CN101967541B - Heating method for controlling decarburization in heavy rail billet furnace - Google Patents
Heating method for controlling decarburization in heavy rail billet furnace Download PDFInfo
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- CN101967541B CN101967541B CN 201010524656 CN201010524656A CN101967541B CN 101967541 B CN101967541 B CN 101967541B CN 201010524656 CN201010524656 CN 201010524656 CN 201010524656 A CN201010524656 A CN 201010524656A CN 101967541 B CN101967541 B CN 101967541B
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Abstract
The invention provides a heating method for controlling decarburization in a heavy rail billet furnace in a heat accumulation heating mode. The heating process comprises a pre-heating section, a heating section and a soaking section. A furnace pressure measurement point is positioned at the pre-heating section; the full furnace is controlled at positive pressure; when the billet temperature is controlled to be less than 1,000 DEG C, the atmosphere in the furnace is oxidizing atmosphere, and the air consumption coefficient is between 1.05 and 1.25; and when the billet temperature is controlled to be more than or equal to 1,000 DEG C, the atmosphere in the furnace is weak reducing atmosphere, the air consumption coefficient is between 0.9 and 1.0. Aiming at the operation and decarburization characteristics of the heat accumulation heating furnace different from the traditional heating furnace, the segment control method is adopted on the control aspects of atmosphere in the furnace and temperature, and a limit low-oxygen concentration burning process is realized. The method has the advantages of low heated billet surface decarburization, low oxidized burning loss, high furnace energy utilization, low pollutant discharge, low production cost and the like, is simple, convenient and feasible, and can achieve good effect of saving materials and energy at the same time of improving the heating quality of products.
Description
Technical field
The invention belongs to the technical field of material heat treatment, specifically refer to a kind of heating means of controlling decarburization in heavy rail billet furnace.
Background technology
Because the carbon content of Properties of Heavy Rail Steel By is higher, so be easy to occur oxidation and decarburization in the heat-processed before rolling.And the decarburization meeting on rail top layer causes the lower hardness of Rail Surface, and simultaneously wear-resisting, anti-stripping performance descends, and fatigue strength also can reduce.So how effectively to control the decarburized layer deepness of heavy rail product and be technological difficulties in the Rail Production always.
Steel billet surface decarburization layer in heating process in the stove forms influence factor and mainly contains aspect three of atmosphere, heat-up time and the Heating temperatures etc. in the process furnace.Heat-up time is longer, and temperature is higher, and the Decarburized layer of rail is darker.And be the degree of depth that reducing atmosphere is conducive to reduce the rail Decarburized layer in the soaking pit.
Application number is to disclose a kind of heating means that prevent high-carbon steel billet or steel ingot decarburization in the patent of ZL03117411.6.The method is in high carbon steel heating period or in warming up period, heating period, the whole heat-processed of soak, adopts strong oxidizing property atmosphere heating steel billet or steel ingot.
Application number is to disclose a kind of heating means that prevent high carbon belt steel bloom decarburization in the patent of ZL200710115641.1.The method is to adopt pressure-fired, weak oxide atmosphere heating zone steel billet in heat-processed.
In addition, also having class methods is to prevent the steel billet decarburization at high carbon steel surface applying protecting coat.For example, according to " high carbon steel anti-decarburization supercoat research " in " steel rolling " fourth phase in 1996 literary composition, can make decarburization qualification rate raising 20% at the surperficial stopping off of bearing steel.
Above three kinds of methods that prevent decarburization respectively have relative merits and range of application.Be weak oxide atmosphere in the soaking pit and prevent that the method method of decarburization is simple to operate, but because combustion air is not enough, fuel can not perfect combustion, has energy dissipation, and it is high to enter in the waste gas of atmosphere CO content, contaminate environment.The heating means of strong oxidizing atmosphere have caused again the increase of steel billet or steel ingot oxidization burning loss in the employing stove, have reduced the product lumber recovery.At the surperficial applying protecting coat of steel billet, effective, but increased production cost and workman's labour intensity, also be not suitable for the scale operation of Iron And Steel Industry.
In addition, these the three kinds methods that prevent decarburization are mainly for the exploitation of traditional heating stove heating mode, and Application effect is not fairly obvious for recently emerging Energy-efficient Regenerative Type During process furnace.Recuperative heater has different temperature field in furnace, concentration field and pressure field characteristic with respect to the traditional heating stove and accessory, and the surface decarburization forming process when directly having influence on steel billet and heating in stove.For the different operation characteristics of recuperative heater, need the novel method of the corresponding control of exploitation decarburization in heavy rail billet furnace.
