CN103551437B - A kind of hundred meters of high speed heavy rail production methods of microstress - Google Patents

Abstract

The invention provides a kind of hundred meters of high speed heavy rail production methods of microstress, including: temperature control step, temperature when rail arrives cold bed controls in preset temperature section T₁In；Pre-bending step, will arrive cold bed and temperature in preset temperature section T₁Interior rail carries out pre-bending process；Straightening step, before rectifying, temperature controls in preset temperature section T₂In, and the rail after pre-bending processes is carried out straightening processing.Present invention achieves and do not increasing in the case of extras do not carry out heat treatment, processed by pre-bending and straightening processing makes in the case of hundred meters of steel rail straightness meet " rail for high-speed railway " TB/T3276 standard-required, residual stress ensures within 100MPa, the residual stress that final realization is less, improves the safety coefficient of train operation greatly；Also reduce production cost simultaneously, add the added value of rail, improve the market competitiveness of rail.

Description

A kind of hundred meters of high speed heavy rail production methods of microstress

Technical field

The invention belongs to metal working technical area, particularly to a kind of hundred meters of high speed heavy rail production methods of microstress.

Background technology

It is known that steel hot rolling or welding after the inhomogeneous cooling of its section, steel tissue undergoes phase transition, steel receive The cold working such as aligning, can be caused residual stress by External Force Acting；Change caused residual stress and crystal grain the most in a organized way Between microstress also can cause residual stress.In steel, the existence of residual stress is the most tired to the serviceability of steel Performance has a great impact, if residual stress is crossed conference and directly affected high-speed railway traffic safety in rail.

Summary of the invention

The technical problem to be solved is to provide a kind of being capable of during Rail Production and reduces in rail Hundred meters of high speed heavy rail production methods of the microstress of residual stress.

For solving above-mentioned technical problem, the invention provides a kind of hundred meters of high speed heavy rail production methods of microstress, including: temperature Control step, temperature when rail arrives cold bed controls in preset temperature section T₁In；Pre-bending step, uses ANSYS finite element mould Intend analyzing the variations in temperature of rail cooling procedure；Rail pre-bending amount is set according to sunykatuib analysis result；According to described pre-bending amount system Determine pre-bending curve, and formulate the traveling distance being used for that rail is carried out the pre-bending dolly of pre-bending process according to described pre-bending curve； Traveling distance according to being formulated carries out pre-bending process by pre-bending dolly to rail；Straightening step, before rectifying, temperature controls Preset temperature section T₂In, and put in order by horizontal roller drafts, horizontal roller in setting equipment for straightening respectively, edger roll drafts And edger roll puts in order and the rail after pre-bending processes is carried out straightening processing.

Further, set rail pre-bending amount according to sunykatuib analysis result to include: described rail interlude pre-bending amount sets Unanimously, being gradually increased when described rail front end pre-bending amount is at pre-bending dolly, described rail rear end pre-bending amount is at pre-bending dolly Time be gradually reduced.

Further, described according to sunykatuib analysis result setting rail pre-bending amount；Prebuckling is formulated according to described pre-bending amount Line, and include for the traveling distance that rail is carried out the pre-bending dolly of pre-bending process according to the formulation of described pre-bending curve:

Stroke according to equation below setting pre-bending dolly and rail pre-bending amount:

$\left\{\begin{array}{cc}y=-7.77\&times;{10}^{-5}{x}^3+8.39\&times;{10}^{-4}{x}^2+0.14x-0.30& 0\&le;x\&le;28.8\\ y=2.5& 28.8<x<80\\ y=-3.23\&times;{10}^{-4}{x}^3+0.08x^2-6.75x+191.50& 80\&le;x\&le;103\end{array}\right.$

Wherein, x is rail length；Y is rail pre-bending amount.

Further, described rail after pre-bending processes is carried out straightening processing includes: by some in equipment for straightening Individual horizontal roller reduction settings is between 0mm-25mm, and drafts is subtracted successively by the horizontally arranged order of horizontal roller several described Little.

Further, described by several horizontal roller reduction settings between 0mm-25mm, drafts press several institutes State the horizontally arranged order of horizontal roller to be sequentially reduced and specifically include: build rail profile simplified model and rail tensile stress changing pattern Type；Send out when calculating described rail level aligning respectively according to described rail profile simplified model and rail tensile stress variation model The pure resilient bending moment of raw pure elastic bending, the elasto bending moment of generation elasto bending；Curved according to described pure elasticity Described in bent moment, described elasto bending torque setting, several horizontal roller drafts are between 0mm-25mm, if drafts is pressed A dry horizontally arranged order of described horizontal roller is sequentially reduced.

