CN115091147A - Cold-drawing forming method of precision welded pipe - Google Patents
Cold-drawing forming method of precision welded pipe Download PDFInfo
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- CN115091147A CN115091147A CN202211022529.4A CN202211022529A CN115091147A CN 115091147 A CN115091147 A CN 115091147A CN 202211022529 A CN202211022529 A CN 202211022529A CN 115091147 A CN115091147 A CN 115091147A
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Abstract
The invention discloses a cold-drawing forming method of a precision welded pipe, which comprises the following steps: s1, forming and winding a steel strip; s2, welding to form a welded pipe; s3, removing inner and outer burrs of the welding seam; s4, sizing the blank pipe; s5, straightening; s6, degreasing; s7, cleaning; s8, rust prevention; s9, carrying out heat treatment on the blank tube, wherein the specific method is as follows: introducing natural gas into an inlet of the combustion furnace and an outlet of the heat-preservation cooling section and igniting the natural gas to form a fire curtain; the special gas generated by incomplete combustion of natural gas forms reducing gas after freezing and dehumidification, and the reducing gas is blown in from the upstream position of the heat-preservation cooling section; s10, forming a tip; s11, soaking in reactive drawing oil: s12, draining; s13, cold drawing; and S14, straightening, detecting a flaw, cutting to length, inspecting, packaging and warehousing. The cold-drawing forming method can better control the cold-drawing quality of the welded pipe, so that the welded pipe subjected to cold-drawing has low surface roughness and the integral welded pipe has better stability of surface quality.
Description
Technical Field
The invention relates to a cold-drawing forming method of a precision welded pipe, which is used for cold-drawing forming of the welded pipe.
Background
At present, the commonly used steel pipes mainly comprise welded pipes and seamless steel pipes, the welded pipes are higher in production efficiency and lower in cost compared with the seamless steel pipes, so that the welded pipes are widely applied, but the seamless steel pipes are formed by directly drawing a metal bar without a welding step, so that the surfaces of the seamless steel pipes are smoother, the roughness is low, and the seamless steel pipes are frequently used in the fields with high precision requirements. The method is mainly limited by a manufacturing process of the welded pipe, and the current manufacturing process of the welded pipe mainly comprises the following steps: carbon steel band-reelpipe forming-high frequency weld seam welding-removing internal and external burrs of weld seam → sizing and shaping of blank pipe → eddy current inspection of weld seam → straightening of blank pipe length → cutting to length of blank pipe → inspection → degreasing of blank pipe 1 → rinsing 2 → drying → heat treatment → degreasing of blank pipe 2 → rinsing 2 → acid cleaning → rinsing 3 → neutralization → rinsing 4 → surface conditioning → phosphating → rinsing 5 → draining of blank pipe → drawing tip of blank pipe → soaking oil → drawing of blank pipe → straightening of welded pipe → eddy current inspection → cutting to length of fixed length → inspection → packaging → warehousing. The steps are relatively complicated, wherein the welded pipe subjected to heat treatment needs to be subjected to acid cleaning, neutralization, surface conditioning and phosphorization, so that the process is complex, the water consumption is high, and the generated wastewater is difficult to treat. In view of the above, patent document No. 201410126773.4 discloses a method for manufacturing a precision welded pipe, which can manufacture a precision welded pipe having a roughness controlled to 0.2 μm or less, but has the following problems: 1. the method mentions that: the method comprises the steps of removing water components in DX gas generated by incomplete combustion of natural gas and air after the DX gas is cooled to forty-zero degrees to thirty-zero degrees, heating, introducing the DX gas into a bright annealing furnace for protection and reduction, and meanwhile, recording the method, wherein the DX gas is cooled by adopting coil water, the water cooling water pressure is 0.4-0.6MPa, obviously, the DX gas cannot be cooled to forty-zero degrees to thirty-zero degrees by using the coil water, and the mode is difficult to realize cooling of forty-zero degrees; 2. in the method, DX gas of forty-zero degrees to thirty-zero degrees enters an annealing furnace to contact a welded steel pipe, although the fact that the whole annealing section and a cooling section are required to be carried out in an oxygen-free environment is recorded, no measures and means are provided to ensure that the annealing section and the cooling section can be in the oxygen-free environment all the time, particularly, an inlet and an outlet of the annealing furnace are required to be opened to facilitate the passing of the steel pipe, therefore, some oxygen can enter the annealing furnace all the time, air cooling is also used in the cooling section of the annealing furnace, so that gas is required to be continuously introduced, the gas cannot be used, only nitrogen or other gases can be used, the using amount of the nitrogen is increased, the use cost is increased rapidly, and meanwhile, because other gases are also introduced in the heat-insulation cooling section, the content of reducing gas in the furnace is difficult to ensure, the DX gas can not be ensured to well reduce the oxide layer on the surface of the steel pipe, and meanwhile, the welded pipe is influenced by the flow velocity, flow and content of the reducing gas, the running speed of the welded pipe and the like in an annealing furnace, so that the reduction quality of the oxide layer is more difficult to control; 3. in the method, the welding tube is soaked in the drawing oil, the drawing oil can react in the soaking process of the welding tube, so the cost of the drawing oil is fluctuated, and the drawing oil is relatively viscous, and when the drawing oil is soaked in an oil groove, the situations of precipitation and the like can occur, so that the components of the upper layer and the lower layer of the drawing oil are uneven; in addition, the acid value and the water content of the drawing oil have great influence on the iron-based phosphating film, the method cannot realize the stability of controlling the components of the drawing oil in the long-term process, and the stability of the components of the drawing oil is the key for ensuring the stability of the overall quality of the drawing pipes in the same batch.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the cold-drawing forming method of the precise welded pipe can better control the cold-drawing quality of the welded pipe, so that the welded pipe after cold-drawing has low surface roughness and better stability of the integral surface quality of the welded pipe.
