CN111482483A - Stainless steel seamless tube cold rolling production line and production process - Google Patents

Abstract

The invention belongs to the technical field of stainless steel seamless tube cold rolling production, in particular to a stainless steel seamless tube cold rolling production line and a production process, which comprises the following steps of sequentially and continuously carrying out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery; the process for producing and processing the stainless steel seamless tube by adopting the cold rolling production process provided by the invention has the advantages of simple and reasonable process, convenience in operation, manpower and material resource saving, reusability of the tube head part after cutting, production cost reduction, improvement of the processing quality and the processing efficiency of the stainless steel seamless tube product by adopting the reasonable process, unnecessary loss saving and enhancement of the quality of a finished product produced and processed by the stainless steel seamless tube.

Description

Stainless steel seamless tube cold rolling production line and production process

Technical Field

The invention belongs to the technical field of stainless steel seamless tube cold rolling production, and particularly relates to a stainless steel seamless tube cold rolling production line and a production process.

Background

Stainless seamless pipe is a long steel material having a hollow cross section and no seam at the periphery. The thicker the wall thickness of the product is, the more economical and practical it is, and the thinner the wall thickness is, the more the processing cost thereof is greatly increased. The process of the product determines the limiting performance of the product, and the precision of a common seamless steel pipe is low: the wall thickness is not uniform, the brightness of the inner surface and the outer surface of the pipe is low, the sizing cost is high, the hard spots and the black spots on the inner surface and the outer surface are not easy to remove, and the detection and the shaping of the device need to be processed off line. Hot rolling, hot extrusion and cold rolling (rolling) stainless steel pipes according to a rolling method; the semi-ferrite semi-martensite stainless steel seamless pipe, the austenite stainless steel seamless pipe and the austenite-ferrite stainless steel seamless pipe are divided according to different stainless steel metallographic structures.

The prior stainless steel seamless pipe is produced and processed in a cold rolling mode, the working procedure is simpler, and the forming efficiency of pipe products is lower.

Therefore, the technical field provides a stainless steel seamless tube cold rolling production line and a production process, so as to solve the problems in the background.

Disclosure of Invention

To solve the problems set forth in the background art described above. The invention provides a stainless steel seamless tube cold rolling production line and a production process, and has the characteristics of simple and reasonable structure, convenience in use, simplicity in operation, high forming efficiency, good finished product quality and low production cost.

In order to achieve the purpose, the invention provides the following technical scheme: the cold rolling production process of the stainless steel seamless pipe comprises the following steps which are sequentially and continuously carried out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery.

Preferably, the pickling operation requires the following:

s2.1, preparing acid solution

Distribution of pickling baths: from front to back, a No. 1 common acid pool, a No. 2 common acid pool and a No. 3 whitening pool are respectively arranged;

s2.1.1, acid liquor proportioning ratio and pickling bath temperature: hydrofluoric acid: nitric acid = 2: 3. 70% of aqueous solution, 30% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 25-50 ℃ and a whitening pool: hydrofluoric acid: nitric acid = 1: 2. 50% of aqueous solution, 50% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 20-40 ℃;

s2.1.2, preparing the acid solution once every 3 days in the common acid tank, and preparing the acid solution once every 10-15 days in the albino tank;

s2.1.3, when the pH value of the acid solution is more than 3 or the oxide skin and dirt on the surface of the steel pipe or the pipe fitting can not be washed cleanly, preparing a new solution;

s2.1.4, thoroughly cleaning the acid mud in the acid pool every month;

s2.2, acid washing

S2.2.1, before the steel pipe and the pipe fitting are put into a cylinder, the solution is stirred uniformly, then the steel pipe and the pipe fitting are obliquely put into the cylinder to be soaked in a head-to-tail manner, the soaking time of the steel pipe and the pipe fitting is different according to different acid liquor concentrations, the steel pipe and the pipe fitting are lifted out in a head-to-tail manner when being lifted, residual floating oil stains and the like on the surface are washed in time by clear water, the surface quality is checked, and no black spots exist on the surface;

s2.2.2 soaking time of steel pipe and pipe fitting

Acid washing and oil removal: soaking in the new acid solution for 6-8 hours, and lifting the old acid solution for 8-12 hours;

whitening: soaking in new acid liquor for 3-4 hours, and lifting old acid liquor for 4-6 hours;

s2.2.3, the steel pipe and pipe fittings after acid cleaning and whitening must be five, namely no peracid, no acid deficiency, no oil, no lime and no residual acid, and the oil removal is realized without dripping water to form beads;

s2.2.4, washing the steel pipe until the inner wall is free of scale, dirt and residual acid, and the pressure of high-pressure water is more than 6 atmospheric pressures;

s2.3, plastering

S2.3.1 mixing mortar

Selecting high-quality quicklime, screening by using a 40-50-mesh sieve, precipitating by using water, drying to eighty percent, uniformly stirring with 3# industrial fat to form a colloidal state, and then adding water to dilute into a slurry state;

s2.3.2, plastering

S2.3.3 coating the inner wall of the tube with core diameter, drying, and coating the outer wall; the outer wall of the tube with the outer diameter is coated and then dried.

