: 0.21wt.%, surplus Fe.

Micro in-situ nano TiC-TiB₂The melting and casting of particle Strengthening and Toughening steel:

A, the 30wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 1₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle are as follows: 0.7wt.%；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into the fritter of 2000g, is then placed in Remelting in medium-frequency induction furnace burner hearth is added the pure Al slagging-off of 5g, taps at 1700 DEG C；Molten steel is injected into ladle, in ladle In-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and method in-situ nano is poured in ladle TiC particle is scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1490 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel；

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 250K per hour 1200K heat preservation；(soaking time: casting thickness it is every 1 millimeter+30 minutes two minutes) then cool to room temperature with the furnace.

B, ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 170K per hour After to 923K keep the temperature (soaking time: 20~40 minutes), continue to heat, to 1293K after keep the temperature, (soaking time: casting thickness is every 2 millimeters one minute), rapidly oil it is cold, quenching.

C, tempering process: sample is put into after being heated to 493K in vacuum atmosphere oven with the heating speed of 135K per hour and is protected Temperature, soaking time: 9 hours, cooling the micro ceramics particle strengthened steel of biphase in situ in air.

In this comparative example, in the reinforcing steel, mass fraction is the in-situ nano TiC-TiB of 30wt.%₂Particle is pre-dispersed Intermediate alloy additional amount is 0.7wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.21wt.% (nano TiC-TiB₂ Total content be greater than 0.16wt.%)；Nanometer two-phase TiC-TiB is added by 0.21wt.%₂After ceramics particle strengthened, steel is bent Taking intensity, tensile strength, breaking strain, impact flexibility (U-shaped notch) is respectively 1120MPa, 1237MPa, 4.8%, 13.7J/ cm², respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/cm²) be respectively increased 10.9%, 11.4% ,- 31.5%, -18.5%, it is clear that intensity improves, but plasticity and toughness reduce, and addition too high levels are unfavorable for the plasticity of steel and tough Property.As shown in table 1.

Embodiment one

The present embodiment is a kind of method of the ceramics particle strengthened steel of the micro biphase in original position, comprising the following steps:

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 60MPa Lower pressure maintaining 0.5min obtains a height of 35mm, diameter of phi 30, the cylindrical green compact that consistency is 70%.

B, it begins to warm up, heating speed is set as 25K/min；When temperature is increased to 573K, vacuum degassing 10min is carried out； When temperature is increased to 773K, 15min is kept the temperature, is consistent graphite jig temperature with cylindrical green compact temperature.

C, when temperature continuation is increased to 1173K with 30K/min, observe the pressure in vacuum sintering funace in respect of significant Variation after air pressure is greater than 100Pa, keeps the temperature 10min, then stops heating.When temperature is down to 1053K, cylindrical green compact is applied Add axial 45MPa pressure, keeps the pressure 30s of the application；The cylinder densified after reaction and through axial compressive force contains 30wt.% nano TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is cooled to room temperature in a vacuum with furnace.

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.50wt.%；Si:0.17wt.%；Mn:0.50wt.%；P:0.022wt.%；S:0.032wt.%；Cr:0.8wt.%；Ni: 0.18wt.%；Cu:0.10wt.%；Al:0.021wt.%, the pre-dispersed intermediate alloy additional amount of in-situ nano diphase particles are as follows: 0.03wt.% the, wherein nano TiC-TiB contained₂Total content are as follows: 0.009wt.%；Surplus is Fe.

A, the 30wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 2₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The alloy content that the pre-dispersed intermediate alloy of particle is is 0.03wt.%；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into not equal small of 1000~2000g Block is then placed in remelting in medium-frequency induction furnace burner hearth, and the pure Al slagging-off of 3g is added, taps at 1600 DEG C；Molten steel is injected into ladle It is interior, the in-situ nano two-phase TiC-TiB in ladle₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and rushes in ladle Enter method in-situ nano TiC particle to be scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1400 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel；

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 200K per hour 1200K heat preservation；(soaking time: every 1 millimeter of casting thickness adds 30 minutes for two minutes) then cools to room temperature with the furnace.

B, ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 100K per hour After to 873K keep the temperature (soaking time: 20 minutes), continue to heat, to 1223K after keep the temperature, (soaking time: casting thickness it is every 2 milli Rice one minute), oil is cold rapidly, quenching.

C, tempering process: sample is put into after being heated to 473K in vacuum atmosphere oven with the heating speed of 100K per hour and is protected Temperature, soaking time: 6 hours, cooling the micro ceramics particle strengthened steel of biphase in situ in air.

In this example, as shown in Figure 1 and Figure 2, in the reinforcing steel, mass fraction is the in-situ nano TiC- of 30wt.% TiB₂The pre-dispersed intermediate alloy additional amount of particle is 0.03wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.009wt.%；Comparison is as it can be seen that the group of low-alloy steel is woven with apparent refinement；By adding nanometer two-phase TiC-TiB₂Ceramics Grain strengthen after, yield strength, tensile strength, breaking strain, the impact flexibility (U-shaped notch) of steel be respectively 1246MPa, 1469MPa, 9.4%, 20.7J/cm², respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/cm²) respectively 23.4%, 32.3%, 34.3%, 23.2% is improved, intensity, plasticity and impact flexibility significantly improve；Obviously, it only carries out micro Addition, that is, obtain the obvious reinforcing of strong plasticity.

Embodiment two

The method of the ceramics particle strengthened steel of a kind of micro biphase in original position in this example, comprising the following steps:

(1) ball milling activating pretreatment B₄C powder: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 0.6 μm；Ball material Than setting 300r/min for the ball milling speed of batch mixer, Ball-milling Time is 1 hour for 100:1；

(2) weigh pure Al powder (purity 99.0wt.%) that a certain amount of granularity is 75 μm, Ti powder that granularity is 48 μm it is standby With；

(4) prepared powder is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, 7mm, 11mm, The ZrO of 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, powder and zirconium oxide balls Overall volume be no more than tank body volume 3/4；Ball grinder is installed in planetary batch mixer, and the revolving speed of batch mixer is set as 60r/min, mixed uniformly time are 40h；

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 70MPa Lower pressure maintaining 2min obtains a height of 40mm, diameter of phi 30, the cylindrical green compact that consistency is 62%.

B, it begins to warm up, heating speed is set as 40K/min；When temperature is increased to 573K, vacuum degassing 15min is carried out； When temperature is increased to 773K, 20min is kept the temperature, is consistent graphite jig temperature with cylindrical green compact temperature.

C, when temperature continuation is increased to 1180K with 40K/min, observe the pressure in vacuum sintering funace in respect of significant After variation, after air pressure is greater than 100Pa, 20min is kept the temperature, heating is then stopped.When temperature is down to 1053K, to cylindrical green compact Apply axial direction 55MPa pressure, keeps the pressure 60s of the application；The cylinder densified after reaction and through axial compressive force, which contains, to be received Rice TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is cooled to room temperature in a vacuum with furnace.

Step 3: micro in-situ nano TiC-TiB₂The preparation of particle Strengthening and Toughening steel:

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.42wt.%；Si:0.25wt.%；Mn:0.60wt.%；P:0.011wt.%；S:0.019wt.%；Cr:1.0wt.%；Ni: 0.20wt.%；Cu:0.12wt.%；Al:0.022wt.%；The pre-dispersed intermediate alloy additional amount of in-situ nano diphase particles are as follows: 0.18wt.% the, wherein nano TiC-TiB contained₂Total content are as follows: 0.054wt.%；Surplus is Fe.

A, the 30wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 1₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle are as follows: 0.18wt.%；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into not equal small of 1000~2000g Block is then placed in remelting in medium-frequency induction furnace burner hearth, and the pure Al slagging-off of 4g is added, taps at 1660 DEG C；Molten steel is injected into ladle It is interior, the in-situ nano two-phase TiC-TiB in ladle₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and rushes in ladle Enter method in-situ nano TiC particle to be scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1470 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel；

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 220K per hour 1220K heat preservation；(soaking time: casting thickness it is every 1 millimeter+30 minutes two minutes) then cool to room temperature with the furnace.

B, ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 140K per hour After to 900K keep the temperature (soaking time: 30 minutes), continue to heat, to 1300K after keep the temperature, (soaking time: casting thickness it is every 2 milli Rice one minute), oil is cold rapidly, quenching.

C, tempering process: sample is put into after being heated to 488K in vacuum atmosphere oven with the heating speed of 120K per hour and is protected Temperature, soaking time are 8 hours, empty wherein cooling the micro ceramics particle strengthened steel of biphase in situ.

In this example, as shown in Figure 1, Figure 3, in the reinforcing steel, 30wt.% in-situ nano TiC-TiB₂Particle is pre-dispersed Intermediate alloy additional amount are as follows: 0.18wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.054wt.%；Compared to figure 1 is not added with the mirco structure of the low-alloy steel of nanometer diphase particles, and Fig. 3 adds biphase TiC-TiB₂It is low after ceramic particle The group of steel alloy is woven with more obvious refinement, by adding nanometer two-phase TiC-TiB₂After ceramics particle strengthened, the surrender of steel is strong Degree, tensile strength, breaking strain, impact flexibility (U-shaped notch) are respectively 1254MPa, 1449MPa, 11.1%, 21.9J/cm², Respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/cm²) be respectively increased 24.1%, 30.5%, 58.6%, 30.3%, intensity, plasticity and impact flexibility significantly improve；Obviously, micro addition is only carried out, that is, obtains strong plasticity Significantly substantially strengthen.

Embodiment three

A kind of method of the ceramics particle strengthened steel of the micro biphase in original position of this example, comprising the following steps:

(1) ball milling activating pretreatment B₄C powder: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 1 μm；Ratio of grinding media to material For 100:1,280r/min is set by the ball milling speed of batch mixer, Ball-milling Time is 2 hours；

(2) weigh pure Al powder (purity 99.0wt.%) that a certain amount of granularity is 48 μm, Ti powder that granularity is 25 μm it is standby With；

(3) Ti powder and B are pressed₄C powder mass ratio is that 2.595:1 weighs Ti powder and it is expected that generates TiC-TiB₂Ceramic particle accounts for whole The 40wt.% of a reaction green compact；Mixing B after aluminium powder, titanium valve, ball milling are activated₄C powder is configured to 100g mixed-powder, The wherein additive amount of each component alloyed powder are as follows: Al alloyed powder: 60wt.%；Ti powder: 28.872wt.%；B₄C powder: 11.128wt.%；

(4) powder of prepared different component is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, The ZrO of 7mm, 11mm, 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, powder and The overall volume of zirconium oxide balls is no more than the 3/4 of tank body volume；Ball grinder is installed in planetary batch mixer, and batch mixer turns Speed is set as 50r/min, and the mixed uniformly time is for 24 hours；

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 70MPa Lower pressure maintaining 2min obtains a height of 40mm, diameter of phi 30, the cylindrical green compact that consistency is 65%.

B, it begins to warm up, heating speed is set as 45K/min；When temperature is increased to 573K, vacuum degassing 15min is carried out； When temperature is increased to 773K, 20min is kept the temperature, is consistent graphite jig temperature with cylindrical green compact temperature.

C, when temperature continuation is increased to 1200K with 50K/min, observe the pressure in vacuum sintering funace in respect of significant After variation, after air pressure is greater than 100Pa, 20min is kept the temperature, heating is then stopped.When temperature is down to 1053K, to cylindrical green compact Apply axial direction 60MPa pressure, keeps the pressure 6s of the application；The cylinder densified after reaction and through axial compressive force contains nanometer TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is cooled to room temperature in a vacuum with furnace.

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.45wt.%；Si:0.22wt.%；Mn:0.70wt.%；Cr:0.98wt.%；Al:0.021wt.%；In-situ nano two-phase The pre-dispersed intermediate alloy additional amount of grain are as follows: 0.25wt.%, wherein the nano TiC-TiB contained₂Total content are as follows: 0.10wt.%；Surplus is Fe.

