CN106148673A - A kind of high-carbon steel high-temperature heating diffusion control method - Google Patents

Abstract

The present invention relates to a kind of high-carbon steel high-temperature heating diffusion control method, described control method is according to the parameter information of steel billet, it is calculated initial temperature distribution and the initial carbon concentration distribution of steel billet, and according to described initial carbon concentration distribution and initial temperature distribution, by computer model, in dynamic calculation high temperature furnace, the Current Temperatures of steel billet is distributed and current carbon content distribution, thus more accurately determines the high-temperature heating diffusion end time of high-carbon steel carbon, guarantee product quality, save energy resource consumption.Solve the diffusion of existing high-carbon steel high-temperature heating and cannot accurately control the heat time, it is impossible to meet the problem that product quality requires and saves the energy simultaneously.

Description

A kind of high-carbon steel high-temperature heating diffusion control method

Technical field

The present invention relates to technical field of metallurgical production, particularly the processing and forming of hot-rolled steel, specifically a kind of High-carbon steel high-temperature heating spreads control method.

Background technology

The carbon component segregation of high-carbon steel is a technology difficulty being difficult to be fully solved by the steel-making continuous casting stage Topic, steel billet or steel ingot uneven chemical components, to machining, heat treatment, drawing stability and other Application performance brings adverse effect.At present, much high-grade steel need for being come by High temperature diffusion Mitigate or eliminate dendritic segregation.The conventional method using is: strand or steel ingot, be placed on heating In the middle of stove or soaking pit, then according to given process curve carries out heat temperature raising, insulation, thus real Existing High temperature diffusion.

Most important two parameters of high-temperature heating diffusion technique are heating-up temperature and temperature retention time.Regrettably, The formulation of current high-temperature diffusion process parameter, without reliable theoretical foundation, lacks effective normative reference. For steel ingot, the different supplied materials sizes etc. of different materials, high-temperature diffusion process parameter should have difference and Specific aim.But, existing technics comparing is general, is that examination is gathered by rule of thumb mostly, and the result causing is, In some cases, disclosure satisfy that quality requirement, but may be long due to temperature retention time so that crystal grain is excessively Thick and cause energy huge waste；And in some cases, owing to temperature retention time falls short of, it is impossible to reach The purpose of High temperature diffusion, consumes the energy of preciousness in vain.

It owing to high-temperature heating diffusion is under the high temperature more than 1200 degree, is incubated a few hours, energy-output ratio Very big, oxidization burning loss is also very serious.At present, steel and iron industry comes into low margin age, each iron and steel Enterprise all pays special attention to product quality and energy resource consumption.Needing the steel grade of High temperature diffusion, it is in heating process In energy resource consumption, account for whole production process energy total amount more than 80%, therefore, how most preferably The heating process of control High temperature diffusion, on the premise of ensureing product quality, reduces the consumption of fuel as far as possible Amount is very important.Heating process for Optimal Control High temperature diffusion, it is desirable to provide a kind of technology hand Section, according to different steel grades, different steel billet physical dimensions, dynamically judges the effect of High temperature diffusion, with Just the time that high-temperature heating diffusion terminates accurately is determined.

For the solution of this problem, domestic main patent and document are as follows:

" external metal heat treatmet " the 4th phase in 1998, " work in process deviation correction for the carbon diffusion model With " literary composition, carbon diffusion model being successfully used in the carburizing heat treatment of steel, application shows: this model ratio It is relatively suitable for Deep Carburization Process.But, in order to eliminate carbon segregation, high-carbon steel needs High temperature diffusion, this high temperature Physical process and carburizing are diverse, so, the method can not expand to high-carbon steel High temperature diffusion this The occasion of sample, needs a kind of new technological means.