S2.3.4, when coating, the inner and outer surface coatings should be thin and uniform, not allowing to flow or block;

s2.4, drying

S2.4.1, the furnace numbers are clearly distinguished during air drying, the messy stack air drying is avoided, and the furnace numbers are layered according to different furnace numbers, with the high heads and the low tails, so as to facilitate the water flowing out.

Preferably, the pipe head treatment comprises pipe drawing and pipe drawing joint.

Preferably, the pipe drawing and heading operation comprises the following steps:

s3.1, preparation: when the head is punched, the size of the head meets the technological requirements, the length of the head is 120-150 mm, and the shoulder of the head after punching is required to be smooth and have no edges and corners;

s3.2, selecting: the tail end of the pierced billet is headed, and the end with poor quality is headed when the product is produced;

s3.3, standard: the steel pipe with the core drawing diameter needs to be perforated in the shoulder transition area, and the perforation size is based on air permeability, and the smaller the perforation size is, the better the perforation size is;

s3.4, requiring: when heating, strictly controlling temperature, loading materials frequently, turning materials frequently, heating quickly, beating quickly and cooling quickly;

s3.5, temperature control: the heating temperature of the head is 1050-1100 ℃, and the cooling mode is air cooling;

s3.6, heating requirement: the head is inserted into the heating hole and heated, the insertion depth is about 200mm, and the heating temperature is preferably red when the head is observed by naked eyes.

Preferably, the pipe joint pulling operation comprises the following steps:

s4.1, selecting a joint: selecting an old pipe head or a new pipe head which is suitable for the corresponding specification, and welding the old pipe head or the new pipe head to one end of a pierced billet or a product pipe;

s4.2, standard: the welded end should be cut flush, the edge is smooth and has circular arc, after welding, the welding seam should be lower than the external diameter of the tube, in order to prevent from contacting the drawing die while drawing, and require sufficient intensity, in order to avoid breaking;

and S4.3, cutting off the head every time after the drawing is finished, wherein the welding head can be repeatedly used.

Preferably, the cold rolling operation is as follows:

s6.1, before production, oil filling and heat engine are carried out according to equipment operation rules, and the equipment is piled according to equipment point inspection requirements for point inspection;

s6.2, checking the steel type, the furnace number, the specification and the count of the incoming material according to the data on the production flow list, and recording the data on the production flow list;

s6.3, before the steel pipe is loaded on a rolling mill, the inner hole of the steel pipe needs to be filled with oil, when the oil is filled, one end of the steel pipe is higher and the other end of the steel pipe is lower, the oil is filled from the higher end and flows out from the lower end, and the steel pipe is turned over, so that the oil is applied to the periphery of the inner hole of the;

s6.4, when the first steel pipe is rolled, one steel pipe with the same specification is used as a guide in the front clamp, the size tolerance must be measured and the surface quality must be checked when the hole pattern of the rolled steel pipe is rolled out, and when the size tolerance does not meet the requirement, the distance between the rollers and the position of the top head need to be adjusted to enable the rollers to meet the requirement of the tolerance;

s6.5, when the rolling mill is started, slowly accelerating from a slow speed, and strictly prohibiting direct starting at a high speed;

s6.6, during rolling, the rolling speed and the feeding amount of the tube blank need to be mastered, the main motor is generally controlled at about 500 revolutions per minute, the frame reciprocates for about 70-80 times per minute and 6-10mm per time, overspeed is strictly prohibited, and the feeding amount is strictly prohibited from increasing;

s6.7, during rolling, paying attention to the surface quality of the rolled steel pipe at any time, and not allowing the existence of bamboo joints, rolled burrs, rolled folds and lugs, finding the problems to stop immediately, finding out reasons and solving the problems, wherein if the hole pattern is found to be defective, personnel with rich experience and high technical level must repair the steel pipe to ensure that the steel pipe meets the quality requirement;

s6.8, when the hole patterns are repaired, adjusted, disassembled and assembled, the main power supply is cut off, the machine can be started, and the work is strictly forbidden;

and S6.9, finishing rolling, checking the surface quality and counting the counts, filling and writing a production flow list and a process control record, and well performing field civilized production work.