In order to solve the technical problems, the technical scheme of the invention is as follows: a cold-drawing forming method of a precision welded pipe comprises the following steps:
s1, cold rolling and cutting the formed steel plate to form a steel strip coil;
s2, forming the steel strip reel pipe and welding the steel strip reel pipe into a welded pipe through high-frequency welding;
s3, removing inner and outer burrs of the welding seam to form a blank pipe;
the process for removing the outer burrs of the welding seam comprises the following steps: removing burrs of the outer welding seam of the welded pipe by using a hard alloy outer arc blade, wherein the removed outer surface of the welding seam is smoothly and smoothly transited with other outer surfaces of the blank pipe, and the height difference is-0.03 to-0.02 mm;
the removing process of burrs in the welding seam comprises the following steps: removing welding seam burrs in the welded pipe by using an inner circular arc scraper for titanium plating of hard alloy, wherein the removed welding seam surface is in smooth transition with other inner surfaces of the blank pipe, and the height difference is-0.05 to-0.03 mm;
s4, sizing the blank pipe, wherein the tolerance of the outer diameter of the sized blank pipe is-0.20-0.2 mm;
s5, straightening the blank pipe, wherein the straightness of the blank pipe is 0.8-1.3 mm/m after the blank pipe is straightened by a straightening machine;
s6, soaking the blank tube in degreasing liquid for degreasing, wherein the degreasing temperature is controlled to be 75-85 ℃, and the free alkalinity of the degreasing liquid is 20-30;
s7, washing the degreased blank pipe with clear water for two times;
s8, soaking the cleaned blank pipe into an antirust agent for antirust treatment, wherein the free alkalinity of the antirust agent is 2-4;
s9, carrying out heat treatment on the rustproof blank pipe in an atmosphere roller hearth furnace, wherein the specific method is as follows: the furnace body is divided into a preheating section, a heating section and a heat-preservation cooling section according to the process flow direction, natural gas and air are incompletely combusted in a combustion furnace, and the combustion furnace is used as the preheating section and is connected with an inlet of the heating section; the flow of the natural gas of the combustion furnace is 15-30 m 3 H: the flow rate of the air is 150-220 m 3 The volume percentage concentration of carbon monoxide gas in the furnace is 7.0-8.5%, the running speed of the blank tube in the furnace is 0.8-1.2 m/min, and the heating temperature is 550-650 ℃; introducing natural gas into an inlet of the combustion furnace and an outlet of the heat-preservation cooling section and igniting the natural gas to form a fire curtain;
the other path of natural gas and air are completely combusted to heat the radiant tube of the heating section to carry out heat treatment on the blank tube, the heating temperature is 720-740 ℃, special gas generated by incomplete combustion of the natural gas is frozen and dehumidified to form reducing gas, the reducing gas is blown in from the upstream position of the heat-preservation cooling section, and the temperature of the cooled reducing gas entering the furnace is 4-6 ℃; the heat-preservation cooling section of the furnace body adopts a water-cooling coil pipe to exchange heat with the inside of the furnace to form a heat-preservation cooling section, and the heat-preservation cooling section adopts a stepped heat-preservation cooling section;
s10, closing one end of the blank tube to form a tip convenient for cold drawing;
s11, soaking the blank tube into reactive drawing oil to generate an iron-based phosphating film, wherein the specific method comprises the following steps:
a. adding drawing oil with the water content of 0.8-1.5% by mass and the acid value of 70-90% into an oil groove, and heating the drawing oil in the oil groove by using a temperature control device to control the temperature to be 60-70 ℃;
b. obliquely soaking the blank pipe into drawing oil in an oil groove at an inclination angle of 5-10 degrees, enabling the pointed end of the blank pipe to be upward, soaking for 6-15 minutes, and moving the blank pipe up and down 2-3 times in the soaking process;
c. an oil inlet and an oil outlet are respectively arranged at two ends of the oil tank, a circulating pump is connected between the oil inlet and the oil outlet to circulate the drawing oil in the oil tank, the circulation amount of the drawing oil per hour is 30-40 tons, and compressed air is introduced into the bottom of the oil tank to carry out air stirring on the drawing oil;
d. detecting the water content in the oil groove at least once every day, supplementing water from an oil inlet of the oil groove and circulating along with drawing oil when the water content is lower than 0.8%, wherein the water supplementing speed is not more than 5L/h, and the daily water supplementing amount is 2-3L/m 3 ；
e. Measuring the acid value of the drawing oil in the oil groove at regular time, and supplementing the drawing oil in time according to the drawing oil amount in the oil groove;
s12, placing the blank pipe soaked with the drawing oil in an inclined groove at one side of an oil groove, draining, and refluxing the drained drawing oil to the oil groove;
s13, performing cold drawing on the blank pipe on a cold drawing machine, wherein the cold drawing speed is controlled to be 20-35m/min, and the tolerance of the outer diameter of the pipe is-0.03-0.05 mm;
and S14, straightening, detecting the flaw, cutting to length, inspecting, packaging and warehousing the cold-drawn welded pipe.