Heating furnace Application Number (patent): CN200910012026.7；Denomination of invention: a kind of minimizing high-carbon The method of the internal carbon segregation of steel.A kind of method reducing carbon segregation in high-carbon steel of this disclosure of the invention.Invention The production technology using is: steel-making → refining → continuous casting → heating furnace heating → tandem rolling, it is characterised in that: During heating furnace heating, heat time≤1.5 hour, soaking time is >=2.0 hours, and total time is little for≤3.5 When, tapping temperature is 1150 DEG C～1250 DEG C, and start rolling temperature is 1100 DEG C～1250 DEG C, finishing temperature ≥900℃。

This patent only gives the scope of heat time, is not given according to steel grade, billet bloom size, dynamic The situation that in state calculating steel billet, carbon segregation is diffused with temperature, does not provide high-carbon steel High temperature diffusion knot yet The control method of bundle time.Therefore, it is also just difficult to the Optimal Control of high-carbon steel High temperature diffusion, also difficult To reach both to meet the requirement of product quality, save again the purpose of the energy.

Content of the invention

It is an object of the invention to provide a kind of high-carbon steel high-temperature heating diffusion control method, described controlling party Method is by the Temperature Distribution of steel billet in computer model dynamic calculation high temperature furnace and carbon content distribution, thus Determine the high-temperature heating diffusion end time of high-carbon steel carbon, it is ensured that product quality goodly, save energy resource consumption. Cannot accurately control the heat time in order to solve the diffusion of existing high-carbon steel high-temperature heating, it is impossible to meet simultaneously The problem that product quality requires and saves the energy.

For achieving the above object, the solution of the present invention is: a kind of high-carbon steel high-temperature heating diffusion control method, Described high-carbon steel high-temperature heating diffusion control method comprises the steps:

(1) set target temperature deviation and the aim carbon concentration deviation of steel billet, obtain the parameter information of steel billet, Calculate initial temperature distribution and the initial carbon concentration distribution of steel billet according to described parameter information；

(2) obtaining in-furnace temperature, the radiation coefficient in the physical parameter according to steel billet and high temperature furnace, with step Suddenly the initial temperature of the steel billet that (1) calculates is distributed as starting point, uses the equation of heat conduction, calculates working as of steel billet Front Temperature Distribution；

(3) the Current Temperatures distribution of the steel billet obtaining according to step (2), the steel calculating with step (1) The initial carbon concentration of base is distributed as starting point, according to Carbon diffusion activation energy and diffusion coefficient in steel billet, uses Diffusion equation, calculates the current carbon content distribution of steel billet；

(4) the Current Temperatures distribution according to described steel billet and carbon content distribution, calculate the maximum temperature of steel billet Deviation △ T_actWith maximum concentration of carbon deviation △ C_act, and the target temperature deviation △ T with setting_aimDense with aim carbon Degree deviation △ C_aimCompare, if △ is T_actLess than or equal to △ T_aim, and △ C_actLess than or equal to △ C_aim, Then the heating quality of steel billet meets technological requirement, and high-temperature heating diffusion terminates；Otherwise, according to step (1) Again calculate initial temperature distribution and the carbon content distribution of steel billet, again high-temperature heating diffusion is carried out to steel billet.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (1), Described steel billet parameter information include billet bloom size, steel billet thermal conductivity factor, steel billet specific heat, steel billet density, Carbon diffusion activation energy and diffusion coefficient.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (1), If calculating for the first time, then the initial temperature distribution of steel billet is set to the surface temperature of actual measurement during billet-charging Degree, it may be assumed thatThe steel of acquisition is checked in the initial carbon concentration distribution of steel billet before being set to billet-charging Base carbon content distribution, it may be assumed that

Otherwise, the initial temperature of steel billet is distributed as the last steel billet Current Temperatures distribution calculating and obtaining, it may be assumed thatThe initial carbon concentration of steel billet is distributed as the last current carbon content distribution of steel billet calculating and obtaining, That is: $C_i^{\mathrm{start}}=C_{\mathrm{old}}^i$

Wherein, T_sufThe surface temperature of measurement when being billet-charging；

It is the carbon content distribution checking acquisition before billet-charging；

Calculate the Current Temperatures distribution of the steel billet obtaining for the last time；