Preferably, the heat treatment of the pipe fitting adopts solid hot melting treatment, and the operation method of the solid hot melting treatment comprises the following steps:

s7.1, the inner surface and the outer surface of the steel pipe subjected to solution treatment are required to be clean without residual acid, residual oil, residual lime and dirt, otherwise, the steel pipe can be subjected to solution treatment after being deoiled and cleaned again;

s7.2, checking whether the gas burners are blocked one by one, checking whether pipeline valves are opened flexibly, whether a fan and a water pump work normally, and confirming whether control instruments such as a flow meter, a pressure meter and a thermometer display normally one by one;

s7.3, after the furnace bottom conveying pipeline is pulled by hands, testing the furnace bottom conveying pipeline for 3 minutes under an empty load, and checking whether the stepless speed regulation of the furnace bottom conveying roller way is normal or not;

and S7.4, firstly opening 1-2 burners to heat the furnace body, simultaneously starting a furnace bottom roller way, feeding the steel pipe for heating when the temperature of the furnace reaches above 800 ℃, increasing the burners according to the heating speed of the steel pipe, controlling the running speed of the steel pipe, and ensuring the solid solution temperature and time of the steel pipe.

Preferably, the straightening operation is as follows:

s8.1, before starting, checking whether the straightener is normal, adding a proper amount of lubricating oil, and starting the straightener empty for one minute under the condition that the equipment is good so as to observe the running condition;

s8.2, the bending degree of the incoming material pipe cannot be too large, otherwise, manual initial correction is applied, and the material is added and straightened under the condition that the equipment capacity requirement is met;

s8.3, during straightening, adjusting the inclination angle of the straightening roller, the roller distance of the straightening roller and the position of the second pair of rollers, and simultaneously, correctly installing and adjusting an inlet guide plate to ensure the straightening quality;

s8.4, during straightening, spiral dents, straightening squares and straightening feathers are not allowed to be generated, and the dimension of the finished product pipe is not allowed to be corrected to be unqualified;

s8.5, properly widening the cold-rolled pipe according to the bending degree of the straightened pipe, wherein the core diameter pipe is not more than 15 mm/m;

s8.6, keeping the straightening roller clean, finding the conditions of fluffing, damage, iron adhesion and the like of the roller surface, and timely polishing the roller surface by using sand paper or a grinding wheel, and if the straightening quality is influenced by serious defects, timely replacing the roller;

and S8.7, carrying out the large-caliber steel pipe on a three-point type simple straight straightening machine.

Preferably, the operation method of cutting the tube is as follows:

s9.1, checking the cutting equipment and keeping a good running state;

s9.2, cutting the head, the tail or the length into a defined fixed length according to the standard requirement;

s9.3, when the head of the product is cut, the head of the product can be left with an old pipe head of 80-120mm, and when the head of the large-caliber pipe is cut, the head of the large-caliber pipe must be completely cut, neat and flat, so that the pipe head can be welded conveniently;

s9.4, when the end of the finished product is cut and the tail is cut, the pipe head is completely cut, the part with uneven wall thickness at the tail is completely cut, and metal is saved;

s9.5, removing burrs at two ends of the cut pipe by using a file or a grinding wheel, and blowing off carborundum in the pipe by using compressed air;

s9.6, after the products are cut, sending the cut products to a headed steel pipe, wherein the headed end is arranged at one end and is arranged in order; sending to the acid-washed pipe, and arranging one end of the pipe;

s9.7, placing the cut pipe head, the cut pipe tail and the waste products in a waste pile according to steel types to prevent steel mixing.

Stainless steel seamless pipe cold rolling production line includes the following equipment that sets gradually along product direction of delivery:

acid pickling equipment: a pickling tank is adopted for pickling pierced billets;

drying equipment: the method adopts a drying furnace for drying the pierced billet;

the on-line heading equipment comprises: the method adopts a heading machine for heading the pierced billet;

online piecing equipment: the method adopts a welding machine for jointing pierced billets;

cold rolling equipment: the method adopts a cold rolling mill for cold rolling the pierced billet;

and (3) heat treatment equipment: the method adopts a solid solution machine for carrying out heat treatment on the pierced billet;

grinding equipment: the method adopts a grinding machine for grinding the pierced billet;

straightening equipment: the method adopts a straightening machine for straightening the pierced billet;

cutting equipment: the cutting machine is used for cutting the product pipe fitting;

polishing equipment: the polishing machine is used for polishing the product pipe fitting;

a marking device: the marking machine is used for marking and classifying the product pipe fittings;

packaging equipment: the packaging machine is used for packaging the product pipe fitting;

conveying equipment: which employs a conveyor belt for conveying the product tubes.