As a further improvement, the acid value of the drawing oil is determined in the following manner:
taking 1ml of drawing oil by a pipette, putting the drawing oil into a 300 ml conical flask, rinsing residual oil in the pipette into the conical flask by using an ethanol solution with the volume concentration of 95% to ensure that the volume of the solution in the conical flask reaches 40 +/-5 ml, and shaking the conical flask to uniformly mix the drawing oil and the 95% ethanol solution; dropping 1-2 drops of phenolphthalein indicator into the conical flask, then quickly titrating with 0.1mol/L KOH ethanol solution, recording the consumed KOH ethanol solution as A ml after the color changes from blue to deep red,
f is a correction factor, and M is the gram weight of 1ml of drawing oil; the correction factor F is detected and calibrated at least once a week and is calculated as follows: accurately transferring 10ml of 0.1mol/L KOH ethanol solution into a conical bottle, adding 50ml of distilled water and 10 drops of phenolphthalein indicator, titrating to be colorless by using 0.05mol/L sulfuric acid, recording the volume of consumed sulfuric acid as F, and updating a correction factor F = F × 0.1, wherein a new correction factor F is obtained in each test and then updated into a calculation formula of an acid value.
As a further improvement, in the step S9, the special gas generated by incomplete combustion of natural gas is subjected to a diversion treatment, 85% of the special gas is frozen and dehumidified to form a reducing gas which is blown in from an upstream position of the heat-preservation cooling section, 15% of the special gas is introduced into the inlet and the outlet to participate in combustion together with other natural gases, the heat generated by incomplete combustion of natural gas can be supplied to the preheating section for heating, and the heating section needs a higher temperature, so that the natural gas is directly used for completely completing heating, thereby ensuring that the heat energy is fully utilized, the quantity of the special gas generated by incomplete combustion of natural gas is large, therefore, a fire curtain is formed by supplying part of the special gas to the inlet and the outlet, and the other special gas participates in reduction of an oxide layer of the welded pipe as the reducing gas, and the special gas is more reasonably utilized.
As a further improvement, the blowing points for blowing the reducing gas from the upstream position of the heat-insulating cooling section are multiple and are uniformly distributed along the width direction of the heat-insulating cooling section, so that the reducing gas can be better distributed in the furnace body, and the reducing gas can be fully contacted with an oxide layer on the surface of the welded pipe and can be reduced.
As a further improvement, in the step e of step S11, the specific manner of measuring the acid value of the drawing oil in the oil bath at regular time and supplementing the drawing oil in time according to the amount of the drawing oil in the oil bath is as follows:
e1, when the acid number of the drawing oil is lower than 85 and higher than 70, directly supplementing the currently used drawing oil;
e2, when the acid value of the drawing oil is lower than 70, supplementing the drawing oil with the same composition as the current drawing oil but with the acid value between 95 and 110;
e3, and performing acid value measurement again after drawing oil is supplemented each time. The acid value can be quickly and effectively adjusted while drawing oil is supplemented through the step, the operation is simpler and more convenient, other components are not introduced during the adjustment of the acid value, and the adjustment of the acid value is simpler.
As a preferable scheme, the method for detecting the water content in S11 is as follows:
weighing 100 g of drawing oil in a beaker, adding the drawing oil into a round-bottom flask, using dimethylbenzene to wash the drawing oil remained in the beaker, pouring the drawing oil into the round-bottom flask after washing, using the dimethylbenzene in an amount of 200 +/-20 ml, slightly shaking the flask to be uniformly mixed with the drawing oil, adding a small amount of zeolite, and measuring the water content by a distillation method.
After the technical scheme is adopted, the invention has the effects that: 1. in the step S3, the inner and outer surfaces of the weld joint are deburred, and the height difference is negative, so that the length of the weld joint is lengthened due to plastic deformation of the metal of the welded pipe during cold drawing, and the outer diameter, the inner diameter and the wall thickness of the welded pipe can be changed after passing through a drawing die, so that the height difference of the inner and outer surfaces at the weld joint is negative, so that drawing is more convenient, crystals at the weld joint are not easy to accumulate during plastic deformation, the surface quality at the weld joint is higher, and the condition of metal folding or drawing marks is not easy to occur; 2. in the step S9, the rustproof blank tube is subjected to heat treatment in an atmosphere roller hearth furnace, and natural gas is introduced into an inlet of a combustion furnace and an outlet of a heat-preservation cooling section and is ignited to form a fire curtain during the heat treatment; so just with the oxygen consumption of entry and exit, the welded tube also can not be by oxidation when passing in and out, simultaneously, because the oxygen of entry and exit consumes all the time, the atmospheric pressure in the stove at entry and exit can reduce, makes the better follow furnace body of reducing gas and to both ends diffusion like this, the reducing gas in whole furnace body flows more smoothly also more evenly like this, can be better to welded tube tableReducing the oxide layer of the surface; in addition, the flow rate of the natural gas is 15-30 m 3 H: the flow rate of the air is 150-220 m 3 The incomplete reaction degree of the natural gas is accurately controlled, the volume percentage concentration of the carbon monoxide gas in the furnace is ensured to be 7.0-8.5%, and then the running speed of the blank pipe in the furnace is matched to be 0.8-1.2 m/min, so that the reduction reaction can be fully performed between the reducing gas and the welded pipe, and an oxide layer is more thoroughly removed; in addition, reducing gas is blown in from the upstream position of the heat-preservation cooling section and is diffused from the middle to the two sides, the flow route of the reducing gas is more reasonable, and the reducing gas in the furnace is more uniform; 3. in the step S11 of the forming method, the blank tube is soaked in the reactive drawing oil and the iron phosphating film is generated, because the acid value and the water content have influence on the film thickness and the reaction speed of the iron phosphating layer, the drawing oil is circulated and stirred, so that the drawing oil in the oil tank is as uniform as possible, different parts of each welded tube can be ensured to be soaked in the uniform drawing oil, meanwhile, the water amount and the drawing oil amount are supplemented by detecting the water content and the acid value of the oil tank, thus, the fluctuation of each component in the drawing oil is ensured to be small, the thickness of the iron phosphating film generated by the surface reaction of the drawing oil and the welded tube is uniform and consistent, and the surface roughness is better in the subsequent drawing step process.
Detailed Description
The present invention is described in further detail below by way of specific examples.