Calculate the current carbon content distribution of the steel billet obtaining for the last time；

I is the sequence number of steel billet thickness direction grid, and N is maximum mesh number.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (2), The Current Temperatures distribution of described steel billet, uses conventional difference method to calculate, solves the equation of heat conduction, heat The expression-form of diffusivity equation is as follows:

$\left\{\begin{array}{cc}\frac{\∂T}{\∂t}=a\·\frac{{\∂}^{2}T}{{\∂x}^2}& x\∈[x_1,x_N]\\ T(x,0)=T_i^{\mathrm{start}}& i\∈[1,N]\\ \mathrm{\λ}\·{\frac{\∂T}{\∂x}|}_{x=x_1}=-Q_{\mathrm{down}};& \mathrm{\λ}\·{\frac{\∂T}{\∂x}|}_{x=x_N}=Q_{\mathrm{top}};\end{array}\right.$

$Q_{\mathrm{top}}={\mathrm{\ϵ}}_{\mathrm{top}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{top}}+273}{100}\right)}^4-{\left(\frac{T_N+273}{100}\right)}^4],Q_{\mathrm{down}}={\mathrm{\ϵ}}_{\mathrm{down}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{down}}+273}{100}\right)}^4-{\left(\frac{T_1+273}{100}\right)}^4]$

Wherein, Q_topUpper surface hot-fluid for steel billet；

Q_downFor steel billet lower surface hot-fluid；

A is temperature diffusivity；

λ is thermal conductivity factor；

ε_top∈ (0,1) is high temperature furnace internal upper part radiation coefficient；

σ is Boltzmann constant；

For upper furnace temperature；

T_NFor steel billet upper surface temperature；

ε_down∈ (0,1) is lower radiant coefficient in high temperature furnace；

For upper furnace temperature；

T₁For steel billet underlaying surface temperature.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (3), The expression-form of described diffusion equation is as follows:

$\left\{\begin{array}{c}\frac{\∂C}{\∂t}=D\·\frac{{\∂}^{2}C}{{\∂x}^2}\\ C(x,0)=C_0\left(x\right)\end{array}\right.$

D=D₀exp(-Q/RT)

Wherein, D is diffusion coefficient；

Q is diffusion activation energy, and unit is J/mol；

R is gas constant；

The temperature of steel billet thickness direction each layer grid for being obtained by step 2 for the T；

D₀For diffusion constant；

C₀X () is the initial carbon concentration distribution of steel billet；

C (x, 0) is the current carbon content distribution of steel billet.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (4), Described maximum concentration of carbon deviation △ C_act, be obtain according to step (3) steel billet upper surface concentration of carbon, under Surface carbon concentration and center concentration of carbon, first obtain the absolute value of upper surface concentration of carbon and the difference of center concentration of carbon And the absolute value of the difference of lower surface concentration of carbon and center concentration of carbon, then by the maximum in two absolute values Value is as concentration of carbon deviation △ C_actThat is:

△C_act=max{ △ c₁,△c₂}

△c₁=| C_center-C₁|, △ c₂=| C_center-C_N|

Wherein, △ c₁The absolute value of difference for lower surface concentration of carbon and the center concentration of carbon of steel billet；

△c₂The absolute value of difference for upper surface concentration of carbon and the center concentration of carbon of steel billet；

C_center、C₁、C_NIt is respectively steel billet center concentration of carbon, lower surface concentration of carbon and upper surface concentration of carbon.

Spread control method according to high-carbon steel high-temperature heating of the present invention, in described step (4), Described maximum temperature deviation △ T_act, it is steel billet upper surface temperature, the lower surface obtaining according to step (2) Temperature and central temperature, first obtain the absolute value of upper surface temperature and the difference of central temperature, and under steel billet The absolute value of the difference of surface temperature and central temperature, then using the maximum of two absolute values as maximum temperature Degree deviation △ T_act, it may be assumed that

△T_act=max{ △ T₁,△T₂}

△T₁=| T_center-T₁|, △ T₂=| T_center-T_N|

Wherein, △ T₁The absolute value of difference for underlaying surface temperature and the central temperature of steel billet；△T₂For steel billet The absolute value of the difference of upper surface temperature and central temperature；T_center、T₁、T_NBe respectively steel billet central temperature, Underlaying surface temperature and upper surface temperature.