Further, described rail after pre-bending processes is carried out straightening processing includes: by some in equipment for straightening Individual edger roll displacement is set between 1mm-18mm, and displacement is sequentially reduced by the horizontally arranged order of edger roll several described.

Further, described being set between 1mm-18mm by several edger roll displacements in equipment for straightening, displacement is pressed Several horizontally arranged orders of described edger roll are sequentially reduced and specifically include: build rail profile simplified model and rail tensile stress Variation model；Calculate described rail edger roll respectively according to described rail profile simplified model and rail tensile stress variation model to rectify There is the pure resilient bending moment of pure elastic bending time straight, the elasto bending moment of elasto bending occurs；According to described pure Described in resilient bending moment, described elasto bending torque setting, several edger roll displacements are between 1mm-18mm, displacement It is sequentially reduced by the horizontally arranged order of edger roll several described.

Further, described preset temperature section T₁It is: 800 DEG C-900 DEG C；And/or, described preset temperature section T₂It is: 0 DEG C- 60℃。

Further, the expression formula of described rail tensile stress variation model is: as ε ＜ ε_sTime, σ=E* ε；As ε >=ε_s Time, σ=σ_S+E₁*(ε-ε_s)；Wherein, σ is rail yield strength；σ_SIt it is the rail yield strength limit；ε is strain；ε_sIt is that surrender should Become；E is elastic modelling quantity, E₁For Young's modulus.

The present invention provide hundred meters of high speed heavy rail production methods of a kind of microstress, by by temperature in preset temperature section T₁In Rail carry out pre-bending process；And temperature is controlled in preset temperature section T₂Rail after interior and pre-bending processes is carried out at aligning Reason；Achieve and do not increasing in the case of extras do not carry out heat treatment, processed by pre-bending and straightening processing makes In the case of hundred meters of steel rail straightness meet " rail for high-speed railway " TB/T 3276 standard-required, residual stress ensures Within 100MPa.The less residual stress of final realization improves the safety coefficient of train operation greatly；Also reduce life simultaneously Produce cost, add the added value of rail, improve the market competitiveness of rail.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to institute in embodiment The accompanying drawing used is needed to be briefly described, it should be apparent that, the accompanying drawing in describing below is only some enforcements of the present invention Example, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to obtains according to these accompanying drawings Obtain other accompanying drawing.

Hundred meters of high speed heavy rail production method process charts of microstress that Fig. 1 provides for the embodiment of the present invention；And

The technological process of pre-bending step in hundred meters of high speed heavy rail production methods of microstress that Fig. 2 provides for the embodiment of the present invention Figure；And

Fig. 3 carries out the some processes flow chart during horizontal straightening processing for the rail that the embodiment of the present invention provides；With And

Fig. 4 carries out the some processes flow chart during edger roll straightening processing for the rail that the embodiment of the present invention provides；With And

The ANSYS FEM (finite element) model schematic diagram that Fig. 5 provides for the embodiment of the present invention；And

The ANSYS hot analysis mode result that Fig. 6 provides for the embodiment of the present invention contrasts schematic diagram with actual measured results；With And

The pre-bending curve synoptic diagram that Fig. 7 provides for the embodiment of the present invention；And

The rail profile simplified model schematic diagram that Fig. 8 provides for the embodiment of the present invention；And

The pure elastic bending stress schematic illustration of strain that Fig. 9 provides for the embodiment of the present invention；And

The elasto bending ess-strain schematic diagram that Figure 10 provides for the embodiment of the present invention；And

The bilinear pairings material stress strain model schematic diagram that Figure 11 provides for the embodiment of the present invention；And

Figure 12 only penetrates into the partial cut-away schematic diagram of rail head for the plastic strain that the embodiment of the present invention provides；And

Figure 13 penetrates into the partial cut-away schematic diagram of rail head and the flange of rail for the plastic strain that the embodiment of the present invention provides；And

Figure 14 penetrates into the tunneling boring of rail head and the flange of rail for the plastic strain that the embodiment of the present invention provides, and is connected with the flange of rail The part web of the rail section at place produces the structural representation of plastic strain；And

Figure 15 penetrates into the tunneling boring of rail head and the flange of rail for the plastic strain that the embodiment of the present invention provides, and with rail head and rail The part web of the rail section of junction, the end produces the structural representation of plastic strain；And

The horizontal straightening process schematic diagram that Figure 16 provides for the embodiment of the present invention；And

The edger roll straightening process schematic diagram that Figure 17 provides for the embodiment of the present invention.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Describe, it is clear that described embodiment is only a part of embodiment of the present invention rather than whole embodiments wholely.Based on Embodiment in the present invention, the every other embodiment that those of ordinary skill in the art are obtained, broadly fall into present invention protection Scope.