A cold-drawing forming method of a precision welded pipe comprises the following steps:
s1, cold rolling and cutting the formed steel plate to form a steel strip coil;
s2, forming the steel strip reel pipe and welding the steel strip reel pipe into a welded pipe through high-frequency welding;
s3, removing inner and outer burrs of the welding seam to form a blank pipe;
the process for removing the outer burrs of the welding seam comprises the following steps: removing burrs of an external welding seam of the welded pipe by using a hard alloy outer arc blade, wherein the mark of the hard alloy is YG15 or YG30, the outer surface of the removed welding seam is in smooth transition with other outer surfaces of the blank pipe, and the height difference is-0.03 to-0.02 mm, so that the outer surface of the welding seam is lower than the outer surface of the whole welded pipe;
the technology for removing burrs in the welding seam comprises the following steps: removing burrs of a welding seam in the welded pipe by using a titanium plating inner circular arc scraper with a hard alloy mark of YW1 or YW3, wherein the surface of the removed welding seam is smoothly and flatly transited with other inner surfaces of the blank pipe, and the height difference is-0.05 to-0.03 mm; similarly, the inner surface of the welding seam is lower than that of the whole welded pipe, so that the metal structure can generate plastic deformation in the subsequent drawing process conveniently, crystals at the welding seam are not easy to accumulate during the plastic deformation, the surface quality at the welding seam is higher, and the condition of metal folding or drawing marks is not easy to occur.
S4, sizing the blank pipe, wherein the tolerance of the outer diameter of the sized blank pipe is-0.20-0.2 mm;
s5, straightening the blank pipe, wherein the straightness of the blank pipe is 0.8-1.3 mm/m after the blank pipe is straightened by a straightening machine;
s6, soaking the blank tube in degreasing liquid for degreasing, wherein the degreasing temperature is controlled to be 75-85 ℃, and the free alkalinity of the degreasing liquid is 20-30; the preferable degreasing temperature is 80 ℃, and the soaking times are 3 times;
s7, cleaning the degreased blank pipe with clear water for two times;
s8, soaking the cleaned blank pipe into an antirust agent for antirust treatment, wherein the free alkalinity of the antirust agent is 2-4; the blank pipe needs to be completely soaked in the antirust agent, after the antirust agent is used for a period of time, when the antirust agent is turbid, the antirust agent is pumped into a sedimentation tank for sedimentation, and impurities precipitated at the bottom are subjected to environment-friendly treatment;
s9, carrying out heat treatment on the rustproof blank pipe in an atmosphere roller hearth furnace, wherein the specific method is as follows: the furnace body is divided into a preheating section, a heating section and a heat-preservation cooling section according to the process flow direction, natural gas and air are incompletely combusted in a combustion furnace, and the combustion furnace is used as the preheating section and is connected with an inlet of the heating section; the flow of the natural gas of the combustion furnace is 15-30 m 3 H: the flow rate of the air is 150-220 m 3 The volume percentage concentration of the carbon monoxide gas in the furnace is 7.0-8.5%, the running speed of the blank pipe in the furnace is 0.8-1.2 m/min, and the heating temperature is 550-650 ℃; is introduced into the inlet of the combustion furnace and the outlet of the heat-insulating cooling sectionIgniting natural gas to form a fire curtain;
the other path of natural gas and air are completely combusted to heat the radiant tube of the heating section to carry out heat treatment on the blank tube, the heating temperature is 720-740 ℃, special gas generated by incomplete combustion of the natural gas is frozen and dehumidified to form reducing gas, the reducing gas is blown in from the upstream position of the heat-preservation cooling section, and the temperature of the cooled reducing gas entering the furnace is 4-6 ℃; the heat-preservation cooling section of the furnace body adopts a water-cooling coil pipe to carry out heat exchange with the inside of the furnace to form a heat-preservation cooling section, and the heat-preservation cooling section adopts a stepped heat-preservation cooling section;
step S9, performing diversion processing on the special gas generated by incomplete combustion of the natural gas, forming a reducing gas by 85% of the special gas after freezing and dehumidifying and blowing in the reducing gas from the upstream position of the heat preservation cooling section, introducing 15% of the special gas into the inlet and the outlet to participate in combustion together with other natural gas, wherein the heat generated by incomplete combustion of the natural gas is the heat supplied to the preheating section of the furnace body, and the heating section is used for ensuring enough heat, and the natural gas is completely combusted, so that the utilization rate of the heat is higher. The blowing points of the reducing gas blown in from the upstream position of the heat preservation cooling section are a plurality of and are uniformly distributed along the width direction of the heat preservation cooling section, so that the reducing gas can be better distributed in the furnace body, and the surface of the welded pipe subjected to heat treatment in the atmosphere roller hearth furnace is bright and has no oxide layer.
S10, closing one end of the blank tube to form a tip convenient for cold drawing;
s11, soaking the blank tube into reactive drawing oil and generating an iron-based phosphating film, wherein the reactive drawing oil is drawing oil sold by Kyote chemical company of Shanghai, and the specific method comprises the following steps:
a. adding drawing oil with the water content of 0.8-1.5% by mass and the acid value of 70-90% into an oil groove, and heating the drawing oil in the oil groove by using a temperature control device to control the temperature to be 60-70 ℃;
b. obliquely soaking the blank pipe into drawing oil in an oil groove at an inclination angle of 5-10 degrees, enabling the pointed end of the blank pipe to be upward, soaking for 6-15 minutes, and moving the blank pipe up and down 2-3 times in the soaking process; the oil in the welded pipe is discharged as much as possible when the welded pipe is lifted up each time, so that the full reaction is facilitated.
