CN103551437A - Microstress hectometer high-speed heavy rail production method - Google Patents

Abstract

The invention provides a microstress hectometer high-speed heavy rail production method, which comprises the following steps of a temperature control step: controlling the temperature of a steel rail reaching a cold bed to be in a preset temperature range T1; a prebending step: carrying out prebending treatment on the steel rail, reaching the cold bed, with the temperature in the preset temperature range T1; a straightening step: controlling the before-straightening temperature in the preset temperature range T2 and carrying out the straightening treatment on the steel rail subjected to the prebending treatment. The production method provided by the invention realizes the effects that under the conditions of not increasing additional equipment and not carrying out heat treatment, the prebending treatment and the straightening treatment are carried out, so the straightness of the hectometer steel rail meets the requirement of High-Speed Railway Steel Rail TB/T3276 standard, the residue stress is enabled to be within 100MPa, the smaller residue stress is finally realized, the safety factor of the train operation is greatly improved, meanwhile, the production cost is also reduced, the addition value of the steel rail is increased, and the market competitiveness of the steel rail is improved.

Description

Hundred meters of high speed heavy rail production methods of a kind of microstress

Technical field

The invention belongs to metalworking technology field, particularly hundred meters of high speed heavy rail production methods of a kind of microstress.

Background technology

As everyone knows, inhomogeneous cooling, the steel tissue of steel its section after hot rolling or welding undergoes phase transition, steel are received the cold working such as aligning, is subject to External Force Acting can cause residual stress; In addition the microstress that changes in a organized way caused residual stress and intergranule also can cause residual stress.In steel, the existence of residual stress has a great impact the serviceability of steel especially fatigue behaviour, if residual stress is crossed conference and directly affected high-speed railway traffic safety in rail.

Summary of the invention

Technical problem to be solved by this invention be to provide a kind of in Rail Production process, can realize reduce rail in hundred meters of high speed heavy rail production methods of microstress of residual stress.

For solving the problems of the technologies described above, the invention provides hundred meters of high speed heavy rail production methods of a kind of microstress, comprising: temperature control step, temperature when rail is arrived to cold bed is controlled at preset temperature section T ₁in; Pre-bending step, the variations in temperature of employing ANSYS FEM Simulation rail cooling procedure; According to sunykatuib analysis result, set rail pre-bending amount; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance of travelling of the pre-bending dolly of pre-bending processing according to described pre-bending curve; According to the formulated distance of travelling, by pre-bending dolly, rail is carried out to pre-bending processing; Aligning step, before rectifying, temperature is controlled at preset temperature section T ₂in, and by setting respectively, horizontal roller drafts, horizontal roller in equipment for straightening put in order, edger roll drafts and edger roll put in order that the rail after pre-bending is processed is carried out to straightening processing.

Further, according to sunykatuib analysis result, setting rail pre-bending amount comprises: described rail interlude pre-bending amount is set consistent, and described rail rear and front end pre-bending amount increases gradually when pre-bending dolly place.

Further, described according to sunykatuib analysis result setting rail pre-bending amount; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance of travelling of the pre-bending dolly of pre-bending processing and comprise according to described pre-bending curve:

According to following equation, set stroke and the rail pre-bending amount of pre-bending dolly:

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

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

Further, describedly rail after pre-bending is processed carried out to straightening processing comprise: by several horizontal roller reduction settings in equipment for straightening between 0mm-25mm, drafts by horizontal roller described in several horizontally order reduce successively.

Further, described by several horizontal roller reduction settings between 0mm-25mm, drafts by horizontal roller described in several horizontally order reduce successively specifically to comprise: build rail profile simplified model and rail tensile stress variation model; According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the pure elastic bending moment that pure elastic bending occurs when described rail level is aligned, the elasto bending moment that elasto bending occurs; According to several horizontal roller drafts described in described pure elastic bending moment, described elasto bending torque setting, between 0mm-25mm, drafts horizontally sequentially reduces successively by horizontal roller described in several.

Further, describedly rail after pre-bending is processed carried out to straightening processing comprise: several edger roll displacements in equipment for straightening are set between 1mm-18mm, displacement by edger roll described in several horizontally order reduce successively.