It is known that hundred meters of rail are after air cooling, owing to rail profile each position Metal Distribution is different, so cooling speed Degree and contraction are also different, furthermore metal also can cause change in volume from austenite to perlitic transformation, all can cause deflection of rail. Owing to rail's end portion metal is bigger than bottom metal proportion, under equal cooling condition, flange of rail rate of cooling is very fast, and rail head Rate of cooling is relatively slow, and when the flange of rail is cooled to no longer produce contraction distortion, the temperature of rail head is the highest, relays in cooling procedure Continuous generation contraction distortion, therefore, after rail head cools down completely, whole heavy rail will bend to rail head, and this flexibility is before rectifying Flexibility.Bending rail cannot be processed, and also cannot use, so finished product rail must be delivered goods with straightened condition, reach straight State is necessary for aligning rail, and when deflection of rail is spent big, straightening deformation certainly will be excessive, and result can produce bigger Residual stress, even rectifys disconnected.Based on above-mentioned analysis, in order to reduce the residual stress after aligning, the embodiment of the present invention provide one Plant hundred meters of high speed heavy rail production methods of microstress, refer to Fig. 1, including:

S101: temperature control step, temperature when rail arrives cold bed controls in preset temperature section T₁In；

Specifically, owing to the too low steel rail spring of temperature is excessive during actual job, then pre-bending it is difficult to；Temperature is too high, Rail Surface hardness is relatively low, then easy galled spots during pre-bending；In order to ensure that rail in abundant pre-bending and does not affect it Ensure in the case of quality that rail, more than austenitizing temperature, can be arrived temperature control during cold bed by rail arrival cold bed temperature System is in preset temperature section T₁In；Preferably, preset temperature section T₁It it is 800 DEG C-900 DEG C.

S102: pre-bending step, uses the variations in temperature of ANSYS FEM Simulation rail cooling procedure；According to simulation Analysis result sets rail pre-bending amount；Formulate pre-bending curve according to described pre-bending amount, and be used for according to the formulation of described pre-bending curve Rail is carried out the traveling distance of the pre-bending dolly of pre-bending process；According to the traveling distance formulated by pre-bending dolly to rail Carry out pre-bending process；

Wherein, rail is special-shaped section shaped steel, and the area of dissipation of section each several part differs relatively big with the ratio of volume, cooling speed Degree difference is very big, thus causes the uneven distribution of temperature on heavy rail section, causes the amount of contraction of heavy rail section each several part to differ Sample, produces thermal stress and hot bending square.Namely above-mentioned analysis theories is under equal cooling condition, flange of rail rate of cooling is very fast, and rail Head rate of cooling is relatively slow, and when the flange of rail is cooled to no longer produce contraction distortion, the temperature of rail head is the highest, in cooling procedure Continuing to produce contraction distortion, therefore, after rail head cools down completely, whole heavy rail will bend to rail head, and this flexibility is strong Antecurvature curvature.In order to reduce strong antecurvature curvature, need to carry out pre-bending before rectifying, simultaneously for rational prebending process, can press Operate according to following concrete steps:

Use the variations in temperature 201 of ANSYS FEM Simulation rail cooling procedure；Set according to sunykatuib analysis result Rail pre-bending amount 202；Formulate pre-bending curve according to described pre-bending amount, and formulate for rail is carried out according to described pre-bending curve The traveling distance 203 of the pre-bending dolly that pre-bending processes；Rail is carried out pre-by pre-bending dolly by the traveling distance according to being formulated Crook reason 204.

In the present embodiment, ANSYS finite element (Fig. 5 is FEM (finite element) model) is used to analyze cooling procedure variations in temperature, by Fig. 6 Visible ANSYS heat analyzes the analog result to heavy rail cooling temperature field, the most identical with actual measured results.Cold according to rail But curve, due to the friction between rail and cold bed and by head, the restraining function of two sections of rail self of tail, after interlude cooling Bending less, i.e. rail interlude pre-bending amount can be set to unanimously, keep rail interlude straight；And adopt during the pre-bending of rail front end With curve, the pre-bending amount at pre-bending dolly is gradually increased, and is gradually reduced when described rail rear end pre-bending amount is at pre-bending dolly, And formulate pre-bending curve as shown in Figure 7, according to pre-bending curve with a length of X-axis of rail, pre-bending amount is Y-axis, and curve can divide It it is three sections.End to end two sections of curves are fitted respectively, obtain following pre-bending curvilinear equation and final according to pre-bending curvilinear equation The stroke of formulation pre-bending dolly:

$\left\{\begin{array}{cc}y=-7.77\&times;{10}^{-5}{x}^3+8.39\&times;{10}^{-4}{x}^2+0.14x-0.30& 0\&le;x\&le;28.8\\ y=2.5& 28.8<x<80\\ y=-3.23\&times;{10}^{-4}{x}^3+0.08x^2-6.75x+191.50& 80\&le;x\&le;103\end{array}\right.$