Summary of the invention
The objective of the invention is according to above-mentioned deficiency, the effectively heating means of control decarburization in heavy rail billet furnace are provided under a kind of heat accumulating type heating mode that is suitable for scale operation, it is more shallow that this heating means not only can be controlled heavy rail product surface decarburized layer deepness, and can enhance product performance and lumber recovery.
The present invention is achieved through the following technical solutions: the heating means of control decarburization in heavy rail billet furnace under a kind of heat accumulating type heating mode, and described heat-processed comprises preheating section, heating zone and soaking zone, it is characterized in that: the furnace pressure measuring point is positioned at preheating section; Control full stove and keep malleation; Be oxidizing atmosphere in the stove during control steel billet temperature＜1000 ℃, the air consumption coefficient is between 1.05-1.25; Be weak reducing atmosphere in the stove during control steel billet temperature 〉=1000 ℃, the air consumption coefficient is between 0.9-1.0.
Control full stove air consumption coefficient between 1.0-1.05.
Temperature is between 900-1300 ℃ in the control stove.
Described heating zone is divided into upper segment and lower section, and wherein the Heating temperature of lower section is than the high 10-50 of upper segment ℃.
Rate of heating in the described heating zone is 7-10 ℃/min.
Described heating zone control heats up with top speed.
Use the equipment of the heating means of above-mentioned control decarburization in heavy rail billet furnace to be the heat accumulating type walking beam heating furnace.
The commutation cycle of described recuperative heater with point of fixity furnace temperature value temporal evolution for hour determining.
The present invention is directed to the operation that is different from the traditional heating stove and decarburization characteristics that recuperative heater has, aspect the control of furnace atmosphere and temperature, taked the method for segmentation control, realized a kind of limit low oxygen concentration combustion processes.The present invention passes through to adjust the position of furnace pressure measuring point from the soaking zone to the preheating section, control the comprehensive atmosphere of full stove in a kind of Limiting Level near neutrality, guaranteed that heating billet surface decarburized layer deepness is controlled in the most shallow scope, guaranteed again simultaneously the perfect combustion of fuel, improved energy utilization rate and reduced pollutant emission.The present invention is at the strategy of taking rapid heating aspect the temperature control, shorten heat-up time, rationally determine simultaneously the recuperative heater commutation cycle, to guarantee the Control for Kiln Temperature precision, not only can effectively reduce the formation of billet surface decarburization, simultaneously also the oxidization burning loss of steel billet can be controlled at minimum degree, improve the lumber recovery of product.The present invention with compare in methods such as billet surface applying protecting coats, reduced production cost and labour intensity.The present invention and reducing atmosphere prevent that the method for decarburization from comparing, and having improved can energy utilization rate, reduces pollutant emission.The present invention compares with the heating means of strong oxidizing atmosphere, has reduced the oxidization burning loss of steel billet, improves the product lumber recovery.The present invention has the plurality of advantages such as the decarburization of heating billet surface is few, oxidization burning loss is low, the stove energy utilization is high, pollutant emission is low, production cost is low, simple and easy to do, can reach the good result of saving metal material and energy when improving control of industrial furnace home.
Embodiment
By the following specific examples further illustrate the invention:
Embodiment 1
When producing 50Kg/m level U71Mn high speed heavy rail (carbon content 0.68-0.74%), the rolling line method flow is: the continuously cast bloom raw material weighs → the heat accumulating type walking beam reheating furnace in heating → high-pressure water descaling → BD1 cogging → BD2 abnormity rolling → UEU type tandem universal rolling → hot print → hot saw crop → walking beam cooler cools off.Bloom (the cross dimensions 380 * 280mm) that heating is come from continuous caster in the heat accumulating type walking beam heating furnace.At first heat the steel billet horizontal positioned and pack in the stove, wide (380mm place, limit face) level, leptoprosopy (280mm place, limit face) is vertical, arranges with minimum spacing between the steel billet in the stove.Because distribution and the non-uniform Distribution of steel billet surface decarburization layer in heating process in the stove, will be a little more than the trend of vertical surface but show horizontal plane, produce face with leptoprosopy (side) as rail head when rolling, also because leptoprosopy has larger deflection than wide mask, the practical decarburized depth of rolling rear product can be optimized to a best level under the double factor effect simultaneously.With blast furnace gas double heat storage type mode open firing, heat-processed comprises preheating section, a heating zone, two heating zones and soaking zone to steel billet in process furnace subsequently, and wherein preheating section is not established the burner heat supply point.