The beneficial effect that the present invention reaches: the control method of the present invention can realize expanding high-carbon steel high-temperature heating During Saning, Temperature Distribution, carbon content distribution are monitored over time, and according to temperature homogeneity Index and concentration of carbon uniformity index, be determined more accurately the end time of high-temperature heating diffusion.Pass through The Temperature Distribution of steel billet and carbon content distribution in computer model dynamic calculation high temperature furnace, thus most preferably true Determine the high-temperature heating diffusion end time of high-carbon steel carbon, it is ensured that product quality, save energy resource consumption.

Brief description

Fig. 1 is the control flow chart of the present invention；

Fig. 2 is that the network of the present invention divides schematic diagram；

Fig. 3 is the heating process heating curve schematic diagram of the present invention；

Fig. 4 is the carbon content distribution curve synoptic diagram of the present invention.

Detailed description of the invention

The present invention is further detailed explanation below in conjunction with the accompanying drawings.

As it is shown in figure 1, the detailed process of control method of the present invention is as follows:

Step 1, obtains the relevant parameter information of steel billet, according to described parameter information, calculates at the beginning of steel billet Beginning Temperature Distribution and carbon content distribution.

If calculating for the first time, then steel billet thickness direction is carried out at the beginning of equally spaced stress and strain model, steel billet The surface temperature of beginning Temperature Distribution actual measurement when being shove charge, it may be assumed thatThe initial carbon of steel billet is dense Degree is distributed as filling the steel billet carbon content distribution that foundry test obtains, it may be assumed that

Calculate if not first, then the initial temperature of steel billet is distributed as the last steel billet obtaining that calculates and works as Front Temperature Distribution, it may be assumed thatThe initial carbon concentration of steel billet is distributed as the last steel calculating and obtaining The current carbon content distribution of base, it may be assumed that

Wherein,Initial temperature distribution for steel billet；

T_sufThe surface temperature of measurement when being billet-charging；

Calculate the steel billet Current Temperatures distribution obtaining for the last time；

Calculate the current carbon content distribution of steel billet obtaining for the last time；

It is the initial carbon concentration distribution of steel billet；

It is the carbon content distribution checking acquisition before billet-charging；

I is the sequence number of steel billet thickness direction grid, i=1, and 2,3.....N, N are maximum mesh numbers, stress and strain model Schematic diagram see Fig. 2, along steel billet thickness direction, start to upper surface from steel billet lower surface, by steel billet thickness Being divided into i=1,2,3...N layers, i=1 is ground floor i.e. lower surface, and i=N is last layer, i.e. upper surface.

Step 2, obtains in-furnace temperature, the physical parameter according to steel billet and radiation coefficient, obtains with step 1 The initial temperature of steel billet be distributed as starting point, use the equation of heat conduction, calculate the Current Temperatures distribution of steel billet.

The expression-form of the described equation of heat conduction is as follows:

$\left\{\begin{array}{cc}\frac{\∂T}{\∂t}=a\·\frac{{\∂}^{2}T}{{\∂x}^2}& x\∈[x_1,x_N]\\ T(x,0)=T_i^{\mathrm{start}}& i\∈[1,N]\\ \mathrm{\λ}\·{\frac{\∂T}{\∂x}|}_{x=x_1}=-Q_{\mathrm{down}};& \mathrm{\λ}\·{\frac{\∂T}{\∂x}|}_{x=x_N}=Q_{\mathrm{top}};\end{array}\right.$

$Q_{\mathrm{top}}={\mathrm{\ϵ}}_{\mathrm{top}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{top}}+273}{100}\right)}^4-{\left(\frac{T_N+273}{100}\right)}^4],Q_{\mathrm{down}}={\mathrm{\ϵ}}_{\mathrm{down}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{down}}+273}{100}\right)}^4-{\left(\frac{T_1+273}{100}\right)}^4]$