Compared with the prior art, the invention has the beneficial effects that:

the process for producing and processing the stainless steel seamless tube by adopting the cold rolling production process provided by the invention has the advantages of simple and reasonable process, convenience in operation, manpower and material resource saving, reusability of the tube head part after cutting, production cost reduction, improvement of the processing quality and the processing efficiency of the stainless steel seamless tube product by adopting the reasonable process, unnecessary loss saving and enhancement of the quality of a finished product produced and processed by the stainless steel seamless tube.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic flow structure diagram of the cold rolling production process of the present invention;

FIG. 2 is a schematic diagram showing the air-drying time of different steel pipes and pipe fittings in the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Referring to fig. 1-2, the present invention provides the following technical solutions: the cold rolling production process of the stainless steel seamless pipe comprises the following steps which are sequentially and continuously carried out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery.

Specifically, the pickling operation requires the following:

s2.1, preparing acid solution

Distribution of pickling baths: from front to back, a No. 1 common acid pool, a No. 2 common acid pool and a No. 3 whitening pool are respectively arranged;

s2.1.1, acid liquor proportioning ratio and pickling bath temperature: hydrofluoric acid: nitric acid = 2: 3. 70% of aqueous solution, 30% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 25 ℃ and a whitening pool: hydrofluoric acid: nitric acid = 1: 2. 50% of aqueous solution, 50% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 20 ℃;

s2.1.2, preparing the acid solution once every 3 days in the common acid tank, and preparing the acid solution once every 10 days in the whitening tank;

s2.1.3, when the pH value of the acid solution is more than 3 or the oxide skin and dirt on the surface of the steel pipe or the pipe fitting can not be washed cleanly, preparing a new solution;

s2.1.4, thoroughly cleaning the acid mud in the acid pool every month;

s2.2, acid washing

S2.2.1, before the steel pipe and the pipe fitting are put into a cylinder, the solution is stirred uniformly, then the steel pipe and the pipe fitting are obliquely put into the cylinder to be soaked in a head-to-tail manner, the soaking time of the steel pipe and the pipe fitting is different according to different acid liquor concentrations, the steel pipe and the pipe fitting are lifted out in a head-to-tail manner when being lifted, residual floating oil stains and the like on the surface are washed in time by clear water, the surface quality is checked, and no black spots exist on the surface;

s2.2.2 soaking time of steel pipe and pipe fitting

Acid washing and oil removal: soaking in new acid solution for 6 hr, and lifting old acid solution for 8 hr;

whitening: soaking in new acid solution for 3 hr, and lifting old acid solution for 4 hr;

s2.2.3, the steel pipe and pipe fittings after acid cleaning and whitening must be five, namely no peracid, no acid deficiency, no oil, no lime and no residual acid, and the oil removal is realized without dripping water to form beads;

s2.2.4, washing the steel pipe until the inner wall is free of scale, dirt and residual acid, and the pressure of high-pressure water is more than 6 atmospheric pressures;

s2.3, plastering

S2.3.1 mixing mortar

Selecting high-quality quicklime, screening by a 40-mesh sieve, precipitating with water until the quicklime is dried to eighty percent, uniformly mixing with 3# industrial fat to form a colloidal state, and then adding water to dilute the colloidal state to a slurry state;

s2.3.2, plastering

S2.3.3 coating the inner wall of the tube with core diameter, drying, and coating the outer wall; the outer wall of the tube with the outer diameter is coated and then dried.

S2.3.4, when coating, the inner and outer surface coatings should be thin and uniform, not allowing to flow or block;

s2.4, drying

S2.4.1, the furnace numbers are clearly distinguished during air drying, the messy stack air drying is avoided, and the furnace numbers are layered according to different furnace numbers, with the high heads and the low tails, so as to facilitate the water flowing out.

Specifically, the pipe head treatment comprises pipe drawing and head beating and pipe drawing joints, wherein for a pierced billet with the outer diameter less than or equal to phi 65mm or a steel pipe in a product, the pipe drawing and head beating are carried out; for the pierced billet with the outer diameter larger than phi 65mm or the steel pipe in the product, a drawing head can be welded by adopting a sub-arc welding method.