A, the 40wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 1₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle are as follows: 0.25wt.%；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into not equal small of 1000~2000g Block is then placed in remelting in medium-frequency induction furnace burner hearth, and the pure Al slagging-off of 3~5g is added, taps at 1630 DEG C；Molten steel is injected into steel In-situ nano two-phase TiC-TiB in packet, in ladle₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, in ladle Method in-situ nano TiC particle is poured to be scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1500 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel.

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 230K per hour 1220K heat preservation；(soaking time: every 1 millimeter of casting thickness adds 30 minutes for two minutes) then cools to room temperature with the furnace.

B, ultra fine-grained process technique: sample is put into vacuum atmosphere oven and is heated with the heating speed of 150K per hour After to 900K keep the temperature (soaking time: 30 minutes), continue to heat, to 1273K after keep the temperature, (soaking time: casting thickness it is every 2 milli Rice one minute), oil is cold rapidly, quenching.

C, tempering process: sample is put into after being heated to 500K in vacuum atmosphere oven with the heating speed of 120K per hour and is protected Temperature, soaking time: 8 hours, cooling the micro ceramics particle strengthened steel of biphase in situ in air.

In this example, as Figure 1 and Figure 4, in the reinforcing steel, 40wt.% in-situ nano TiC-TiB₂Particle is pre-dispersed Intermediate alloy additional amount are as follows: 0.25wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.1wt.%；Two-phase pottery is added After porcelain particle, compared in un-added situation, the structure refinement of low-alloy steel is significant；By adding nanometer two-phase TiC-TiB₂ After ceramics particle strengthened, yield strength, tensile strength, breaking strain, the impact flexibility (U-shaped notch) of steel be respectively 1240MPa, 1459MPa, 8.4%, 18.6J/cm², respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/cm²) respectively Improve 22.8%, 31.4%, 20.0%, 10.7%.Intensity, plasticity and impact flexibility significantly improve；Obviously, it only carries out micro Addition, that is, obtain the significant reinforcing of strong plasticity.

Example IV

The method of the ceramics particle strengthened steel of the micro biphase in a kind of original position of this example, which is characterized in that including following step It is rapid:

(1) ball milling activating pretreatment B₄C powder: by B₄C powder is put into ball grinder, wherein B₄The granularity of C powder is 3 μm；Ratio of grinding media to material For 100:1,350r/min is set by the ball milling speed of batch mixer, Ball-milling Time is 3 hours；

(3) Ti powder and B are pressed₄C powder mass ratio is the B that 2.595:1 weighs Ti powder and mixes₄C powder；By aluminium powder, titanium valve, ball Mixing B after mill activation processing₄C powder is configured to 100g mixed-powder, wherein the additive amount of each component alloyed powder are as follows: Al alloy Powder: 70wt.%；Ti powder: 21.655wt.%；B₄C powder: 8.345wt.%；

(4) powder of prepared different component is put into ball grinder, be equipped in ball grinder diameter be respectively 5mm, The ZrO of 7mm, 11mm, 15mm, 20mm, 22mm₂Ball is 10 every kind, ZrO₂Ball quality total 800g, ratio of grinding media to material 8:1, powder and The overall volume of zirconium oxide balls is no more than the 3/4 of tank body volume；Ball grinder is installed in planetary batch mixer, and batch mixer turns Speed is set as 80r/min, and the mixed uniformly time is 48h；

(5) powder mixed in above-mentioned steps is wrapped up and sealed with thin aluminium foil, and the powder wrapped is placed in stainless steel mold In tool, a stainless steel column is equipped with above powder, hydraulic press room temperature applies lower with unidirectional axial compressive force, then in 90MPa Lower pressure maintaining 3min obtains a height of 45mm, diameter of phi 30, the cylindrical green compact that consistency is 70%.

C, when temperature continuation is increased to 1200K with 60K/min, the air pressure of the pressure gauge in vacuum sintering funace is observed After 100Pa, 30min is kept the temperature, heating is then stopped.When temperature is down to 1053K, cylindrical green compact is applied axial 75MPa pressure keeps the pressure 90s of the application；The cylinder densified after reaction and through axial compressive force contains nano TiC- TiB₂The pre-dispersed intermediate alloy of ceramic particle is cooled to room temperature in a vacuum with furnace.