c. An oil inlet and an oil outlet are respectively arranged at two ends of the oil tank, a circulating pump is connected between the oil inlet and the oil outlet to circulate the drawing oil in the oil tank, the circulation volume of the drawing oil per hour is 30-40 tons, and compressed air is introduced into the bottom of the oil tank to carry out air stirring on the drawing oil;
d. detecting the water content in the oil groove at least once every day, supplementing water from an oil inlet of the oil groove and circulating along with drawing oil when the water content is lower than 0.8%, wherein the water supplementing speed is not more than 5L/h, and the daily water supplementing amount is 2-3L/m 3 (ii) a The method for detecting the water content in S11 is as follows:
weighing 100 g of drawing oil in a beaker, adding the drawing oil into a round-bottom flask, using dimethylbenzene to wash the drawing oil remained in the beaker, pouring the drawing oil into the round-bottom flask after washing, using the dimethylbenzene in an amount of 200 +/-20 ml, slightly shaking the flask to be uniformly mixed with the drawing oil, adding a small amount of zeolite, and measuring the water content by a distillation method.
e. Measuring the acid value of the drawing oil in the oil groove at regular time, and supplementing the drawing oil in time according to the drawing oil amount in the oil groove;
the acid value of the drawing oil is determined in the following way:
taking 1ml of drawing oil by a pipette, putting the drawing oil into a 300 ml conical flask, rinsing residual oil in the pipette into the conical flask by using an ethanol solution with the volume concentration of 95% to ensure that the volume of the solution in the conical flask reaches 40 +/-5 ml, and shaking the conical flask to uniformly mix the drawing oil and the 95% ethanol solution; dropping 1-2 drops of phenolphthalein indicator into the conical flask, then quickly titrating with 0.1mol/L KOH ethanol solution, recording the consumed KOH ethanol solution as A ml after the color changes from blue to deep red,
f is a correction factor, M is the gram weight of 1ml of drawing oil(ii) a The correction factor F is detected and calibrated at least once a week and is calculated as follows: accurately transferring 10ml of 0.1mol/L KOH ethanol solution into a conical bottle, adding 50ml of distilled water and 10 drops of phenolphthalein indicator, titrating with 0.05mol/L sulfuric acid until colorless, recording the volume of consumed sulfuric acid as F, and updating a correction factor F = F multiplied by 0.1, wherein a new correction factor F is obtained in each test and then updated into a calculation formula of an acid value.
More preferably, in the step S11, the step e of measuring the acid value of the drawing oil in the oil bath at regular time and supplementing the drawing oil in time according to the amount of the drawing oil in the oil bath is as follows:
e1, when the acid number of the drawing oil is lower than 85 and higher than 70, directly supplementing the currently used drawing oil;
e2, when the acid value of the drawing oil is lower than 70, supplementing the drawing oil with the same composition as the current drawing oil but with the acid value between 95 and 110;
e3, and performing acid value measurement again after each drawing oil supplement. The acid value can be adjusted more quickly and effectively while drawing oil is supplemented through the step, and the operation is simpler and more convenient.
S12, placing the blank pipe soaked with the drawing oil in an inclined groove at one side of an oil groove for draining, and refluxing the drained drawing oil to the oil groove;
s13, performing cold drawing on the blank pipe on a cold drawing machine, wherein the cold drawing speed is controlled to be 20-35m/min, and the tolerance of the outer diameter of the pipe is-0.03-0.05 mm;
and S14, straightening, detecting the flaw, cutting to length, inspecting, packaging and warehousing the cold-drawn welded pipe.
According to the above method, the following examples were obtained at different water consumption, reaction time, acid value, film thickness and temperature by adjusting different parameters of the drawing oil in the case of welded pipes of the same specification.
Example 1
The embodiment adopts the aboveThe steel pipe produced by the cold-drawing forming method has the diameter of 27mm and the wall thickness of 1mm, the steel pipes produced by the following other examples have the same specification as the steel pipe produced by the embodiment, wherein the temperature of drawing oil is controlled at 60 ℃, the acid value of the drawing oil is 70, the water content of the drawing oil is 0.8%, the soaking reaction time of the steel pipe is 15 minutes, and after one day of continuous production flow, the water consumption is measured to be 2.3L/m 3 After the steel pipe is soaked in the drawing oil, the thickness of the oil film on the surface of the steel pipe is tested to be 0.18 mu m by using a commercially available film thickness tester, after the steel pipe is drawn, the steel pipe is tested in a room temperature environment by using a model SJ-210 portable surface roughness tester which is developed and produced by Sanfeng of Japan, the use mode of the specific roughness tester can be obtained from the use instruction of the commercially available model SJ-210 portable surface roughness tester, and the specific test mode of the roughness is as follows: the steel pipes of each specification and each batch are detected at least 1 time, two steel pipes are extracted each time, each steel pipe is divided into 5 detection points according to the length, the roughness is detected by 10 detection points in total, the average roughness is calculated to be used for measuring the roughness of the steel pipe, the average roughness of the steel pipe of the batch is 0.20 mu m after detection, the roughness test mode of other examples 2-9 is the same as that of the example 1, and the details are not repeated.