Specifically, the pipe-drawing and heading operation comprises the following steps:

s3.1, preparation: when the head is beaten, the size of the head meets the process requirements, the length of the head is 120mm, and the shoulder of the head after beating is required to be smooth and have no edges and corners;

s3.2, selecting: the tail end of the pierced billet is headed, and the end with poor quality is headed when the product is produced;

s3.3, standard: the steel pipe with the core drawing diameter needs to be perforated in the shoulder transition area, and the perforation size is based on air permeability, and the smaller the perforation size is, the better the perforation size is;

s3.4, requiring: when heating, strictly controlling temperature, loading materials frequently, turning materials frequently, heating quickly, beating quickly and cooling quickly;

s3.5, temperature control: the heating temperature of the head is 1050 ℃, and the cooling mode is air cooling;

s3.6, heating requirement: the head is inserted into the heating hole and heated, the insertion depth is about 200mm, and the heating temperature is preferably red when the head is observed by naked eyes.

Specifically, the pipe joint pulling operation comprises the following steps:

s4.1, selecting a joint: selecting an old pipe head or a new pipe head which is suitable for the corresponding specification, and welding the old pipe head or the new pipe head to one end of a pierced billet or a product pipe;

s4.2, standard: the welded end should be cut flush, the edge is smooth and has circular arc, after welding, the welding seam should be lower than the external diameter of the tube, in order to prevent from contacting the drawing die while drawing, and require sufficient intensity, in order to avoid breaking;

and S4.3, cutting off the head every time after the drawing is finished, wherein the welding head can be repeatedly used.

Specifically, the cold rolling operation process is as follows:

s6.1, before production, oil filling and heat engine are carried out according to equipment operation rules, and the equipment is piled according to equipment point inspection requirements for point inspection;

s6.2, checking the steel type, the furnace number, the specification and the count of the incoming material according to the data on the production flow list, and recording the data on the production flow list;

s6.3, before the steel pipe is loaded on a rolling mill, the inner hole of the steel pipe needs to be filled with oil, when the oil is filled, one end of the steel pipe is higher and the other end of the steel pipe is lower, the oil is filled from the higher end and flows out from the lower end, and the steel pipe is turned over, so that the oil is applied to the periphery of the inner hole of the;

s6.4, when the first steel pipe is rolled, a steel pipe with the same specification (the same as the rolling specification) is used as a guide in the front clamp, the size tolerance must be measured and the surface quality needs to be checked when the hole pattern of the steel pipe is rolled out, and when the size tolerance does not meet the requirement, the distance between the rollers and the position of the top head need to be adjusted to enable the rollers to meet the requirement of the tolerance;

s6.5, when the rolling mill is started, slowly accelerating from a slow speed, and strictly prohibiting direct starting at a high speed;

s6.6, during rolling, the rolling speed and the feeding amount of a tube blank need to be mastered, the main motor is generally controlled at about 500 revolutions per minute, the frame reciprocates for about 70 times per minute and 6mm per time (the deformation is large, the feeding amount is small, the deformation is small, and the feeding amount is large) and the over speed is strictly forbidden and the feeding amount is strictly forbidden to be increased;

s6.7, during rolling, paying attention to the surface quality of the rolled steel pipe at any time (special oil wiping workers are needed to be provided, and the surface quality is checked at the same time), and the existence of bamboo joint shapes, rolling burrs, rolling folds and lugs is not allowed, so that the steel pipe is immediately stopped, the reasons are found and solved, and if the defects of the hole pattern are found, people with rich experience and high technical level need to grind the steel pipe to enable the steel pipe to meet the quality requirement;

s6.8, when the hole patterns are repaired, adjusted, disassembled and assembled, the main power supply is cut off, the machine can be started, and the work is strictly forbidden;

and S6.9, finishing rolling, checking the surface quality and counting the counts, filling and writing a production flow list and a process control record, and well performing field civilized production work.

Specifically, the heat treatment of the pipe fitting adopts solid hot melting treatment, and the operation method of the solid hot melting treatment comprises the following steps:

s7.1, the inner surface and the outer surface of the steel pipe subjected to solution treatment are required to be clean without residual acid, residual oil, residual lime and dirt, otherwise, the steel pipe can be subjected to solution treatment after being deoiled and cleaned again;

s7.2, checking whether the gas burners are blocked one by one, checking whether pipeline valves are opened flexibly, whether a fan and a water pump work normally, and confirming whether control instruments such as a flow meter, a pressure meter and a thermometer display normally one by one;

s7.3, after the furnace bottom conveying pipeline is pulled by hands, testing the furnace bottom conveying pipeline for 3 minutes under an empty load, and checking whether the stepless speed regulation of the furnace bottom conveying roller way is normal or not;

and S7.4, opening 1 burner top heating furnace body firstly, starting a furnace bottom roller way simultaneously, feeding the steel pipe for heating when the temperature of the furnace reaches above 800 ℃, increasing the burners according to the heating speed of the steel pipe, controlling the running speed of the steel pipe, and ensuring the solid solution temperature and time of the steel pipe.