Further, described several edger roll displacements in equipment for straightening are set between 1mm-18mm, displacement by edger roll described in several horizontally order reduce successively specifically to comprise: build rail profile simplified model and rail tensile stress variation model; According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the elasto bending moment that pure elastic bending occurs when described rail edger roll is aligned, the elasto bending moment that elasto bending occurs; According to several edger roll displacements described in described pure elastic bending moment, described elasto bending torque setting, between 1mm-18mm, displacement horizontally sequentially reduces successively by edger roll described in several.

Further, described preset temperature section T ₁be: 800 ℃-900 ℃; And/or, described preset temperature section T ₂be: 0 ℃-60 ℃.

Further, 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+ E ₁* (ε-ε _s); Wherein, σ is rail yield strength; σ _sit is the rail yield strength limit; ε is strain; ε _sit is yield strain; E is elastic modelling quantity, E ₁for Young's modulus.

Hundred meters of high speed heavy rail production methods of a kind of microstress provided by the invention, by by temperature at preset temperature section T ₁interior rail carries out pre-bending processing; And temperature is controlled to preset temperature section T ₂rail after interior and pre-bending is processed carries out straightening processing; Realized in the situation that not increasing extras and also not heat-treating, by pre-bending, process and straightening processing makes in the situation that hundred meters of steel rail straightness meet < < rail for high-speed railway > > TB/T3276 standard-required, residual stress guarantees in 100MPa.The less residual stress of final realization improves the safety coefficient of train operation greatly; Also reduced production cost, increased the added value of rail, improved the market competitiveness of rail simultaneously.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings 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 process chart 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; And

The rail that Fig. 3 provides for the embodiment of the present invention carries out the part process chart in horizontal straightening processing process; And

The rail that Fig. 4 provides for the embodiment of the present invention carries out the part process chart in edger roll straightening processing process; And

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

The hot analysis mode result of ANSYS and actual measured results contrast schematic diagram that Fig. 6 provides for the embodiment of the present invention; 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 bilinearity strengthening material ess-strain model schematic diagram that Figure 11 provides for the embodiment of the present invention; And

The plastic strain that Figure 12 provides for the embodiment of the present invention is only penetrated into the part sectional schematic diagram of rail head; And

The plastic strain that Figure 13 provides for the embodiment of the present invention is penetrated into the part sectional schematic diagram of rail head and the flange of rail; And

The plastic strain that Figure 14 provides for the embodiment of the present invention is penetrated into the full section of rail head and the flange of rail, and produces the structural representation of plastic strain with the part web of the rail section of flange of rail junction; And

The plastic strain that Figure 15 provides for the embodiment of the present invention is penetrated into the full section of rail head and the flange of rail, and produces the structural representation of plastic strain with the part web of the rail section of rail head and flange of rail junction; 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.

The specific embodiment

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 clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, the every other embodiment that those of ordinary skills obtain, belongs to the scope of protection of the invention.

As everyone knows, hundred meters of rail are after air cooling, and because each position of rail profile Metal Distribution is different, so cooling velocity and shrink also differently, moreover metal also can cause Volume Changes from austenite to perlitic transformation, all can cause that rail is crooked.Because rail's end portion metal is larger than bottom metal proportion, under equal cooling condition, flange of rail cooling velocity is very fast, and rail head cooling velocity is slower, when the flange of rail is cooled to no longer produce contraction distortion, the temperature of rail head is still higher, in cooling procedure, continue to produce contraction distortion, therefore, after rail head is completely cooling, whole heavy rail will be crooked to rail head, and this flexibility is rectifys antecurvature curvature.Crooked rail cannot be processed, and also cannot use, so finished product rail must be delivered goods with straightened condition, reach straightened condition and just must align rail, when rail flexibility is excessive, straightening deformation certainly will be excessive, result can produce larger residual stress, even rectifys disconnected.Based on above-mentioned analysis, in order to reduce the residual stress after aligning, hundred meters of high speed heavy rail production methods of a kind of microstress that the embodiment of the present invention provides, refer to Fig. 1, comprising:

S101: temperature control step, temperature when rail is arrived to cold bed is controlled at preset temperature section T ₁in;

Particularly, because the too low steel rail spring of temperature in actual job process is excessive, be difficult for pre-bending; Excess Temperature, Rail Surface hardness is lower, easy galled spots in pre-bending process; Guarantee that rail arrives cold bed temperature more than austenitizing temperature in order to guarantee rail in abundant pre-bending and not affect its quality in the situation that, the temperature in the time of rail can being arrived to cold bed is controlled at preset temperature section T ₁in; Preferably, preset temperature section T ₁it is 800 ℃-900 ℃.