Example 2
The temperature of the drawing oil in this example was controlled at 60 ℃, the acid value of the drawing oil was 90, the water content was 1.0%, the time for the steel pipe soaking reaction was 10 minutes, and after one day of continuous production, the water consumption was 2.5L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.22 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 3
In this example, the temperature of the drawing oil was controlled at 60 ℃, the acid value of the drawing oil was 85, the water content was 1.5%, the time of the steel pipe immersion reaction was 11 minutes, and the water consumption was 2.4L/m as measured after one day of continuous production process 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.28 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 4
The temperature of the drawing oil in this example was controlled at 65 ℃, the acid value of the drawing oil was 70, the water content was 0.8%, the time for the steel pipe soaking reaction was 13 minutes, and after one day of continuous production, the water consumption was 2.6L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.18 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 5
The temperature of the drawing oil in this example was controlled at 65 ℃, the acid value of the drawing oil was 90, the water content was 1.0%, the time for the steel pipe soaking reaction was 9 minutes, and after one day of continuous production, the water consumption was 2.9L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.30 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 6
The temperature of the drawing oil in this example was controlled at 65 ℃, the acid value of the drawing oil was 85, the water content was 1.5%, the time for the steel pipe soaking reaction was 11 minutes, and after one day of continuous production, the water consumption was 2.7L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.32 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the thickness was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan K.K., to obtain the steel pipe of this exampleThe average roughness was 0.18. mu.m.
Example 7
In this example, the temperature of the drawing oil was controlled at 70 ℃, the acid value of the drawing oil was 70, the water content was 0.8%, the time of the steel pipe immersion reaction was 12 minutes, and the water consumption was 2.8L/m as measured after one day of continuous production process 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.20 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 8
The temperature of the drawing oil in this example was controlled at 70 ℃, the acid value of the drawing oil was 90, the water content was 1.0%, the time for the steel pipe soaking reaction was 8 minutes, and after one day of continuous production, the water consumption was 3.0L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.28 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a model SJ-210 portable surface roughness measuring instrument manufactured and developed by Sanfeng, Japan.
Example 9
The temperature of the drawing oil in this example was controlled at 70 ℃, the acid value of the drawing oil was 85, the water content was 1.5%, the time for the steel pipe soaking reaction was 10 minutes, and after one day of continuous production, the water consumption was 2.9L/m 3 After the steel pipe was immersed in the drawing oil, the thickness of the oil film on the surface of the steel pipe was measured to be 0.29 μm by a commercially available film thickness measuring instrument, and after the steel pipe was drawn, the average roughness of the steel pipe of this example was measured by a portable surface roughness measuring instrument model SJ-210, manufactured and developed by Sanfeng, Japan.
Comparative examples
The current conventional cold drawing method for phosphating containing pickling in the comparative example has the following specific production flow: carbon steel band-reelpipe shaping-high frequency weld seam welding-removing internal and external burrs of weld seam → sizing and shaping of blank pipe → weld seam eddy current inspection → straightening of blank pipe length → cutting to length of blank pipe to length → inspection → degreasing of blank pipe 1 → clear water cleaning 2 → drying → heat treatment → degreasing of blank pipe 2 → clear water cleaning 2 → acid cleaning → clear water cleaning 3 → neutralization → clear water cleaning 4 → surface conditioning → phosphating → clear water cleaning 5 → draining of blank pipe → drawing tip of blank pipe → soaking drawing oil → drawing of blank pipe → straightening of blank pipe → welding pipe straightening → eddy current inspection → cutting to length → inspection → packaging → warehousing, the drawing oil used by the production method is conventional drawing oil, and the roughness of 10 detection points obtained by the steel pipe after detection is respectively: 0.41 μm, 0.39 μm, 0.38 μm, 0.41 μm, 0.37 μm, 0.40 μm, 0.38 μm, 0.37 μm, 0.40 μm, 0.36 μm; the average roughness of the steel pipe is 0.39 mu m, so the roughness of the steel pipe formed by the conventional cold drawing method is much higher than that of the steel pipe formed by the method of the invention.
The parameters of the drawing oils according to the above examples 1 to 9 are collated in the following table:
from the above surface, it can be seen that the increase of the water content increases the thickness of the phosphate film, while the increase of the acid value allows the reaction time to be faster and the required soaking reaction time to be shorter; on the other hand, the film thickness is increased at the initial stage of temperature increase, but when the acid value is high due to temperature increase, the film thickness is rather decreased by the excessive water consumption, which is found by comparing example 8 with example 5 and comparing example 9 with example 6, and the subsequent cold drawing effect is also affected.
It can be found from examples 1 to 9 that 10 test data are detected in each example by the cold-drawing forming method of the present invention, the detected roughness data are less than 0.2 μm and even reach 0.18 μm except for examples 1, 8 and 9, and the roughness data are less than 0.2 μm or even reach 0.18 μm in each example, and the roughness data are equal to or less than 0.2 μm in each example 1 to 9 by the test of 90 test data in 9 batches, so the stability of the steel pipe obtained by the cold-drawing forming method of the present invention is very high.