Specifically, the straightening operation method comprises the following steps:

s8.1, before starting, checking whether the straightener is normal, adding a proper amount of lubricating oil, and starting the straightener empty for one minute under the condition that the equipment is good so as to observe the running condition;

s8.2, the bending degree of the incoming material pipe cannot be too large, otherwise, manual initial correction is applied, and the material is added and straightened under the condition that the equipment capacity requirement is met;

s8.3, during straightening, adjusting the inclination angle of the straightening roller, the roller distance of the straightening roller and the position of the second pair of rollers, and simultaneously, correctly installing and adjusting an inlet guide plate to ensure the straightening quality;

s8.4, during straightening, spiral dents, straightening squares and straightening feathers are not allowed to be generated, and the dimension of the finished product pipe is not allowed to be corrected to be unqualified;

s8.5, properly widening the cold-rolled pipe according to the bending degree of the straightened pipe, wherein the core diameter pipe is not more than 15 mm/m;

s8.6, keeping the straightening roller clean, finding the conditions of fluffing, damage, iron adhesion and the like of the roller surface, and timely polishing the roller surface by using sand paper or a grinding wheel, and if the straightening quality is influenced by serious defects, timely replacing the roller;

and S8.7, carrying out the large-caliber steel pipe on a three-point type simple straight straightening machine.

Specifically, the operation method of cutting the pipe is as follows:

s9.1, checking the cutting equipment and keeping a good running state;

s9.2, cutting the head, the tail or the length into a defined fixed length according to the standard requirement;

s9.3, when the head of the product is cut, the head of the product can be left with an old pipe head of 80mm, and when the head of the large-diameter pipe is cut, the head of the large-diameter pipe must be completely cut, cut evenly and cut flatly, so that the pipe head can be welded conveniently;

s9.4, when the end of the finished product is cut and the tail is cut, the pipe head is completely cut, the part with uneven wall thickness at the tail is completely cut, and metal is saved;

s9.5, removing burrs at two ends of the cut pipe by using a file or a grinding wheel, and blowing off carborundum in the pipe by using compressed air;

s9.6, after the products are cut, sending the cut products to a headed steel pipe, wherein the headed end is arranged at one end and is arranged in order; sending to the acid-washed pipe, and arranging one end of the pipe;

s9.7, placing the cut pipe head, the cut pipe tail and the waste products in a waste pile according to steel types to prevent steel mixing.

Example 2

Referring to fig. 1-2, the present invention provides the following technical solutions: the cold rolling production process of the stainless steel seamless pipe comprises the following steps which are sequentially and continuously carried out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery.

Specifically, the pickling operation requires the following:

s2.1, preparing acid solution

Distribution of pickling baths: from front to back, a No. 1 common acid pool, a No. 2 common acid pool and a No. 3 whitening pool are respectively arranged;

s2.1.1, acid liquor proportioning ratio and pickling bath temperature: hydrofluoric acid: nitric acid = 2: 3. 70% of aqueous solution, 30% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 50 ℃ and a whitening pool: hydrofluoric acid: nitric acid = 1: 2. 50% of aqueous solution, 50% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 40 ℃;

s2.1.2, preparing the acid solution once every 3 days in the common acid tank, and preparing the acid solution once every 15 days in the whitening tank;

s2.1.3, when the pH value of the acid solution is more than 3 or the oxide skin and dirt on the surface of the steel pipe or the pipe fitting can not be washed cleanly, preparing a new solution;

s2.1.4, thoroughly cleaning the acid mud in the acid pool every month;

s2.2, acid washing

S2.2.1, before the steel pipe and the pipe fitting are put into a cylinder, the solution is stirred uniformly, then the steel pipe and the pipe fitting are obliquely put into the cylinder to be soaked in a head-to-tail manner, the soaking time of the steel pipe and the pipe fitting is different according to different acid liquor concentrations, the steel pipe and the pipe fitting are lifted out in a head-to-tail manner when being lifted, residual floating oil stains and the like on the surface are washed in time by clear water, the surface quality is checked, and no black spots exist on the surface;

s2.2.2 soaking time of steel pipe and pipe fitting

Acid washing and oil removal: soaking in new acid solution for 8 hours, and lifting old acid solution for 12 hours;