S103: straightening step, before rectifying, temperature controls in preset temperature section T₂In, and by setting in equipment for straightening respectively Horizontal roller drafts, horizontal roller put in order, edger roll drafts and edger roll put in order to the rail after pre-bending processes Carry out straightening processing；

Wherein, owing to rail is high-carbon steel, in order to ensure its leveling effect, utilize rail in bigger elasto bending condition Under, no matter its original curved degree has much differences, and the degree of crook difference remained after spring-go can be substantially reduced, and even can Reach unanimity；Along with the reduction of press-bending degree, the residual bending after its spring-go unanimously will necessarily tend to null value and reach to align mesh , just because of being subject to bigger power during steel rail straightening, so straightening temperature is difficult to too high, therefore, before rectifying, temperature controls Preset temperature section T₂In；Preferably, preset temperature section T₂It is: 0 DEG C-60 DEG C.

In the present embodiment, the rail after pre-bending processes is carried out straightening processing and includes: several horizontal roller are depressed Amount is set between 0mm-25mm, and drafts is sequentially reduced by the horizontally arranged order of horizontal roller several described；Specifically: structure Build rail profile simplified model and rail tensile stress variation model 301；Draw according to described rail profile simplified model and rail Stretch and the pure resilient bending moment of pure elastic bending, generation bullet occur when STRESS VARIATION model calculates described rail level aligning respectively The elasto bending moment 302 of plastic bending；According to described pure resilient bending moment, described elasto bending torque setting Several horizontal roller drafts are between 0mm-25mm, and drafts is sequentially reduced by the horizontally arranged order of horizontal roller several described 303。

Further, when building rail profile simplified model, the optional section to 60kg/m rail simplifies, as Shown in Fig. 8: b₁=73mm, b₂=150mm, Z₁=95mm, Z₂=81mm, a₁=55.2mm, a₂=61.8mm, t=16.5mm, its In, b₁: rail head width；b₂: flange of rail width；z₁: the distance of rail head surface to neutral axis；z₂: flange of rail surface to neutral axis away from From；a₁: the distance of rail head lower jaw to neutral axis；a₂: the distance of flange of rail upper surface to neutral axis, t is web of the rail thickness；Simultaneously because Rail (high-carbon steel) tensile strength is at more than 880MPa, and during stretching, yield limit is inconspicuous, does not has yield point elongation, and plasticity is occurring There is the phenomenon that elastoplasticity strengthens during deformation, for the ease of analyzing, use bilinearity strong on the tensile stress-strain model of rail Changing model to simplify, as shown in figure 11, in figure, OA and OB line segment analytical expression is: as ε ＜ ε_sTime, σ=E* ε；As ε >=ε_s Time, σ=σ_S+E₁*(ε-ε_s)；Wherein, σ is rail yield strength；σ_SIt it is the rail yield strength limit；ε is strain；ε_sIt is that surrender should Become；E is elastic modelling quantity, E₁For Young's modulus.

Stress and strain model after above-mentioned two aspect model simplifications, during deflection of rail process generation elastic-plastic deformation As shown in Fig. 9 (pure elastic bending), Figure 10 (elasto bending).Below according to flexural deformation degree, rail level is discussed respectively Plastic bending moment when occurring the bending moment of pure elastic bending and elastic-plastic strain to penetrate into different depth during aligning.

1, bending moment during the pure elastic bending of rail generation；When rail head surface bending stress reaches rail yield limit σ_S Time, rail bears the pure resilient bending moment of maximum, and its integral expression is:

$M={\&Integral;}_0^{a_1}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_1}^{z_1}{b}_1\mathrm{\&sigma;}zdz+{\&Integral;}_0^{a_2}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&sigma;}zdz$

In formula, σ=(z/z₁)σ_s, heavy rail cross dimensions data are substituted into, the pure resilient bending moment obtaining maximum is M_{Play max} =0.355 σ_s。

2, bending moment during rail generation elastic-plastic deformation.When bending moment exceedes the elasto bending power that heavy rail is maximum Square M_{Play max}Time, elastic and plastic bending deformation will occur, penetrate into heavy rail section depth according to plastic strain different, can be divided into such as figure Shown in 12-14 four kind situation, wherein, dash area is plastically deforming area, and blank parts is elastic deformation area:

1. plastic strain only penetrates into the partial cut-away of rail head.The now long z in elastic region half₀Meet z₂≤z₀＜ z₁, refer to Figure 12, bending moment integral expression is:

$\begin{array}{c}{M}_1={\&Integral;}_0^{a_1}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_1}^{z_0}{b}_1\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{z_1}{b}_1{\mathrm{\&sigma;}}_{s}zdz+\\ {\&Integral;}_{z_0}^{z_1}{b}_1\mathrm{\&Delta;}\mathrm{\&sigma;}zdz+{\&Integral;}_0^{a_2}t\mathrm{\&sigma;}zdz++{\&Integral;}_{a_2}^{z_0}{b}_2\mathrm{\&sigma;}zdz\end{array}$

In formula, Δ σ=(z-z₀)/z₀σ_sη, σ=(z/z₁)σ_s, wherein, η is hardening coefficient, for Properties of Heavy Rail Steel η=0.08.