S102: pre-bending step, the variations in temperature of employing ANSYS FEM Simulation rail cooling procedure; According to sunykatuib analysis result, set rail pre-bending amount; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance of travelling of the pre-bending dolly of pre-bending processing according to described pre-bending curve; According to the formulated distance of travelling, by pre-bending dolly, rail is carried out to pre-bending processing;

Wherein, rail is special-shaped section shaped steel, and the area of dissipation of section each several part differs larger with the ratio of volume, cooling velocity difference is very large, thereby cause the uneven distribution of temperature on heavy rail section, cause that the amount of contraction of heavy rail section each several part is different, produce thermal stress and hot bending square.Also be that above-mentioned analysis theories is under equal cooling condition, flange of rail cooling velocity is very fast, and rail head cooling velocity is slower, when the flange of rail is cooled to no longer produce contraction distortion, the temperature of rail head is still higher, continues to produce contraction distortion in cooling procedure, therefore, after rail head is completely cooling, whole heavy rail will be crooked to rail head, and this flexibility is rectifys antecurvature curvature.In order reducing, to rectify antecurvature curvature, need to before rectifying, to carry out pre-bending, simultaneously for rational prebending process, can operate according to following concrete steps:

Adopt the variations in temperature 201 of ANSYS FEM Simulation rail cooling procedure; According to sunykatuib analysis result, set rail pre-bending amount 202; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance 203 of travelling of the pre-bending dolly of pre-bending processing according to described pre-bending curve; According to the formulated distance of travelling, by pre-bending dolly, rail is carried out to pre-bending and process 204.

In the present embodiment, adopt ANSYS finite element (Fig. 5 is FEM model) to analyze cooling procedure variations in temperature, by ANSYS heat, analyze the analog result to heavy rail cooling temperature field as seen from Figure 6, substantially identical with actual measured results.According to rail cooling curve, due to the friction between rail and cold bed and the restraining function that is subject to head, two sections of rail self of tail, the cooled bending of interlude is less, and rail interlude pre-bending amount can be made as unanimously, and maintenance rail interlude is straight; And adopt curve, the pre-bending amount at pre-bending dolly place to increase gradually during two sections of pre-bending before and after rail, and formulate pre-bending curve as shown in Figure 7, according to pre-bending curve, take rail length as X-axis, pre-bending amount is Y-axis, curve can be divided into three sections.Two sections of curves are end to end carried out respectively to matching, obtain following pre-bending curvilinear equation and finally according to pre-bending curvilinear equation, formulate the stroke of 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: aligning step, before rectifying, temperature is controlled at preset temperature section T ₂in, and by setting respectively, horizontal roller drafts, horizontal roller in equipment for straightening put in order, edger roll drafts and edger roll put in order that the rail after pre-bending is processed is carried out to straightening processing;

Wherein, because rail is high-carbon steel, in order to guarantee its leveling effect, utilize rail under larger elasto bending condition, no matter its original curved degree has much differences, degree of crook difference residual after spring-go can significantly reduce, and even can reach unanimity; Along with reducing of press-bending degree, the residual bending after its spring-go will inevitably unanimously be tending towards null value and reach aligning object, is subject to larger power during just because of steel rail straightening, so that straightening temperature is difficult for is too high, therefore, before rectifying, temperature is controlled at preset temperature section T ₂in; Preferably, preset temperature section T ₂be: 0 ℃-60 ℃.

In the present embodiment, the rail after pre-bending is processed is carried out to straightening processing and comprise: between 0mm-25mm, drafts horizontally sequentially reduces successively by horizontal roller described in several by several horizontal roller reduction settings; Particularly: build rail profile simplified model and rail tensile stress variation model 301; According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the pure elastic bending moment that pure elastic bending occurs when described rail level is aligned, the elasto bending moment 302 that elasto bending occurs; According to several horizontal roller drafts described in described pure elastic bending moment, described elasto bending torque setting, between 0mm-25mm, drafts horizontally sequentially reduces 303 successively by horizontal roller described in several.