Claims (6)
1. A cold-drawing forming method of a precision welded pipe is characterized by comprising the following steps: the method comprises the following steps:
s1, cold rolling and cutting the formed steel plate to form a steel strip coil;
s2, forming the steel strip reel pipe and welding the steel strip reel pipe into a welded pipe through high-frequency welding;
s3, removing inner and outer burrs of the welding seam to form a blank pipe;
the process for removing the outer burrs of the welding seam comprises the following steps: removing burrs of the outer welding seam of the welded pipe by using a hard alloy outer arc blade, wherein the removed outer surface of the welding seam is smoothly and smoothly transited with other outer surfaces of the blank pipe, and the height difference is-0.03 to-0.02 mm;
the removing process of burrs in the welding seam comprises the following steps: removing welding seam burrs in the welded pipe by using an inner circular arc scraper for titanium plating of hard alloy, wherein the removed welding seam surface is in smooth transition with other inner surfaces of the blank pipe, and the height difference is-0.05 to-0.03 mm;
s4, sizing the blank pipe, wherein the tolerance of the outer diameter of the sized blank pipe is-0.20-0.2 mm;
s5, straightening the blank pipe, wherein the straightness of the blank pipe is 0.8-1.3 mm/m after the blank pipe is straightened by a straightening machine;
s6, soaking the blank tube in degreasing liquid for degreasing, wherein the degreasing temperature is controlled to be 75-85 ℃, and the free alkalinity of the degreasing liquid is 20-30;
s7, washing the degreased blank pipe with clear water for two times;
s8, soaking the cleaned blank pipe into an antirust agent for rust prevention treatment, wherein the free alkalinity of the antirust agent is 2-4;
s9, carrying out heat treatment on the rustproof blank pipe in an atmosphere roller hearth furnace, wherein the specific method is as follows: the furnace body is divided into a preheating section, a heating section and a heat-preservation cooling section according to the process flow direction, natural gas and air are incompletely combusted in a combustion furnace, and the combustion furnace is used as the preheating section and is connected with an inlet of the heating section; the flow of the natural gas of the combustion furnace is 15-30 m 3 H: the flow rate of the air is 150-220 m 3 H, the volume percentage concentration of carbon monoxide gas in the furnace is 7.0-8.5%, and the blank tube isThe operation speed in the furnace is 0.8-1.2 m/min, and the heating temperature is 550-650 ℃; introducing natural gas into an inlet of the combustion furnace and an outlet of the heat-preservation cooling section and igniting the natural gas to form a fire curtain;
the other path of natural gas and air are completely combusted to heat the radiant tube of the heating section to carry out heat treatment on the blank tube, the heating temperature is 720-740 ℃, special gas generated by incomplete combustion of the natural gas is frozen and dehumidified to form reducing gas, the reducing gas is blown in from the upstream position of the heat-preservation cooling section, and the temperature of the cooled reducing gas entering the furnace is 4-6 ℃; the heat-preservation cooling section of the furnace body adopts a water-cooling coil pipe to exchange heat with the inside of the furnace to form a heat-preservation cooling section, and the heat-preservation cooling section adopts a stepped heat-preservation cooling section;
s10, closing one end of the blank tube to form a tip convenient for cold drawing;
s11, soaking the blank tube into reactive drawing oil to generate an iron-based phosphating film, wherein the specific method comprises the following steps:
a. adding drawing oil with the water content of 0.8-1.5% by mass and the acid value of 70-90% into an oil groove, and heating the drawing oil in the oil groove by using a temperature control device to control the temperature to be 60-70 ℃;
b. obliquely soaking the blank pipe into drawing oil in an oil groove at an inclination angle of 5-10 degrees, enabling the pointed end of the blank pipe to be upward, soaking for 6-15 minutes, and moving the blank pipe up and down 2-3 times in the soaking process;
c. an oil inlet and an oil outlet are respectively arranged at two ends of the oil tank, a circulating pump is connected between the oil inlet and the oil outlet to circulate the drawing oil in the oil tank, the circulation amount of the drawing oil per hour is 30-40 tons, and compressed air is introduced into the bottom of the oil tank to carry out air stirring on the drawing oil;
d. detecting the water content in the oil groove at least once every day, supplementing water from an oil inlet of the oil groove and circulating along with drawing oil when the water content is lower than 0.8%, wherein the water supplementing speed is not more than 5L/h, and the daily water supplementing amount is 2-3L/m 3 ；
e. Measuring the acid value of the drawing oil in the oil groove at regular time, and supplementing the drawing oil in time according to the drawing oil amount in the oil groove;
s12, placing the blank pipe soaked with the drawing oil in an inclined groove at one side of an oil groove, draining, and refluxing the drained drawing oil to the oil groove;
s13, performing cold drawing on the blank pipe on a cold drawing machine, wherein the cold drawing speed is controlled to be 20-35m/min, and the tolerance of the outer diameter of the pipe is-0.03-0.05 mm;
and S14, straightening, detecting the flaw, cutting to length, inspecting, packaging and warehousing the cold-drawn welded pipe.
2. The cold-drawing forming method of the precision welded pipe according to claim 1, characterized in that: the acid value of the drawing oil is determined in the following manner:
taking 1ml of drawing oil by a pipette, putting the drawing oil into a 300 ml conical flask, rinsing residual oil in the pipette into the conical flask by using an ethanol solution with the volume concentration of 95% to ensure that the volume of the solution in the conical flask reaches 40 +/-5 ml, and shaking the conical flask to uniformly mix the drawing oil and the 95% ethanol solution; dropping 1-2 drops of phenolphthalein indicator into the conical flask, then quickly titrating with 0.1mol/L KOH ethanol solution, recording the consumed KOH ethanol solution as A ml after the color changes from blue to deep red,
f is a correction factor, and M is the gram weight of 1ml of drawing oil; the correction factor F is detected and calibrated at least once a week and is calculated as follows: accurately transferring 10ml of 0.1mol/L KOH ethanol solution into a cone-shaped bottle, adding 50ml of distilled water and 10 drops of phenolphthalein indicator, titrating to be colorless by using 0.05mol/L sulfuric acid, recording the volume of consumed sulfuric acid as F, and updating a correction factor F = F multiplied by 0.1 into a calculation formula of an acid value after each test to obtain a new correction factor F.
3. A cold-drawing forming method of a precision welded pipe according to claim 2, characterized in that: and S9, carrying out shunting treatment on the special gas generated by incomplete combustion of the natural gas, wherein 85% of the special gas is frozen and dehumidified to form reducing gas to be blown in from the upstream position of the heat-preservation cooling section, and 15% of the special gas is introduced into the inlet and the outlet to participate in combustion together with other natural gas.
4. A cold-drawing forming method for a precision welded pipe according to claim 3, characterized in that: the blowing points of the reducing gas blown in from the upstream position of the heat preservation cooling section are multiple and are uniformly distributed along the width direction of the heat preservation cooling section.