whitening: soaking in new acid solution for 4 hours, and lifting old acid solution for 6 hours;

s2.2.3, the steel pipe and pipe fittings after acid cleaning and whitening must be five, namely no peracid, no acid deficiency, no oil, no lime and no residual acid, and the oil removal is realized without dripping water to form beads;

s2.2.4, washing the steel pipe until the inner wall is free of scale, dirt and residual acid, and the pressure of high-pressure water is more than 6 atmospheric pressures;

s2.3, plastering

S2.3.1 mixing mortar

Selecting high-quality quicklime, screening by a 50-mesh sieve, precipitating with water until the quicklime is dried to eighty percent, uniformly stirring with 3# industrial fat to form a colloidal state, and then adding water to dilute into a slurry state;

s2.3.2, plastering

S2.3.3 coating the inner wall of the tube with core diameter, drying, and coating the outer wall; the outer wall of the tube with the outer diameter is coated and then dried.

S2.3.4, when coating, the inner and outer surface coatings should be thin and uniform, not allowing to flow or block;

s2.4, drying

S2.4.1, the furnace numbers are clearly distinguished during air drying, the messy stack air drying is avoided, and the furnace numbers are layered according to different furnace numbers, with the high heads and the low tails, so as to facilitate the water flowing out.

Specifically, the pipe head treatment comprises pipe drawing and head beating and pipe drawing joints, wherein for a pierced billet with the outer diameter less than or equal to phi 65mm or a steel pipe in a product, the pipe drawing and head beating are carried out; for the pierced billet with the outer diameter larger than phi 65mm or the steel pipe in the product, a drawing head can be welded by adopting a sub-arc welding method.

Specifically, the pipe-drawing and heading operation comprises the following steps:

s3.1, preparation: when the head is beaten, the size of the head meets the process requirements, the length of the head is 150mm, and the shoulder of the head after beating is required to be smooth and have no edges and corners;

s3.2, selecting: the tail end of the pierced billet is headed, and the end with poor quality is headed when the product is produced;

s3.3, standard: the steel pipe with the core drawing diameter needs to be perforated in the shoulder transition area, and the perforation size is based on air permeability, and the smaller the perforation size is, the better the perforation size is;

s3.4, requiring: when heating, strictly controlling temperature, loading materials frequently, turning materials frequently, heating quickly, beating quickly and cooling quickly;

s3.5, temperature control: the heating temperature of the head beating is 1100 ℃, and the cooling mode is air cooling;

s3.6, heating requirement: the head is inserted into the heating hole and heated, the insertion depth is about 200mm, and the heating temperature is preferably red when the head is observed by naked eyes.

Specifically, the pipe joint pulling operation comprises the following steps:

s4.1, selecting a joint: selecting an old pipe head or a new pipe head which is suitable for the corresponding specification, and welding the old pipe head or the new pipe head to one end of a pierced billet or a product pipe;

s4.2, standard: the welded end should be cut flush, the edge is smooth and has circular arc, after welding, the welding seam should be lower than the external diameter of the tube, in order to prevent from contacting the drawing die while drawing, and require sufficient intensity, in order to avoid breaking;

and S4.3, cutting off the head every time after the drawing is finished, wherein the welding head can be repeatedly used.

Specifically, the cold rolling operation process is as follows:

s6.1, before production, oil filling and heat engine are carried out according to equipment operation rules, and the equipment is piled according to equipment point inspection requirements for point inspection;

s6.2, checking the steel type, the furnace number, the specification and the count of the incoming material according to the data on the production flow list, and recording the data on the production flow list;

s6.3, before the steel pipe is loaded on a rolling mill, the inner hole of the steel pipe needs to be filled with oil, when the oil is filled, one end of the steel pipe is higher and the other end of the steel pipe is lower, the oil is filled from the higher end and flows out from the lower end, and the steel pipe is turned over, so that the oil is applied to the periphery of the inner hole of the;

s6.4, when the first steel pipe is rolled, a steel pipe with the same specification (the same as the rolling specification) is used as a guide in the front clamp, the size tolerance must be measured and the surface quality needs to be checked when the hole pattern of the steel pipe is rolled out, and when the size tolerance does not meet the requirement, the distance between the rollers and the position of the top head need to be adjusted to enable the rollers to meet the requirement of the tolerance;

s6.5, when the rolling mill is started, slowly accelerating from a slow speed, and strictly prohibiting direct starting at a high speed;