Micro in-situ nano TiC-TiB₂The main chemical compositions of particle Strengthening and Toughening steel are by weight percentage: C: 0.50wt.%；Si:0.37wt.%；Mn:0.80wt.%；P:0.035wt.%；S:0.035wt.%；Cr:1.1wt.%；Ni: 0.25wt.%；Cu:0.25wt.%；The pre-dispersed intermediate alloy additional amount of Al:0.24wt.% in-situ nano diphase particles are as follows: 0.40wt.% the, wherein nano TiC-TiB contained₂Total content are as follows: 0.16wt.%；Surplus is Fe.

A, the 40wt.% in-situ nano two-phase TiC-TiB that will be prepared in step 1₂The pre-dispersed intermediate alloy cutting of particle It is cut into small pieces, chooses in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle are as follows: 0.4wt.%；

C, using 50Kg medium-frequency induction furnace, non-oxidizing process process for making.Steel is cut into not equal small of 1000~2000g Block is then placed in remelting in medium-frequency induction furnace burner hearth, and the pure Al slagging-off of 5g is added, taps at 1700 DEG C；Molten steel is injected into ladle It is interior, the in-situ nano two-phase TiC-TiB in ladle₂The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and rushes in ladle Enter method in-situ nano TiC particle to be scattered in molten steel；

D, the molten steel in ladle is at the uniform velocity poured at 1500 DEG C or so having a size of 40 (bottom) × 60 (upper bottom) × 180 The SiO of (height) × 300 (length) mm₂In sand mold, micro in-situ nano TiC-TiB is obtained₂Particle Strengthening and Toughening steel；

A, Homogenization Treatments technique: sample is put into vacuum atmosphere oven and is heated to the heating speed of 250K per hour 1250K heat preservation；(soaking time: casting thickness it is every 1 millimeter+30 minutes two minutes) then cool to room temperature with the furnace.

C, tempering process: sample is put into after being heated to 523K in vacuum atmosphere oven with the heating speed of 135K per hour and is protected Temperature, soaking time: 10 hours, cooling the micro ceramics particle strengthened steel of biphase in situ in air.

In this example, as shown in Figure 1, shown in Figure 5, in the reinforcing steel, 30wt.% in-situ nano TiC-TiB₂Particle is pre-dispersed Intermediate alloy additional amount are as follows: 0.40wt.%, wherein the nano TiC-TiB contained₂Content are as follows: 0.16wt.%；Two-phase is added After ceramic particle, compared in un-added situation, the structure refinement of low-alloy steel is obvious.By adding nanometer two-phase TiC- TiB₂After ceramics particle strengthened, yield strength, tensile strength, breaking strain, the impact flexibility (U-shaped notch) of steel are respectively 1420MPa, 1562MPa, 7.4%, 18.8J/cm², respectively than un-added steel (1010MPa, 1110MPa, 7.0%, 16.8J/ cm²) it has been respectively increased 40.6%, 40.7%, 8.6%, 11.9%.Intensity, plasticity and impact flexibility significantly improve；Obviously, only Micro addition is carried out, that is, obtains the significant reinforcing of strong plasticity.

In the present invention by four embodiments and a comparative example (being not added with nano particle in the comparative example), finally To reinforcing steel to measure its physical property as shown in Table 1 below, show only to carry out micro addition to nano particle, that is, obtain Strengthen the significant reinforcing of firm plasticity.