Wherein, Q_topUpper surface hot-fluid for steel billet；

Q_downFor steel billet lower surface hot-fluid；

A is temperature diffusivity；

λ is thermal conductivity factor；

ε_top∈ (0,1) is high temperature furnace internal upper part radiation coefficient；

σ is Boltzmann constant；

For upper furnace temperature；

T_NFor steel billet upper surface temperature；

ε_down∈ (0,1) is lower radiant coefficient in high temperature furnace；

For upper furnace temperature；

T₁For steel billet underlaying surface temperature.

Step 3, according to the result of calculation of step 2, with the initial carbon concentration distribution of the steel billet that step 1 obtains For starting point, the diffusion activation energy according to steel billet and diffusion coefficient, use diffusion equation, calculate working as of steel billet Front carbon content distribution.

The expression-form of described diffusion equation is as follows:

$\left\{\begin{array}{c}\frac{\∂C}{\∂t}=D\·\frac{{\∂}^{2}C}{{\∂x}^2}\\ C(x,0)=C_0\left(x\right)\end{array}\right.$

D=D₀exp(-Q/RT)

Wherein, D is diffusion coefficient；Q is diffusion activation energy, and unit is J/mol；R is gas constant； D₀For diffusion constant；The temperature of steel billet thickness direction each layer grid for being obtained by step 2 for the T；C₀(x) Initial carbon concentration distribution for steel billet；C (x, 0) is the current carbon content distribution of steel billet.

Step 4, the result of calculation obtaining according to step 2 and step 3, calculate the maximum temperature deviation of steel billet △T_actWith maximum concentration of carbon deviation △ C_act, and by calculated maximum temperature deviation △ T_actDense with maximum carbon Degree deviation △ C_actWith the target temperature deviation △ T setting_aimWith aim carbon concentration deviation △ C_aimCompare, as Really △ T_actLess than or equal to △ T_aim, and △ C_actLess than or equal to △ C_aim, then the heating quality of steel billet, meets work Skill requires, High temperature diffusion terminates；Otherwise, step 1 is continued executing with.

The maximum temperature deviation △ T of described steel billet_act, be according to step 2 obtain steel billet upper surface, under Surface and central temperature, first obtain the absolute value of the upper surface temperature of steel billet and the difference of central temperature, and The underlaying surface temperature of steel billet and the absolute value of the difference of central temperature, then obtain the maximum of two absolute values Maximum temperature deviation △ T as steel billet_act, expression formula is:

△T_act=max{ △ T₁,△T₂}

△T₁=| T_center-T₁|, △ T₂=| T_center-T_N|

Wherein, T_center、T₁、T_NIt is respectively step 2 and calculate steel billet central temperature, the lower surface temperature obtaining Degree and upper surface temperature.

Described maximum concentration of carbon deviation △ C_act, be according to step 3 obtain steel billet upper surface, under Surface and center concentration of carbon, first obtain the absolute value of upper surface concentration of carbon and the difference of center concentration of carbon, and Lower surface concentration of carbon and the absolute value of the difference of center concentration of carbon, then obtain the maximum in two absolute values Maximum concentration of carbon deviation △ C as steel billet_act, expression formula is:

△C_act=max{ △ c₁,△c₂}

△c₁=| C_center-C₁|, △ c₂=| C_center-C_N|

Wherein C_center、C₁、C_NThe center concentration of carbon, the lower surface carbon that calculate the steel billet of acquisition for step 3 are dense Degree and upper surface concentration of carbon.

By technical scheme, just can realize dividing temperature in high-carbon steel high-temperature heating diffusion process Cloth, carbon content distribution are monitored over time, then, dense according to temperature homogeneity index and carbon Degree uniformity index, determines the end time that high-temperature heating spreads.High by computer model dynamic calculation The Temperature Distribution of steel billet and carbon content distribution in temperature stove, thus it is best determined by the high-temperature heating of high-carbon steel carbon The diffusion end time, it is ensured that product quality, save energy resource consumption.