Full stove keeps malleation in the heat-processed of steel billet, and the furnace pressure measuring point is arranged in preheating section furnace roof middle part, and the controling of the pressure of the oven value remains between the 10-30Pa.Furnace atmosphere is regulated to control the total air consumption coefficient of full stove, controlling valu remains between the 1.0-1.05, wherein low-temperature zone (steel billet temperature＜1000 ℃ time) is under oxidizing atmosphere, the air consumption coefficient is controlled at about 1.05, under weak reducing atmosphere, the air consumption coefficient is controlled at about 0.9 high temperature section (steel billet temperature 〉=1000 ℃ time).Comprehensive atmosphere actual measurement oxygen level is between 0-2% in the stove, and this atmosphere state has guaranteed that namely heating billet surface decarburized layer deepness is controlled in the most shallow scope, has guaranteed again the perfect combustion of fuel simultaneously, has improved energy utilization rate and has reduced pollutant emission.The recuperative heater commutation cycle is determined for hour state with any point furnace temperature cyclic swing value in the stove in the heat-processed, and when the commutation cycle was 48s in the present embodiment, the furnace temperature fluctuation value had guaranteed the Control for Kiln Temperature precision by having dropped to 20 ℃ of minimum value more than 100 ℃.Furnace temperature of heating furnace span of control one heating zone is 1000-1100 ℃, two heating zones are 1200-1250 ℃, soaking zone is 1220-1270 ℃, and the control of lower section temperature exceeds 10-50 ℃ of upper segment temperature, eliminate furnace bottom water beam to the impact of steel billet underlaying surface temperature, improve the billet heating temperature homogeneity, shorten heat-up time.The heating zone rate of heating reaches 7 ℃/min, steel billet time inside furnace 200min, owing to taking the strategy of rapid heating, further shortened heat-up time, not only can effectively reduce the formation of billet surface decarburization, simultaneously also the oxidization burning loss of steel billet can be controlled at minimum degree, improve the lumber recovery of product.
Embodiment 2
Full stove keeps malleation in the heat-processed of steel billet, and the furnace pressure measuring point is arranged in preheating section furnace roof middle part, and the controling of the pressure of the oven value remains between the 10-30Pa.Furnace atmosphere is regulated to control the total air consumption coefficient of full stove, controlling valu remains between the 1.0-1.05, wherein low-temperature zone (steel billet temperature＜1000 ℃ time) is under oxidizing atmosphere, the air consumption coefficient is controlled at about 1.25, under weak reducing atmosphere, the air consumption coefficient is controlled at about 1.0 high temperature section (steel billet temperature 〉=1000 ℃ time).Comprehensive atmosphere actual measurement oxygen level is between 0-2% in the stove, and this atmosphere state has guaranteed that namely heating billet surface decarburized layer deepness is controlled in the most shallow scope, has guaranteed again the perfect combustion of fuel simultaneously, has improved energy utilization rate and has reduced pollutant emission.The recuperative heater commutation cycle is determined for hour state with any point furnace temperature cyclic swing value in the stove in the heat-processed, and when the commutation cycle was 48s in the present embodiment, the furnace temperature fluctuation value had guaranteed the Control for Kiln Temperature precision by having dropped to 20 ℃ of minimum value more than 100 ℃.Furnace temperature of heating furnace span of control one heating zone is 900-1000 ℃, two heating zones are 1000-1150 ℃, soaking zone is 1200-1270 ℃, and the control of lower section temperature exceeds 10-50 ℃ of upper segment temperature, eliminate furnace bottom water beam to the impact of steel billet underlaying surface temperature, improve the billet heating temperature homogeneity, shorten heat-up time.The heating zone rate of heating reaches 10 ℃/min, steel billet time inside furnace 160min, owing to taking the strategy of rapid heating, further shortened heat-up time, not only can effectively reduce the formation of billet surface decarburization, simultaneously also the oxidization burning loss of steel billet can be controlled at minimum degree, improve the lumber recovery of product.
Embodiment 3
Full stove keeps malleation in the heat-processed of steel billet, and the furnace pressure measuring point is arranged in preheating section furnace roof middle part, and the controling of the pressure of the oven value remains between the 10-30Pa.Furnace atmosphere is regulated to control the total air consumption coefficient of full stove, controlling valu remains between the 1.0-1.05, wherein low-temperature zone (steel billet temperature＜1000 ℃ time) is under oxidizing atmosphere, the air consumption coefficient is controlled at about 1.1, under weak reducing atmosphere, the air consumption coefficient is controlled at about 0.95 high temperature section (steel billet temperature 〉=1000 ℃ time).Comprehensive atmosphere actual measurement oxygen level is between 0-2% in the stove, and this atmosphere state has guaranteed that namely heating billet surface decarburized layer deepness is controlled in the most shallow scope, has guaranteed again the perfect combustion of fuel simultaneously, has improved energy utilization rate and has reduced pollutant emission.The recuperative heater commutation cycle is determined for hour state with any point furnace temperature cyclic swing value in the stove in the heat-processed, and when the commutation cycle was 48s in the present embodiment, the furnace temperature fluctuation value had guaranteed the Control for Kiln Temperature precision by having dropped to 20 ℃ of minimum value more than 100 ℃.Furnace temperature of heating furnace span of control one heating zone is 1000-1100 ℃, two heating zones are 1240-1300 ℃, soaking zone is 1220-1270 ℃, and the control of lower section temperature exceeds 10-50 ℃ of upper segment temperature, eliminate furnace bottom water beam to the impact of steel billet underlaying surface temperature, improve the billet heating temperature homogeneity, shorten heat-up time.The heating zone rate of heating reaches 9 ℃/min, steel billet time inside furnace 180min, owing to taking the strategy of rapid heating, further shortened heat-up time, not only can effectively reduce the formation of billet surface decarburization, simultaneously also the oxidization burning loss of steel billet can be controlled at minimum degree, improve the lumber recovery of product.