2. plastic strain penetrates into the partial cut-away of rail head and the flange of rail.The now long z in elastic region half₀Meet a₂≤z₀＜ z₁, please Refering to Figure 13, bending moment integral expression is:

$\begin{array}{c}{M}_2={\&Integral;}_0^{a_1}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_1}^{z_0}{b}_1\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{z_1}{b}_1{\mathrm{\&sigma;}}_{s}zdz+{\&Integral;}_{z_0}^{z_1}{b}_1\mathrm{\&Delta;}\mathrm{\&sigma;}zdz\\ +{\&Integral;}_0^{a_2}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_2}^{z_0}{b}_2\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{z_2}{b}_2{\mathrm{\&sigma;}}_{s}zdz+{\&Integral;}_{z_0}^{z_2}{b}_2\mathrm{\&Delta;}\mathrm{\&sigma;}zdz\end{array}$

3. plastic strain penetrates into the tunneling boring of rail head and the flange of rail, and also produces with the part web of the rail section of flange of rail junction Plastic strain.The now long z in elastic region half₀Meet a₂≤z₀＜ z₁, referring to Figure 14, bending moment integral expression is:

$\begin{array}{c}{M}_3={\&Integral;}_0^{a_1}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_1}^{z_0}{b}_1\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{z_1}{b}_1{\mathrm{\&sigma;}}_{s}zdz+{\&Integral;}_{z_0}^{z_1}{b}_1\mathrm{\&Delta;}\mathrm{\&sigma;}zdz+{\&Integral;}_0^{z_0}t\mathrm{\&sigma;}zdz\\ +{\&Integral;}_0^{a_2}{\mathrm{t\&sigma;}}_{s}zdz+{\&Integral;}_{a_2}^{z_2}{b}_2{\mathrm{\&sigma;}}_{s}zdz+{\&Integral;}_{z_0}^{a_2}t\mathrm{\&Delta;}\mathrm{\&sigma;}zdz+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&Delta;}\mathrm{\&sigma;}zdz\end{array}$

4. plastic strain penetrates into the tunneling boring of rail head and the flange of rail, and with the part web of the rail section of rail head and flange of rail junction Also plastic strain is created.The now long z in elastic region half₀Meet 0 ＜ z₀＜ a₁, refer to Figure 15, bending moment integral expression For:

$\begin{array}{c}{M}_4=2{\&Integral;}_0^{a_1}t\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{a_1}{\mathrm{t\&sigma;}}_{s}zdz+{\&Integral;}_{a_1}^{z_1}{b}_1{\mathrm{\&sigma;}}_{s}zdz+{\&Integral;}_{z_0}^{a_1}t\mathrm{\&Delta;}\mathrm{\&sigma;}zdz+{\&Integral;}_{a_1}^{z_1}{b}_1\mathrm{\&Delta;}\mathrm{\&sigma;}zdz\\ +{\&Integral;}_{z_0}^{a_2}t\mathrm{\&sigma;}zdz+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&sigma;}zdz+{\&Integral;}_{z_0}^{a_2}t\mathrm{\&Delta;}\mathrm{\&sigma;}zdz+{\&Integral;}_{a_2}^{z_2}{\mathrm{\&Delta;b}}_2\mathrm{\&Delta;}\mathrm{\&sigma;}zdz\end{array}$

In the present embodiment, the rail after pre-bending processes is carried out straightening processing and also includes: by several edger roll displacements Amount is set between 1mm-18mm, and displacement is sequentially reduced by the horizontally arranged order of horizontal roller several described；Specifically: structure Build rail profile simplified model and rail tensile stress variation model 401；Draw according to described rail profile simplified model and rail Stretch and the pure resilient bending moment of pure elastic bending, generation bullet occur when STRESS VARIATION model calculates described rail edger roll aligning respectively The elasto bending moment 402 of plastic bending；According to described pure resilient bending moment, described elasto bending torque setting Several edger roll displacements are between 1mm-18mm, and displacement is sequentially reduced 403 by the horizontally arranged order of edger roll several described.