Embodiment:

Below as a example by Gr15 bearing steel, steel billet thickness 300mm, the controlling party of the present invention is discussed in detail Method, Gr15 bearing steel steel billet enters soaking pit and carries out high-temperature heating diffusion, meets technological temperature requirement and expansion After dissipating quality requirement, terminating heating, carrying out rolling of coming out of the stove, specific implementation process is as follows:

It according to the control method of the present invention, is first according to step 1, obtain the relevant parameter information of steel billet, meter Calculate initial temperature distribution and the initial carbon concentration distribution of steel billet.

Steel billet thickness is 300mm, and for calculating for the first time, the initial temperature of steel billet is distributed when being set to shove charge The surface temperature of actual measurementI=1,2,3,4,5；The carbon content distribution of steel billet is set to The steel billet carbon content distribution of acquisition is checked before billet-chargingWherein $C_{\mathrm{act}}^2=1.07,$ $C_{\mathrm{act}}^3=1.2,$ $C_{\mathrm{act}}^4=1.0,$ $C_{\mathrm{act}}^5=0.93,$ Require that heating technique meets steel billet section The temperature difference is within 10 DEG C, within section carbon solubility deviation 0.05.

It is as follows that high-temperature heating diffusion heating-up temperature in stove changes over situation:

Technical process	800 DEG C of insulations	At the uniform velocity heat up	1100 DEG C of insulations	At the uniform velocity heat up	1240 DEG C of insulations
						Time h	3	2	2	1.5	>=2

For non-first time calculated case, I=1,2,3,4,5.Wherein T_sufIt is The surface temperature of measurement during billet-charging；It is the carbon content distribution checking acquisition before billet-charging. The Current Temperatures being respectively the steel billet that the last time calculates acquisition is distributed and current carbon content distribution；I is steel The sequence number of base thickness direction grid, N=5 is maximum mesh number, and Fig. 2 is shown in by the schematic diagram of stress and strain model.

According to step 2, obtain the temperature of thermocouple in high temperature furnace, in this example not in the same time electric thermo-couple temperature and The technological temperature in corresponding moment is identical, and the physical parameter according to steel billet and radiation coefficient take steel billet here The radiation coefficient ε on upper and lower surface_top、ε_downIt is respectively the 0.85th, 0.65.With at the beginning of the steel billet that step 1 is given Beginning Temperature Distribution is starting point, uses the equation of heat conduction, calculates the Current Temperatures distribution of steel billet.Described calculating The Temperature Distribution of steel billet, uses conventional difference method, the equation of heat conduction described in solution procedure 2.Add Thermal process heating curve is as shown in Figure 3.

According to step 3, the Current Temperatures distribution calculating being inputted as the temperature of diffusion coefficient, present case takes Diffusion constant is 0.13cm²/ s, diffusion activation energy is 34884cal/mol, and the steel billet being given with step 1 Current carbon content distribution be starting point, the diffusion activation energy according to steel billet and diffusion coefficient, use diffused sheet Journey, calculates the current carbon content distribution of steel billet.The current carbon content distribution of described calculating steel billet, often uses The difference method of rule, solves the diffusion equation that step 3 of the present invention provides.The final meter of carbon content distribution Calculate result as shown in Figure 4.

It according to step 4, is distributed according to calculated current carbon content distribution and Current Temperatures, calculates steel billet Maximum temperature deviation △ T_actWith the concentration of carbon deviation △ C calculating maximum_act, and the target given with technique Temperature deviation △ T_aim=10 and concentration of carbon deviation △ C_aim=0.05 compares, if △ is T_actIt is less than or equal to △T_aim, and △ C_actLess than or equal to △ C_aim, then the heating quality of steel billet, meet technological requirement, high temperature expands Dissipating bind bundle；Otherwise, step 1 is re-executed.