Further, while building rail profile simplified model, can select the section of 60kg/m rail to simplify, as shown in Figure 8: b ₁=73mm, b ₂=150mm, Z ₁=95mm, Z ₂=81mm, a ₁=55.2mm, a ₂=61.8mm, t=16.5mm, wherein, b ₁: rail head width; b ₂: flange of rail width; z ₁: rail head surface is to the distance of neutral axis; z ₂: flange of rail surface is to the distance of neutral axis; a ₁: rail head lower jaw is to the distance of neutral axis; a ₂: flange of rail upper surface is to the distance of neutral axis, and t is web of the rail thickness; Simultaneously because rail (high-carbon steel) tensile strength is more than 880MPa, during stretching, yield limit is not obvious, there is no yield point elongation, the phenomenon that exists elastoplasticity to strengthen when there is plastic deformation, for the ease of analyzing, adopt bilinearity strengthening model to simplify on the tensile stress-strain model of rail, as shown in figure 11, in figure, OA and OB line segment analytical expression are: as ε < ε _stime, σ=E* ε; As ε>=ε _stime, σ=σ _s+ E ₁* (ε-ε _s); Wherein, σ is rail yield strength; σ _sit is the rail yield strength limit; ε is strain; ε _sit is yield strain; E is elastic modelling quantity, E ₁for Young's modulus.

After simplifying for above-mentioned two aspect models, stress and strain model during rail BENDING PROCESS generation elastic-plastic deformation is as shown in Fig. 9 (pure elastic bending), Figure 10 (elasto bending).Following according to flexural deformation degree, the plastic bending moment when pure elastic bending occurs rail level when aligning bending moment and elastic-plastic strain being discussed being respectively penetrated into different depth.

Bending moment when 1, pure elastic bending occurs rail; When rail head surface bending stress reaches rail yield limit σ _stime, rail bears maximum pure elastic bending moment, and its integral expression is:

$M={\&Integral;}_0^{a_1}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_1}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&sigma;zdz}+{\&Integral;}_0^{a_2}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&sigma;zdz}$

In formula, σ=(z/z ₁) σ _s, by the substitution of heavy rail cross dimensions data, obtaining maximum pure elastic bending moment is M _{play max}=0.355 σ _s.

2, bending moment during rail generation elastic-plastic deformation.As the elasto bending moment M of bending moment over heavy rail maximum _{play max}time, will there is elastic and plastic bending deformation, according to plastic strain, be penetrated into heavy rail section depth different, can be divided into four kinds of situations as shown in Figure 12-14, wherein, dash area is plastically deforming area, blank parts is elastic deformation area:

1. plastic strain is only penetrated into the part section of rail head.Elastic region half long z now ₀meet z ₂≤ z ₀< z ₁, referring to Figure 12, bending moment integral expression is:

$\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">M</figure-callout>}}_1={\&Integral;}_0^{a_1}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_1}^{z_0}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&sigma;zdz}+{\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&sigma;}}_s\mathrm{zdz}+\\ {\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&Delta;\&sigma;zdz}+{\&Integral;}_0^{a_2}\mathrm{t\&sigma;zdz}++{\&Integral;}_{a_2}^{z_0}{b}_2\mathrm{\&sigma;zdz}\end{array}$

In formula, Δ σ=(z-z ₀)/z ₀σ _sη, σ=(z/z ₁) σ _s, wherein, η is hardening coefficient, for Properties of Heavy Rail Steel η=0.08.

2. plastic strain is penetrated into the part section of rail head and the flange of rail.Elastic region half long z now ₀meet a ₂≤ z ₀< z ₁, referring to Figure 13, bending moment integral expression is:

$\begin{array}{c}{M}_2={\&Integral;}_0^{a_1}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_1}^{z_0}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&sigma;zdz}+{\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&Delta;\&sigma;zdz}\\ +{\&Integral;}_0^{a_2}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_2}^{z_0}{b}_2\mathrm{\&sigma;zdz}+{\&Integral;}_{z_0}^{z_2}{b}_2{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{z_0}^{z_2}{b}_2\mathrm{\&Delta;\&sigma;zdz}\end{array}$

3. plastic strain is penetrated into the full section of rail head and the flange of rail, and has also produced plastic strain with the part web of the rail section of flange of rail junction.Elastic region half long z now ₀meet a ₂≤ z ₀< z ₁, referring to Figure 14, bending moment integral expression is:

$\begin{array}{c}{\mathrm{<figure-callout\; id="3"\; label="M"\; filenames="HDA0000405885150000062.png"\; state="\{\{state\}\}">M</figure-callout>}}_3={\&Integral;}_0^{a_1}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_1}^{z_0}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&sigma;zdz}+{\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{z_0}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&Delta;\&sigma;zdz}+{\&Integral;}_0^{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="HDA0000405885150000051.png"\; state="\{\{state\}\}">z</figure-callout>}}_0}\mathrm{t\&sigma;zdz}\\ +{\&Integral;}_{z_0}^{a_2}t{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{a_2}^{z_2}{b}_2{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{z_0}^{a_2}\mathrm{t\&Delta;\&sigma;zdz}+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&Delta;\&sigma;zdz}\end{array}$

4. plastic strain is penetrated into the full section of rail head and the flange of rail, and has also produced plastic strain with the part web of the rail section of rail head and flange of rail junction.Elastic region half long z now ₀meet 0 < z ₀< a ₁, referring to Figure 15, bending moment integral expression is:

$\begin{array}{c}{\mathrm{<figure-callout\; id="4"\; label="M"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">M</figure-callout>}}_4=2{\&Integral;}_0^{a_1}\mathrm{t\&sigma;zdz}+{\&Integral;}_{z_0}^{a_1}t{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{a_1}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&sigma;}}_s\mathrm{zdz}+{\&Integral;}_{z_0}^{a_1}\mathrm{t\&Delta;\&sigma;zdz}+{\&Integral;}_{a_1}^{z_1}{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1\mathrm{\&Delta;\&sigma;zdz}\\ +{\&Integral;}_{z_0}^{a_2}\mathrm{t\&sigma;zdz}+{\&Integral;}_{a_2}^{z_2}{b}_2\mathrm{\&sigma;zdz}+{\&Integral;}_{z_0}^{a_2}\mathrm{t\&Delta;\&sigma;zdz}+{\&Integral;}_{a_2}^{z_2}\mathrm{\&Delta;}{b}_2\mathrm{\&Delta;\&sigma;zdz}\end{array}$

In the present embodiment, the rail after pre-bending is processed is carried out to straightening processing and also comprise: several edger roll displacements are set between 1mm-18mm, and displacement horizontally sequentially reduces successively by horizontal roller described in several; Particularly: build rail profile simplified model and rail tensile stress variation model 401; According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the elasto bending moment that pure elastic bending occurs when described rail edger roll is aligned, the elasto bending moment 402 that elasto bending occurs; According to several edger roll displacements described in described pure elastic bending moment, described elasto bending torque setting, between 1mm-18mm, displacement horizontally sequentially reduces 403 successively by edger roll described in several.

Further, while vertically aligning, aligning point is concentrated a lower jaw part in-orbit, and the effect of being drawn is played to heavy rail in the position of roller circle bulge.Cause that the diastrophic external cause of heavy rail is moment of flexure, therefore, from bending moment angle, vertical aligning process is analyzed.In order to facilitate data processing, the section configuration of 60kg/m heavy rail is done to suitable simplification, the symmetrical axle of heavy rail is neutral axis, wherein: b ₁=73mm, b ₂=150mm, z ₁=95mm, z ₂=81mm, a ₁=55.2mm, a ₂=61.8mm, t=16.5mm.Make h=a ₁+ a ₂, h ₁=z ₁-a ₁, h ₂=z ₂-a ₂.Identical with rail level aligning analytic process, the plastic bending moment when the bending moment of pure elastic bending and elastic-plastic strain occurring when rail edger roll aligning is discussed being respectively penetrated into different depth.

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

$M=2[{\&Integral;}_0^{\frac{b_2}{2}}{\mathrm{\&sigma;}}_1{h}_2\mathrm{zdz}+{\&Integral;}_0^{\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}}{\mathrm{\&sigma;}}_2{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">h</figure-callout>}}_1\mathrm{zdz}+{\&Integral;}_0^{\frac{t}{2}}{\mathrm{\&sigma;}}_3\mathrm{hzdz}]$

Section each several part stress distribution is linear elasticity, and its maximum is σ _s, show that each several part STRESS VARIATION is ${\mathrm{\&sigma;}}_1=\frac{2z}{b_2}{\mathrm{\&sigma;}}_s,{\mathrm{\&sigma;}}_2=\frac{2\mathrm{<figure-callout\; id="1"\; label="z\; b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">z</figure-callout>}}{b_{}}{\mathrm{\&sigma;}}_s,{\mathrm{\&sigma;}}_3=\frac{2z}{t}{\mathrm{\&sigma;}}_s$ Substitution above formula obtains:

$M=4{\mathrm{\&sigma;}}_s[{\&Integral;}_0^{\frac{b_2}{2}}\frac{h_2}{b_2}{z}^2\mathrm{dz}+{\&Integral;}_0^{\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}}\frac{h_1}{b_1}{z}^2\mathrm{dz}+{\&Integral;}_0^{\frac{t}{2}}\frac{h}{t}{z}^2\mathrm{dz}]$

$\begin{array}{c}=4{\mathrm{\&sigma;}}_s[\frac{h_2}{b_2}{\&Integral;}_0^{\frac{b_2}{2}}{z}^2\mathrm{dz}+\frac{h_1}{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{\&Integral;}_0^{\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}}{z}^2\mathrm{dz}+\frac{h}{t}{\&Integral;}_0^{\frac{t}{2}}{z}^2\mathrm{dz}]\\ =\frac{1}{6}[h_2{b}_2^2+h_1{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1^2+{\mathrm{ht}}^2]{\mathrm{\&sigma;}}_s\end{array}$

Take yield strength as 609Mpa as example each parameter substitution above formula, obtain M=68.67kNm.

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

$M=2[{\&Integral;}_0^{\frac{b_2}{2}}{\mathrm{\&sigma;}}_s{h}_2\mathrm{zdz}+{\&Integral;}_0^{\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}}{\mathrm{\&sigma;}}_s{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">h</figure-callout>}}_1\mathrm{zdz}+{\&Integral;}_0^{\frac{t}{2}}{\mathrm{\&sigma;}}_s\mathrm{hzdz}]$

Because full section is in state of plastic deformation, therefore σ ₁=σ ₂=σ ₃=σ _s, substitution above formula also arranges and can obtain:

$M=\frac{1}{4}(b_2^2{h}_2+{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">b</figure-callout>}}_1^2{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="HDA0000405885150000092.png"\; state="\{\{state\}\}">h</figure-callout>}}_1+h{t}^2)\&CenterDot;{\mathrm{\&sigma;}}_s$

Each parameter substitution is obtained to M=102.91kNm.

Refer to Figure 16-17, the bending moment when bending force while there is pure elastic bending during to sum up to level aligning and edger roll aligning and generation elastic-plastic deformation is simulated and is calculated, thereby set horizontal roller drafts, guarantees that, between 0mm～25mm, drafts gradually reduces; Edger roll displacement guarantees that, between 1mm～18mm, displacement gradually reduces.

Below, by routine 1-5, to hundred meters of high speed heavy rail production methods of a kind of microstress provided by the invention, the concrete application in actual job process elaborates, further to support technical problem to be solved by this invention, wherein, rail arrives cold bed temperature and is controlled between 800 ℃～900 ℃, before rectifying, temperature is controlled in 50 ℃, straightening of kinked rail rank is 60kg/m, steel grade is U71Mn, its chemical composition is in Table 1, the distance of travelling of each pre-bending dolly of example 1-5 is in Table 2.1-2.5, example 1-5 is flat vertical meets straightener drafts and displacement in Table 3.1-3.5, at the bottom of Rail after example 1-5 aligning, residual stress and mechanical property are in Table 4:

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

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 of each pre-bending dolly in example 1 (stroke unit is mm)

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 of each pre-bending dolly in example 2 (stroke unit is mm)

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 of each pre-bending dolly in example 3 (stroke unit is mm)

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 of each pre-bending dolly in example 4 (stroke unit is mm)

Dolly sequence number	1	2	3	4	5	6	7	8	9	10
											Traversing stroke	485	490	500	520	565	585	645	765	855	965
Dolly sequence number	11	12	13	14	15	16	17	18	19	20
											Traversing stroke	1015	1115	1325	1445	1535	1685	1825	1935	1985	2215
Dolly sequence number	2l	22	23	24	25	26	27	28	29	30
											Traversing stroke	1985	1935	1825	1685	1535	1445	1325	1115	1015	965
Dolly sequence number	3l	32	33	34	35	36	37	38	39	?
											Traversing stroke	855	765	645	585	565	520	500	490	485	?