Further, during vertical aligning, straightening point concentrates on rail head chin part, and heavy rail is risen by the position of roller circle bulge To being drawn effect.Causing the diastrophic exopathogenic factor of heavy rail is moment of flexure, therefore, carries out vertical straightening process from bending moment angle Analyze.Data process for convenience, and the section configuration of 60kg/m heavy rail is done suitable simplification, and the symmetrical axle of heavy rail is neutral Axle, wherein: b₁=73mm, b₂=150mm, z₁=95mm, z₂=81mm, a₁=55.2mm, a₂=61.8mm, t=16.5mm.Order H=a₁+a₂, h₁=z₁-a₁, h₂=z₂-a₂.Identical with rail level aligning analysis process, send out when rail edger roll aligning is discussed respectively The bending moment of raw pure elastic bending and elastic-plastic strain penetrate into plastic bending moment during different depth.

1, bending moment during the pure elastic bending deflection of rail generation；On section bending stress size and this point of certain point from The distance of neutral axis is directly proportional.When heavy rail occurs pure elastic bending deflection, its bending moment integral expression is:

$M=2\&lsqb;{\&Integral;}_0^{\frac{b_2}{2}}{\mathrm{\&sigma;}}_1{h}_{2}zdz+{\&Integral;}_0^{\frac{b_1}{2}}{\mathrm{\&sigma;}}_2{h}_{1}zdz+{\&Integral;}_0^{\frac{t}{2}}{\mathrm{\&sigma;}}_{3}hzdz\&rsqb;$

Section each several part stress distribution is linear elasticity, and its maximum is σ_s, show that each several part STRESS VARIATION isSubstitution above formula obtains:

$\begin{array}{c}M=4{\mathrm{\&sigma;}}_s\&lsqb;{\&Integral;}_0^{\frac{b_2}{0}}\frac{h_2}{b_2}{z}^{2}dz+{\&Integral;}_0^{\frac{b_1}{2}}\frac{h_1}{b_1}{z}^{2}dz+{\&Integral;}_0^{\frac{t}{2}}\frac{h}{t}{z}^{2}dz\&rsqb;\\ =4{\mathrm{\&sigma;}}_s\&lsqb;\frac{h_2}{b_2}{\&Integral;}_0^{\frac{b_2}{2}}{z}^{2}dz+\frac{h_1}{b_1}{\&Integral;}_0^{\frac{b_1}{2}}{z}^{2}dz+\frac{h}{t}{\&Integral;}_0^{\frac{t}{2}}{z}^{2}dz\&rsqb;\\ =\frac{1}{6}\&lsqb;h_2{b}_2^2+h_1{b}_1^2+{\mathrm{ht}}^2\&rsqb;{\mathrm{\&sigma;}}_s\end{array}$

As a example by yield strength is as 609Mpa, each parameter is substituted into above formula, obtain M=68.67kN m.

2, bending moment during rail generation elastic and plastic bending deformation；Plastic bending moment during aligning:

$M=2\&lsqb;{\&Integral;}_0^{\frac{b_2}{2}}{\mathrm{\&sigma;}}_s{h}_{2}zdz+{\&Integral;}_0^{\frac{h}{2}}{\mathrm{\&sigma;}}_s{h}_{1}zdz+{\&Integral;}_0^{\frac{t}{2}}{\mathrm{\&sigma;}}_{s}hzdz\&rsqb;$

Because tunneling boring is in state of plastic deformation, therefore σ₁=σ₂=σ₃=σ_s, substitute into above formula and arrange and can obtain:

$M=\frac{1}{4}(b_2^2{h}_2+b_1^2{h}_1+{\mathrm{ht}}^2)\&CenterDot;{\mathrm{\&sigma;}}_s$

Each parameter is substituted into obtain M=102.91kN m.

Refer to Figure 16-17, bending force when there is pure elastic bending time to sum up to level aligning and edger roll aligning and sending out Bending moment simulation during raw elastic-plastic deformation and calculating, thus set horizontal roller drafts and ensure between 0mm～25mm, pressure Lower amount gradually reduces；Edger roll displacement ensures that, between 1mm～18mm, displacement gradually reduces.

Below, the hundred meters of high speed heavy rail production methods of a kind of microstress provided the present invention by example 1-5 are at actual job During concrete application elaborate, to support the technical problem to be solved further, wherein, rail arrives Cold bed temperature controls between 800 DEG C～900 DEG C, and before rectifying, temperature controls within 50 DEG C, and straightening of kinked rail rank is 60kg/m, steel Planting is U71Mn, and its chemical composition is shown in Table 1, and the traveling distance of each pre-bending dolly of example 1-5 is shown in Table 2.1-2.5, example 1-5 Ping Lifu Closing straightener drafts and displacement is shown in Table 3.1-3.5, at the bottom of the Rail after example 1-5 aligning, residual stress and mechanical property are shown in Table 4:

Table 1: the chemical composition (wt%) of example 1-5 rail

Composition	C	Si	Mn	P	S
						Example 1	0.6880	0.2490	1.1870	0.0100	0.0110
Example 2	0.6930	0.2430	1.1960	0.0180	0.0120
						Example 3	0.6880	0.2420	1.2060	0.0160	0.0120
Example 4	0.6960	0.2460	1.1940	0.0150	0.0110
						Example 5	0.6880	0.2600	1.1810	0.0130	0.0100

Table 2.1: the stroke (stroke unit is mm) of each pre-bending dolly in example 1

Dolly sequence number	1	2	3	4	5	6	7	8	9	10
											Traversing stroke	420	425	435	455	500	520	580	680	790	900
Dolly sequence number	11	12	13	14	15	16	17	18	19	20
											Traversing stroke	950	1050	1260	1380	1470	1620	1760	1870	1920	2150
Dolly sequence number	21	22	23	24	25	26	27	28	29	30
											Traversing stroke	1920	1870	1760	1620	1470	1380	1260	1050	950	900
Dolly sequence number	31	32	33	34	35	36	37	38	39
											Traversing stroke	790	680	580	520	500	455	435	425	420

Table 2.2: the stroke (stroke unit is mm) of each pre-bending dolly in example 2

Dolly sequence number	1	2	3	4	5	6	7	8	9	10
											Traversing stroke	425	430	440	460	505	525	585	685	795	905
Dolly sequence number	11	12	13	14	15	16	17	18	19	20
											Traversing stroke	955	1055	1265	1385	1475	1625	1765	1875	1925	2155
Dolly sequence number	21	22	23	24	25	26	27	28	29	30
											Traversing stroke	1925	1875	1765	1625	1475	1385	1265	1055	955	905
Dolly sequence number	31	32	33	34	35	36	37	38	39
											Traversing stroke	795	685	585	525	505	460	440	430	425

Table 2.3: the stroke (stroke unit is mm) of each pre-bending dolly in example 3

Dolly sequence number	1	2	3	4	5	6	7	8	9	10
											Traversing stroke	405	410	420	440	485	5025	565	665	775	885
Dolly sequence number	11	12	13	14	15	16	17	18	19	20
											Traversing stroke	935	1035	1245	1365	1455	1605	1745	1855	1905	2135
Dolly sequence number	21	22	23	24	25	26	27	28	29	30
											Traversing stroke	1905	1855	1745	1605	1455	1365	1245	1035	935	885
Dolly sequence number	31	32	33	34	35	36	37	38	39
											Traversing stroke	775	665	565	505	485	440	420	410	405

Table 2.4: the stroke (stroke unit is mm) of each pre-bending dolly in example 4

Table 2.5: the stroke (stroke unit is mm) of each pre-bending dolly in example 5

Dolly sequence number	1	2	3	4	5	6	7	8	9	10
											Traversing stroke	505	510	520	540	585	605	665	785	875	985
Dolly sequence number	11	12	13	14	15	16	17	18	19	20
											Traversing stroke	1035	1145	1345	1465	1555	1705	1885	2055	2205	2345
Dolly sequence number	21	22	23	24	25	26	27	28	29	30
											Traversing stroke	2205	2055	1885	1705	1555	1465	1345	1135	1045	985
Dolly sequence number	31	32	33	34	35	36	37	38	39
											Traversing stroke	875	785	665	605	585	540	520	510	505

Horizontal roller drafts and edger roll displacement (unit is mm) in table 3.1 example 1

Table 3.2: horizontal roller drafts and edger roll displacement (unit is mm) in example 2

Table 3.3: horizontal roller drafts and edger roll displacement (unit is mm) in example 3

Table 3.4: horizontal roller drafts and edger roll displacement (unit is mm) in example 4

Table 3.5: horizontal roller drafts and edger roll displacement (unit is mm) in example 5

Table 4: flange of rail residual stress and mechanical property

From above-mentioned table 4 (flange of rail residual stress and mechanical property) result, a kind of microstress hundred meters that the present invention provides High speed heavy rail production method is not increasing in the case of extras do not carry out heat treatment, by optimizing the stroke of pre-bending dolly And horizontal roller and the drafts of edger roll, meet in the case of " speed per hour 350km standard " require at hundred meters of steel rail straightness, remaining should Power still ensures that within 100Mpa, finally makes less residual stress greatly improve the safety coefficient of train operation； Also reduce production cost simultaneously, add the added value of rail, improve the market competitiveness of rail, have simple to operate, The feature that security performance is high and degree of accuracy is high.

It should be noted last that, above detailed description of the invention only in order to technical scheme to be described and unrestricted, Although the present invention being described in detail with reference to example, it will be understood by those within the art that, can be to the present invention Technical scheme modify or equivalent, without deviating from the spirit and scope of technical solution of the present invention, it all should be contained In the middle of scope of the presently claimed invention.