According to the final calculation result of Fig. 3 and Fig. 4, when heating process time 550min, △ T_act≤10； When heating process time 600min, △ C_act≤0.05.Therefore, when heating process time 600min, Meet △ T_actLess than or equal to △ T_aim, and △ C_actLess than or equal to △ C_aim；It is therefore possible to control steel billet high temperature Diffusion heating process terminates, and carries out steel rolling.

According to the inventive method, can realize to Temperature Distribution, carbon in high-carbon steel high-temperature heating diffusion process dense Degree distribution is monitored, over time then, according to temperature homogeneity index and concentration of carbon uniformity Index, determines the end time that high-temperature heating spreads.By steel in computer model dynamic calculation high temperature furnace The Temperature Distribution of base and carbon content distribution, thus it is best determined by the high-temperature heating end time of high-carbon steel carbon, Guarantee product quality, save energy resource consumption.

Claims (7)

1. a high-carbon steel high-temperature heating diffusion control method, it is characterised in that described high-carbon steel high temperature adds Thermal diffusion control method comprises the steps:

(1) set target temperature deviation and the aim carbon concentration deviation of steel billet, obtain the parameter information of steel billet, Calculate initial temperature distribution and the initial carbon concentration distribution of steel billet according to described parameter information；

(2) obtaining in-furnace temperature, the radiation coefficient in the physical parameter according to steel billet and high temperature furnace, with step Suddenly the initial temperature of the steel billet that (1) calculates is distributed as starting point, uses the equation of heat conduction, calculates working as of steel billet Front Temperature Distribution；

(3) the Current Temperatures distribution of the steel billet obtaining according to step (2), the steel calculating with step (1) The initial carbon concentration of base is distributed as starting point, according to Carbon diffusion activation energy and diffusion coefficient in steel billet, uses Diffusion equation, calculates the current carbon content distribution of steel billet；

(4) the Current Temperatures distribution according to described steel billet and carbon content distribution, calculate the maximum temperature of steel billet Deviation delta T_actWith maximum concentration of carbon deviation delta C_act, and target temperature deviation delta T with setting_aimDense with aim carbon Degree deviation delta C_aimCompare, if Δ T_actLess than or equal to Δ T_aim, and Δ C_actLess than or equal to Δ C_aim, Then the heating quality of steel billet meets technological requirement, and high-temperature heating diffusion terminates；Otherwise, according to step (1) Again calculate initial temperature distribution and the carbon content distribution of steel billet, again high-temperature heating diffusion is carried out to steel billet.

2. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (1), described steel billet parameter information includes billet bloom size, steel billet thermal conductivity factor, steel Base specific heat, steel billet density, Carbon diffusion activation energy and diffusion coefficient.

3. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (1), if calculating for the first time, then equally spaced grid is carried out to steel billet thickness direction Divide, and the surface temperature of measurement actual during billet-charging be distributed as the initial temperature of steel billet, it may be assumed thatThe steel billet concentration of carbon checking acquisition before billet-charging is distributed as the initial carbon concentration of steel billet, That is: $C_i^{\mathrm{start}}=C_{\mathrm{act}}^i;$

Otherwise, the initial temperature of steel billet is distributed as the last steel billet Current Temperatures distribution calculating and obtaining, it may be assumed thatThe initial carbon concentration of steel billet is distributed as the last current carbon content distribution of steel billet calculating and obtaining, That is: $C_i^{\mathrm{start}}=C_{\mathrm{old}}^i;$

Wherein, T_sufThe surface temperature of measurement when being billet-charging；

It is the carbon content distribution checking acquisition before billet-charging；

Calculate the Current Temperatures distribution of the steel billet obtaining for the last time；

Calculate the current carbon content distribution of the steel billet obtaining for the last time；

I is the sequence number of steel billet thickness direction grid, and N is maximum mesh number.

4. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (2), the expression-form of the described equation of heat conduction is as follows:

$\left\{\begin{array}{cc}\frac{\∂T}{\∂t}=a\·\frac{{\∂}^{2}T}{\∂x^2}& x\∈[x_1,x_N]\\ T(x,0)=T_i^{\mathrm{start}}& i\∈[1,N]\\ \mathrm{\λ}\·\frac{\∂T}{\∂x}{|}_{x=x_1}=-Q_{\mathrm{down}};& \mathrm{\λ}\·\frac{\∂T}{\∂x}{|}_{x=x_N}=Q_{\mathrm{top}};\end{array}\right.$

$Q_{\mathrm{top}}={\mathrm{\ϵ}}_{\mathrm{top}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{top}}+273}{100}\right)}^4-{\left(\frac{T_N+273}{100}\right)}^4],Q_{\mathrm{down}}={\mathrm{\ϵ}}_{\mathrm{down}}\mathrm{\σ}[{\left(\frac{T_{\mathrm{air}}^{\mathrm{down}}+273}{100}\right)}^4-{\left(\frac{T_1+273}{100}\right)}^4]$

Wherein, Q_topUpper surface hot-fluid for steel billet；

Q_downFor steel billet lower surface hot-fluid；

A is temperature diffusivity；

λ is thermal conductivity factor；

ε_top∈ (0,1) is high temperature furnace internal upper part radiation coefficient；

σ is Boltzmann constant；

For upper furnace temperature；

T_NFor steel billet upper surface temperature；

ε_down∈ (0,1) is lower radiant coefficient in high temperature furnace；

For upper furnace temperature；

T₁For steel billet underlaying surface temperature.

5. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (3), the expression-form of described diffusion equation is as follows:

$\left\{\begin{array}{c}\frac{\∂C}{\∂t}=D\·\frac{{\∂}^{2}C}{\∂x^2}\\ C(x,0)=C_0\left(x\right)\end{array}\right.$

D=D₀exp(-Q/RT)

Wherein, D is diffusion coefficient；

Q is diffusion activation energy, and unit is J/mol；

R is gas constant；

The temperature of steel billet thickness direction each layer grid for being obtained by step 2 for the T；

D₀For diffusion constant；

C₀X () is the initial carbon concentration distribution of steel billet；

C (x, 0) is the current carbon content distribution of steel billet.

6. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (4), described maximum concentration of carbon deviation delta C_act, obtain according to step (3) Steel billet upper surface concentration of carbon, lower surface concentration of carbon and center concentration of carbon, first obtain upper surface concentration of carbon with in The absolute value of the difference of the absolute value of the difference of heart concentration of carbon and lower surface concentration of carbon and center concentration of carbon, then Using the maximum in two absolute values as maximum concentration of carbon deviation delta C_act, expression formula is:

ΔC_act=max{ Δ c₁,Δc₂}

Δc₁=| C_center-C₁|, Δ c₂=| C_center-C_N|

Wherein, Δ c₁The absolute value of difference for lower surface concentration of carbon and the center concentration of carbon of steel billet；

Δc₂The absolute value of difference for upper surface concentration of carbon and the center concentration of carbon of steel billet；

C_center、C₁、C_NIt is respectively steel billet center concentration of carbon, lower surface concentration of carbon and upper surface concentration of carbon.

7. high-carbon steel high-temperature heating according to claim 1 diffusion control method, it is characterised in that In described step (4), described maximum temperature deviation delta T_act, it is the steel obtaining according to step (2) Base upper surface temperature, underlaying surface temperature and central temperature, first obtain the difference of upper surface temperature and central temperature Absolute value, and the absolute value of the difference of steel billet underlaying surface temperature and central temperature, then by two definitely The maximum of value is as maximum temperature deviation delta T_act, expression formula is:

ΔT_act=max{ Δ T₁,ΔT₂}

ΔT₁=| T_center-T₁|, Δ T₂=| T_center-T_N|

Wherein, Δ T₁The absolute value of difference for underlaying surface temperature and the central temperature of steel billet；

ΔT₂The absolute value of difference for upper surface temperature and the central temperature of steel billet；

T_center、T₁、T_NIt is respectively central temperature, underlaying surface temperature and the upper surface temperature of steel billet.