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

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 in table 3.1 example 1 (unit is mm)

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

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

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

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

Table 4: flange of rail residual stress and mechanical property

From above-mentioned table 4(flange of rail residual stress and mechanical property) result, hundred meters of high speed heavy rail production methods of a kind of microstress provided by the invention are not in the situation that increasing extras and also not heat-treating, by optimizing the stroke of pre-bending dolly and the drafts of horizontal roller and edger roll, in the situation that hundred meters of steel rail straightness meet " speed per hour 350km standard " requirement, residual stress still can guarantee, in 100Mpa, finally to make less residual stress improve greatly the safety coefficient of train operation; Also reduced production cost, increased the added value of rail, improved the market competitiveness of rail, there is feature simple to operate, that security performance is high and accuracy is high simultaneously.

It should be noted last that, the above specific embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to example, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not departing from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.

Claims (9)

1. hundred meters of high speed heavy rail production methods of microstress, is characterized in that, comprising:

Temperature control step, temperature when rail is arrived to cold bed is controlled at preset temperature section T ₁in;

Pre-bending step, the variations in temperature of employing ANSYS FEM Simulation rail cooling procedure; According to sunykatuib analysis result, set rail pre-bending amount; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance of travelling of the pre-bending dolly of pre-bending processing according to described pre-bending curve; According to the formulated distance of travelling, by pre-bending dolly, rail is carried out to pre-bending processing;

Aligning step, before rectifying, temperature is controlled at preset temperature section T ₂in, and by setting respectively, horizontal roller drafts, horizontal roller in equipment for straightening put in order, edger roll drafts and edger roll put in order that the rail after pre-bending is processed is carried out to straightening processing.

2. method according to claim 1, is characterized in that, sets rail pre-bending amount comprise according to sunykatuib analysis result:

Described rail interlude pre-bending amount is set consistent, and described rail rear and front end pre-bending amount increases gradually when pre-bending dolly place.

3. method according to claim 2, is characterized in that, described according to sunykatuib analysis result setting rail pre-bending amount; According to described pre-bending amount, formulate pre-bending curve, and formulate for rail being carried out to the distance of travelling of the pre-bending dolly of pre-bending processing and comprise according to described pre-bending curve:

According to following equation, set stroke and the rail pre-bending amount of pre-bending dolly:

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

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

4. method according to claim 3, is characterized in that, describedly rail after pre-bending is processed is carried out to straightening processing comprises:

By several horizontal roller reduction settings in equipment for straightening, between 0mm-25mm, drafts horizontally sequentially reduces successively by horizontal roller described in several.

5. method according to claim 4, is characterized in that, described by several horizontal roller reduction settings between 0mm-25mm, drafts by horizontal roller described in several horizontally order reduce successively specifically to comprise:

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

According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the pure elastic bending moment that pure elastic bending occurs when described rail level is aligned, the elasto bending moment that elasto bending occurs;

According to several horizontal roller drafts described in described pure elastic bending moment, described elasto bending torque setting, between 0mm-25mm, drafts horizontally sequentially reduces successively by horizontal roller described in several.

6. method according to claim 5, is characterized in that, describedly rail after pre-bending is processed is carried out to straightening processing comprises:

Several edger roll displacements in equipment for straightening are set between 1mm-18mm, and displacement horizontally sequentially reduces successively by edger roll described in several.

7. method according to claim 6, is characterized in that, described several edger roll displacements in equipment for straightening are set between 1mm-18mm, displacement by edger roll described in several horizontally order reduce successively specifically to comprise:

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

According to described rail profile simplified model and rail tensile stress variation model, calculate respectively the elasto bending moment that pure elastic bending occurs when described rail edger roll is aligned, the elasto bending moment that elasto bending occurs;

According to several edger roll displacements described in described pure elastic bending moment, described elasto bending torque setting, between 1mm-18mm, displacement horizontally sequentially reduces successively by edger roll described in several.

8. method according to claim 7, is characterized in that:

Described preset temperature section T ₁be: 800 ℃-900 ℃;

And/or,

Described preset temperature section T ₂be: 0 ℃-60 ℃.

9. method according to claim 8, is characterized 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+ E ₁* (ε-ε _s);

Wherein, σ is rail yield strength; σ _sit is the rail yield strength limit; ε is strain; ε _sit is yield strain; E is elastic modelling quantity, E ₁for Young's modulus.

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