Claims (7)

1. hundred meters of high speed heavy rail production methods of a microstress, it is characterised in that including:

Temperature control step, temperature when rail arrives cold bed controls in preset temperature section T₁In, described T₁More than austenitizing temperature Degree；Described preset temperature section T₁It it is 800 DEG C-900 DEG C；

Pre-bending step, uses the variations in temperature of ANSYS FEM Simulation rail cooling procedure；Set according to sunykatuib analysis result Determine rail pre-bending amount；Formulate pre-bending curve according to described pre-bending amount, and formulate for rail is carried out according to described pre-bending curve The traveling distance of the pre-bending dolly that pre-bending processes；Traveling distance according to being formulated carries out pre-crook by pre-bending dolly to rail Reason；Wherein, described rail is special-shaped section shaped steel, and the flange of rail rate of cooling of described rail is more than the rail head cooling of described rail Speed；

Straightening step, before rectifying, temperature controls in preset temperature section T₂In, and depress by setting horizontal roller in equipment for straightening respectively Amount, horizontal roller put in order, edger roll drafts and edger roll put in order is carried out at aligning the rail after pre-bending processes Reason；Described preset temperature section T₂It it is 0 DEG C-50 DEG C；

Wherein, the residual stress of described rail is within 100Mpa；The rank of described rail is 60kg/m, and steel grade is U71Mn；

Described rail interlude pre-bending amount sets consistent, is gradually increased, institute when described rail front end pre-bending amount is at pre-bending dolly State rail rear end pre-bending amount at pre-bending dolly time be gradually reduced.

Method the most according to claim 1, it is characterised in that described according to sunykatuib analysis result setting rail pre-bending amount； Formulate pre-bending curve according to described pre-bending amount, and formulate the pre-bending for rail being carried out pre-bending process according to described pre-bending curve The traveling distance of dolly includes:

Stroke according to equation below setting pre-bending dolly and rail pre-bending amount:

$\left\{\begin{array}{cc}y=-7.77\&times;{10}^{-5}{x}^3+8.39\&times;{10}^{-4}{x}^2+0.14x-0.30& 0\&le;x\&le;28.8\\ y=2.5& 28.8<x<80\\ y=-3.23\&times;{10}^{-4}{x}^3+0.08x^2-6.75x+191.50& 80\&le;x\&le;103\end{array}\right.$

Wherein, x is rail length, and y is rail pre-bending amount.

Method the most according to claim 2, it is characterised in that described to through pre-bending process after rail carry out at aligning Reason includes:

By several horizontal roller reduction settings in equipment for straightening between 0mm-25mm, drafts presses several described horizontal roller Horizontally arranged order is sequentially reduced.

Method the most according to claim 3, it is characterised in that described by several horizontal roller reduction settings at 0mm- Between 25mm, drafts is sequentially reduced by the horizontally arranged order of horizontal roller several described and specifically includes:

Build rail profile simplified model and rail tensile stress variation model；

When calculating described rail level aligning respectively according to described rail profile simplified model and rail tensile stress variation model There is the pure resilient bending moment of pure elastic bending, the elasto bending moment of elasto bending occurs；

According to several horizontal roller drafts described in described pure resilient bending moment, described elasto bending torque setting at 0mm- Between 25mm, drafts is sequentially reduced by the horizontally arranged order of horizontal roller several described.

Method the most according to claim 4, it is characterised in that described to through pre-bending process after rail carry out at aligning Reason includes:

Being set between 1mm-18mm by several edger roll displacements in equipment for straightening, displacement presses several described edger roll levels Put in order and be sequentially reduced.

Method the most according to claim 5, it is characterised in that described several edger roll displacements in equipment for straightening are set Between 1mm-18mm, displacement is sequentially reduced by the horizontally arranged order of edger roll several described and specifically includes:

Build rail profile simplified model and rail tensile stress variation model；

When calculating described rail edger roll aligning respectively according to described rail profile simplified model and rail tensile stress variation model There is the pure resilient bending moment of pure elastic bending, the elasto bending moment of elasto bending occurs；

According to several edger roll displacements described in described pure resilient bending moment, described elasto bending torque setting at 1mm- Between 18mm, displacement is sequentially reduced by the horizontally arranged order of edger roll several described.

Method the most according to claim 6, it is characterised in that the expression formula of described rail tensile stress variation model is:

As ε ＜ ε_sTime, σ=E* ε；

As ε >=ε_sTime, σ=σ_S+E₁*(ε-ε_s)；

Wherein, σ is rail yield strength；σ_SIt it is the rail yield strength limit；ε is strain；ε_sIt it is yield strain；E is springform Amount, E₁For Young's modulus.