1 four embodiments of table and the performance for strengthening steel obtained in three comparative examples

A kind of key technology of the micro biphase ceramic particle enhancing steel obdurability in original position of the invention is within Raw two-phase TiC-TiB₂The pre-dispersed intermediate alloy of ceramic particle is nanoparticle vector, will be received by nano particle intermediate alloy Rice grain is brought into the melt of steel, since the nano particle of intermediate alloy is pre-dispersed, the nano particle in intermediate alloy It is separated by aluminum substrate, a large amount of nanoparticle agglomerates will not occur, the nano particle quilt after entering in molten steel, in intermediate alloy It is gradually released in molten steel, promotes the dispersion of nano particle.Mismatch is low between TiC ceramic particle and steel melt, interface cohesion Stablize, lower mismatch is conducive to improve the wetability of particle in the base, and particle is easy to realize half coherence between matrix Or almost symbiosis and epibiosis, such as: (100) crystal face and Fe~γ (110) crystal face, Fe~γ (111) crystal face and Fe~γ of TiC (100) the two-dimensional crystal lattice mismatch of crystal face is respectively 12.7%, 10.0% and 14.4%, therefore, TiC particle can be used as Fe~ The heterogeneous forming core core of γ phase for refining the solidified structure of steel, and utilizes grain number under the conditions of nanometer equal volume score Big advantage is measured, number of nuclei is greatly improved, is conducive to forming core thinning microstructure, and non-forming core and is not captured by solid liquid interface Nano particle is adsorbed on solid liquid interface forward position, hinders the growth of dendrite, achievees the purpose that control dendrite size.The group of the steel of refinement Knit the performance that can strengthen steel with the nano particle in crystal grain, the nano particle pinning intercrystalline strengthening of grain boundaries, due to nanometer Grain is different from the coefficient of expansion of steel, causes occur a large amount of dislocation near nano particle, realizes dislocation strengthening, strong by appealing Change mechanism has obtained significantly improving for the obdurability of unexpected effect and steel.By nano TiC ceramic particle as steel Tissue modulation agent and hardening agent can effectively realize the microstructure refinement and Strengthening and Toughening of steel.For opening for high-performance steel iron material Hair and toughening technology provide a new approaches and methods.With important practical application value.

Although the embodiments of the present invention have been disclosed as above, but its is not only in the description and the implementation listed With it can be fully applied to various fields suitable for the present invention, for those skilled in the art, can be easily Realize other modification, therefore without departing from the general concept defined in the claims and the equivalent scope, the present invention is simultaneously unlimited In specific details and legend shown and described herein.

Claims

1. a kind of ceramics particle strengthened steel of micro biphase in original position, which is characterized in that the micro biphase ceramics in original position The chemical composition and its mass percent of particle strengthening steel are as follows:

C:0.38~0.50wt.%；Si:0.17~0.37wt.%；Mn:0.50~0.80wt.%；P :≤0.035wt.%；S: ≤ 0.035wt.%；Cr:0.8~1.1wt.%；Ni :≤0.25wt.%；Cu :≤0.25wt.%；TiC-TiB₂: 0.009~ 0.16wt.%, Al:0.021wt.%~0.24wt.%, surplus Fe.

2. the ceramics particle strengthened steel of the micro biphase in original position according to claim 1, which is characterized in that

The biphase ceramic particle is TiC-TiB₂The in-situ nano two-phase TiC-TiB of 30~40wt.% of granule content₂? The pre-dispersed intermediate alloy of grain, and the in-situ nano two-phase TiC-TiB₂The additive amount of the pre-dispersed intermediate alloy of particle is 0.03 ~0.40wt.%.

3. a kind of method of the ceramics particle strengthened steel of micro biphase in original position, which comprises the following steps:

Step 2: the cylindrical green compact is reacted by in-situ sintering is made in-situ nano two-phase TiC-TiB₂During particle is pre-dispersed Between alloy；

Step 3: by the in-situ nano two-phase TiC-TiB₂The pre-dispersed intermediate alloy of particle is put into Ladle Bottom after being cut into fritter Then portion obtains micro in-situ nano TiC-TiB by non-oxidizing process process for making and casting process₂Particle Strengthening and Toughening steel；

Step 4: by the micro in-situ nano TiC-TiB₂It is super that particle Strengthening and Toughening steel successively carries out Homogenization Treatments technique, crystal grain Micronization processes technique and tempering process obtain the micro ceramics particle strengthened steel of biphase in situ.

4. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 3, which is characterized in that

The raw material B₄C powder passes through ball milling activating pretreatment；

The raw material aluminum powder particle size is 13~75 μm, purity 99.0wt.%；

The raw material titanium valve granularity is 13~48 μm.

5. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 4, which is characterized in that

Aluminium powder mass fraction is 60wt.% in the mixed-powder, and titanium valve mass fraction is 28.872wt.%, B₄C silty amount point Number is 11.128wt.%.

6. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 4, which is characterized in that

Aluminium powder mass fraction is 70wt.% in the mixed-powder, and titanium valve mass fraction is 21.655wt.%, B₄C silty amount point Number is 8.345wt.%.

7. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 5 or 6, which is characterized in that The step 2 specifically includes the following steps:

Step a, it is put into cylindrical graphite mold after wrapping up the cylindrical green compact with thin graphite paper, is placed at the top of green compact High-strength graphite compression bar, the position of fixed green compact in a mold, mold and graphite compression bar are integrally put into vacuum sintering funace, Furnace pressure is evacuated to lower than 0.001Pa；

Step b, it is heated with the speed that heating speed is 25~60K/min, when temperature is increased to 573K, carries out 10~20min Vacuum degassing；When temperature continues to be increased to 773K, 15~25min is kept the temperature；

Step c, continue to increase temperature with 30~60K/min of heating rate to 1173K~1200K, observe vacuum heating-press sintering After pressure in furnace is greater than 100Pa, stop heating after keeping the temperature 10~30min；When temperature is down to 1053K, to cylindrical green compact Apply axial 45~75MPa pressure, keeps 30~90s of pressure of the application；It is pre- that two-phase is obtained after being cooled to room temperature in a vacuum Disperse TiC-TiB₂Ceramic particle intermediate alloy.

8. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 7, which is characterized in that described In step 3,

Choose nanometer two-phase TiC-TiB₂Granule content is the in-situ nano two-phase TiC-TiB of 30~40wt.%₂Particle is pre-dispersed Intermediate alloy fritter, and the intermediate alloy content is 0.03wt.%~0.40wt.%.

9. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 8, which is characterized in that described In step 3, the non-oxidizing process steel-making is specifically included:

Steel is cut into the bulk of 1000~2000g, is then placed in the medium-frequency induction furnace burner hearth of 50Kg, 3~5g fine aluminium is added Slagging-off goes out molten steel at 1600~1700 DEG C of temperature；Molten steel is injected into ladle, the in-situ nano two-phase TiC-TiB in ladle₂ The pre-dispersed intermediate alloy of particle seethes with molten steel and is dispersed, and nano-TiC particle is poured in ladle and is scattered in molten steel；

The casting process specifically includes:

It is respectively go to the bottom 40mm, upper bottom 60mm, height that molten steel in ladle, which is at the uniform velocity poured into size at 1400~1500 DEG C or so, 180mm, the SiO of long 300mm₂In sand mold, micro two-phase TiC-TiB in situ is obtained₂Particle Strengthening and Toughening steel.

10. the method for the ceramics particle strengthened steel of the micro biphase in original position according to claim 9, which is characterized in that institute It states in step 4, the Homogenization Treatments technique includes:

It will micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel is put into vacuum atmosphere oven with the heating of 200~250K per hour Speed is heated to 1200~1250K, then homogenization heat preservation；Then micro two-phase in situ must be homogenized by cooling to room temperature with the furnace TiC-TiB₂Particle Strengthening and Toughening steel；

Wherein, the homogenization soaking time t₁Meet:

t₁=2h₁+30；

The ultra fine-grained process technique includes:

It will homogenization micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel is put into vacuum atmosphere oven with 100~180K per hour Heating speed be heated to 873K~923K, keep the temperature 20~40min, continue fine after being heated to 1223~1323K and keep the temperature, it is fast Fast oil is cold, quenches to obtain fine micro two-phase TiC-TiB in situ₂Particle Strengthening and Toughening steel；

Wherein, the fine soaking time t₂Meet:

t₂=h₂/2；

Wherein, h₂For homogenization micro two-phase TiC-TiB in situ₂The thickness of particle Strengthening and Toughening steel.