5. The cold-drawing forming method of the precision welded pipe according to claim 4, characterized in that: in the step e of the step S11, the specific manner of measuring the acid value of the drawing oil in the oil groove at regular time and supplementing the drawing oil in time according to the drawing oil amount in the oil groove is as follows:
e1, when the acid number of the drawing oil is lower than 85 and higher than 70, directly supplementing the currently used drawing oil;
e2, when the acid value of the drawing oil is lower than 70, supplementing the drawing oil with the same composition as the current drawing oil but with the acid value between 95 and 110;
e3, and performing acid value measurement again after each drawing oil supplement.
6. The cold-drawing forming method of the precision welded pipe according to claim 5, characterized in that: the method for detecting the water content in S11 is as follows:
weighing 100 g of drawing oil in a beaker, adding the drawing oil into a round-bottom flask, using dimethylbenzene to wash the drawing oil remained in the beaker, pouring the drawing oil into the round-bottom flask after washing, wherein the using amount of the dimethylbenzene is 200 +/-20 ml, slightly shaking the flask to be uniformly mixed with the drawing oil, adding a small amount of zeolite, and measuring the water content by a distillation method.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115351519A (en) * | 2022-10-20 | 2022-11-18 | 江苏银环精密钢管有限公司 | Preparation method of inner cylinder for heat exchange unit of high-temperature gas cooled reactor evaporator |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3710428A (en) * | 1971-06-09 | 1973-01-16 | Reed Mfg Co | Plastic pipe flaring tool |
| CN1406681A (en) * | 2001-08-30 | 2003-04-02 | 隆昌山川精密焊管有限责任公司 | Cold drawing precisive pipe for electrically welding magneto casing of car |
| CN102527767A (en) * | 2011-11-22 | 2012-07-04 | 玛切嘉利（中国）有限责任公司 | Cold drawing welded tube manufacture process for high-accuracy hydraulic oil cylinder |
| CN103894798A (en) * | 2014-03-31 | 2014-07-02 | 张家港保税区亚信汽车零部件科技有限公司 | Manufacturing method of precisely-welded pipe |
| CN103921066A (en) * | 2014-03-18 | 2014-07-16 | 泰州双羊精密无缝钢管有限公司 | Method for manufacturing seamless steel pipes for shock absorbers |
| CN104455168A (en) * | 2014-11-24 | 2015-03-25 | 张家港保税区亚信汽车零部件科技有限公司 | Low friction cylinder of shock absorber and manufacturing method thereof |
| CN104646932A (en) * | 2013-11-16 | 2015-05-27 | 无锡大金高精度冷拔钢管有限公司 | Manufacturing method for high-precision cold-drawing welded pipe |
| CN104646449A (en) * | 2013-11-16 | 2015-05-27 | 无锡大金高精度冷拔钢管有限公司 | Manufacturing method for cold drawn welded pipe used for hydraulic oil cylinders |
| CN105567392A (en) * | 2015-12-23 | 2016-05-11 | 南京科润工业介质股份有限公司 | Drawing lubricant oil |
| CN106093290A (en) * | 2016-07-27 | 2016-11-09 | 湖北富邦科技股份有限公司 | A kind of qualitative determination method that anti-caking agent dispensing is the most correct |
-
2022
- 2022-08-25 CN CN202211022529.4A patent/CN115091147A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3710428A (en) * | 1971-06-09 | 1973-01-16 | Reed Mfg Co | Plastic pipe flaring tool |
| CN1406681A (en) * | 2001-08-30 | 2003-04-02 | 隆昌山川精密焊管有限责任公司 | Cold drawing precisive pipe for electrically welding magneto casing of car |
| CN102527767A (en) * | 2011-11-22 | 2012-07-04 | 玛切嘉利（中国）有限责任公司 | Cold drawing welded tube manufacture process for high-accuracy hydraulic oil cylinder |
| CN104646932A (en) * | 2013-11-16 | 2015-05-27 | 无锡大金高精度冷拔钢管有限公司 | Manufacturing method for high-precision cold-drawing welded pipe |
| CN104646449A (en) * | 2013-11-16 | 2015-05-27 | 无锡大金高精度冷拔钢管有限公司 | Manufacturing method for cold drawn welded pipe used for hydraulic oil cylinders |
| CN103921066A (en) * | 2014-03-18 | 2014-07-16 | 泰州双羊精密无缝钢管有限公司 | Method for manufacturing seamless steel pipes for shock absorbers |
| CN103894798A (en) * | 2014-03-31 | 2014-07-02 | 张家港保税区亚信汽车零部件科技有限公司 | Manufacturing method of precisely-welded pipe |
| CN104455168A (en) * | 2014-11-24 | 2015-03-25 | 张家港保税区亚信汽车零部件科技有限公司 | Low friction cylinder of shock absorber and manufacturing method thereof |
| CN105567392A (en) * | 2015-12-23 | 2016-05-11 | 南京科润工业介质股份有限公司 | Drawing lubricant oil |
| CN106093290A (en) * | 2016-07-27 | 2016-11-09 | 湖北富邦科技股份有限公司 | A kind of qualitative determination method that anti-caking agent dispensing is the most correct |
Non-Patent Citations (3)
| Title |
|---|
| 刘峰璧: "《机械设备润滑》", 31 October 2015 * |
| 曹凤云: "《食品理化检验技术》", 31 August 2016 * |
| 王华等: "《加热炉》", 30 September 2015 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115351519A (en) * | 2022-10-20 | 2022-11-18 | 江苏银环精密钢管有限公司 | Preparation method of inner cylinder for heat exchange unit of high-temperature gas cooled reactor evaporator |
| CN115351519B (en) * | 2022-10-20 | 2023-08-22 | 江苏银环精密钢管有限公司 | Preparation method of inner cylinder for heat exchange unit of high-temperature gas cooled reactor evaporator |
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