After the billet rolling that adopts heating means of the present invention to produce became the heavy rail product of 50Kg/m level, on average about 0.26mm, minimum value reached below the 0.18mm, greatly reduces than prior art, has good effect through master meter emaciated face carbon-coating thickness.
Claims (4)
1. heating means of controlling decarburization in heavy rail billet furnace, it is to carry out under the heat accumulating type heating mode, heat-processed comprises preheating section, heating zone and soaking zone, it is characterized in that: the furnace pressure measuring point is positioned at preheating section; Control full stove and keep malleation; Be oxidizing atmosphere in the stove during control steel billet temperature＜1000 ℃, the air consumption coefficient is between 1.05-1.25; Be weak reducing atmosphere in the stove during control steel billet temperature 〉=1000 ℃, the air consumption coefficient is between 0.9-1.0; Control full stove air consumption coefficient between 1.0-1.05; Temperature is between 900-1300 ℃ in the control stove; Described heating zone is divided into upper segment and lower section, and wherein the Heating temperature of lower section is than the high 10-50 of upper segment ℃; Equipment is the heat accumulating type walking beam heating furnace.
2. the heating means of control decarburization in heavy rail billet furnace according to claim 1, it is characterized in that: the rate of heating in the described heating zone is 7-10 ℃/min.
3. the heating means of control decarburization in heavy rail billet furnace according to claim 2 is characterized in that: described heating zone control heats up with top speed.
4. the equipment of the heating means of control decarburization in heavy rail billet furnace according to claim 1 is characterized in that: the commutation cycle of described process furnace with point of fixity furnace temperature value temporal evolution for hour determining.
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Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102268518A (en) * | 2011-07-25 | 2011-12-07 | 武汉钢铁(集团)公司 | Test method for heating and decarburization of continuous casting blank of high carbon steel |
| CN102240671A (en) * | 2011-07-25 | 2011-11-16 | 武汉钢铁(集团)公司 | Rolling method capable of controlling decarburization of steel rail head |
| CN103060539B (en) * | 2012-12-31 | 2017-02-22 | 江苏兴达钢帘线股份有限公司 | Method for controlling decarburization of fine heat-treated steel wire |
| CN103667647B (en) * | 2013-12-05 | 2016-01-20 | 武汉钢铁(集团)公司 | The optimizing and controlling method of MnS inclusion in Properties of Heavy Rail Steel By |
| CN104726632A (en) * | 2015-03-19 | 2015-06-24 | 河北钢铁股份有限公司邯郸分公司 | Method capable of enhancing dephosphorization rate of heavy rail steel converter smelting |
| CN105483602B (en) * | 2015-12-16 | 2018-03-09 | 武汉科技大学 | A kind of heating means for reducing heavy rail decarburized layer |
| CN109023044B (en) * | 2018-08-01 | 2021-03-09 | 邯郸钢铁集团有限责任公司 | Method for controlling depth of decarburized layer of heavy rail steel |
| CN109266830A (en) * | 2018-09-29 | 2019-01-25 | 邯郸钢铁集团有限责任公司 | A kind of heating production method controlling high-carbon rail decarburized layer deepness |
| CN111809027A (en) * | 2020-07-20 | 2020-10-23 | 武汉钢铁有限公司 | Heating method of copper-containing high-carbon corrosion-resistant steel rail |
| CN112575155B (en) * | 2020-12-03 | 2022-07-19 | 攀钢集团攀枝花钢铁研究院有限公司 | Process for controlling decarburization layer of steel billet |
| CN113215365B (en) * | 2021-04-25 | 2022-10-14 | 南京钢铁股份有限公司 | Decarburization and consumption reduction method for wire heating furnace |
| CN114789194B (en) * | 2022-04-06 | 2023-06-13 | 邯郸钢铁集团有限责任公司 | Two-fire-formed bearing steel wire rod heating and rolling method |
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