s6.6, during rolling, the rolling speed and the feeding amount of a tube blank need to be mastered, the main motor is generally controlled at about 500 revolutions per minute, the frame reciprocates for about 80 times per minute and 10mm per time (the deformation is large, the feeding amount is small, the deformation is small, and the feeding amount is large according to the adjustment of the rolling deformation), the over speed is strictly forbidden, and the feeding amount is strictly forbidden to be increased;

s6.7, during rolling, paying attention to the surface quality of the rolled steel pipe at any time (special oil wiping workers are needed to be provided, and the surface quality is checked at the same time), and the existence of bamboo joint shapes, rolling burrs, rolling folds and lugs is not allowed, so that the steel pipe is immediately stopped, the reasons are found and solved, and if the defects of the hole pattern are found, people with rich experience and high technical level need to grind the steel pipe to enable the steel pipe to meet the quality requirement;

s6.8, when the hole patterns are repaired, adjusted, disassembled and assembled, the main power supply is cut off, the machine can be started, and the work is strictly forbidden;

and S6.9, finishing rolling, checking the surface quality and counting the counts, filling and writing a production flow list and a process control record, and well performing field civilized production work.

Specifically, the heat treatment of the pipe fitting adopts solid hot melting treatment, and the operation method of the solid hot melting treatment comprises the following steps:

s7.1, the inner surface and the outer surface of the steel pipe subjected to solution treatment are required to be clean without residual acid, residual oil, residual lime and dirt, otherwise, the steel pipe can be subjected to solution treatment after being deoiled and cleaned again;

s7.2, checking whether the gas burners are blocked one by one, checking whether pipeline valves are opened flexibly, whether a fan and a water pump work normally, and confirming whether control instruments such as a flow meter, a pressure meter and a thermometer display normally one by one;

s7.3, after the furnace bottom conveying pipeline is pulled by hands, testing the furnace bottom conveying pipeline for 3 minutes under an empty load, and checking whether the stepless speed regulation of the furnace bottom conveying roller way is normal or not;

and S7.4, firstly opening 2 burners to heat the furnace body, simultaneously starting a furnace bottom roller way, feeding the steel pipe for heating when the temperature of the furnace reaches above 800 ℃, increasing the burners according to the heating speed of the steel pipe, controlling the running speed of the steel pipe, and ensuring the solid solution temperature and time of the steel pipe.

Specifically, the straightening operation method comprises the following steps:

s8.1, before starting, checking whether the straightener is normal, adding a proper amount of lubricating oil, and starting the straightener empty for one minute under the condition that the equipment is good so as to observe the running condition;

s8.2, the bending degree of the incoming material pipe cannot be too large, otherwise, manual initial correction is applied, and the material is added and straightened under the condition that the equipment capacity requirement is met;

s8.3, during straightening, adjusting the inclination angle of the straightening roller, the roller distance of the straightening roller and the position of the second pair of rollers, and simultaneously, correctly installing and adjusting an inlet guide plate to ensure the straightening quality;

s8.4, during straightening, spiral dents, straightening squares and straightening feathers are not allowed to be generated, and the dimension of the finished product pipe is not allowed to be corrected to be unqualified;

s8.5, properly widening the cold-rolled pipe according to the bending degree of the straightened pipe, wherein the core diameter pipe is not more than 15 mm/m;

s8.6, keeping the straightening roller clean, finding the conditions of fluffing, damage, iron adhesion and the like of the roller surface, and timely polishing the roller surface by using sand paper or a grinding wheel, and if the straightening quality is influenced by serious defects, timely replacing the roller;

and S8.7, carrying out the large-caliber steel pipe on a three-point type simple straight straightening machine.

Specifically, the operation method of cutting the pipe is as follows:

s9.1, checking the cutting equipment and keeping a good running state;

s9.2, cutting the head, the tail or the length into a defined fixed length according to the standard requirement;

s9.3, when the head of the product is cut, the head of the product can be left with an old pipe head of 120mm, and when the head of the large-caliber pipe is cut, the head of the large-caliber pipe must be completely cut, cut evenly and cut flatly, so that the pipe head can be welded conveniently;

s9.4, when the end of the finished product is cut and the tail is cut, the pipe head is completely cut, the part with uneven wall thickness at the tail is completely cut, and metal is saved;

s9.5, removing burrs at two ends of the cut pipe by using a file or a grinding wheel, and blowing off carborundum in the pipe by using compressed air;

s9.6, after the products are cut, sending the cut products to a headed steel pipe, wherein the headed end is arranged at one end and is arranged in order; sending to the acid-washed pipe, and arranging one end of the pipe;

s9.7, placing the cut pipe head, the cut pipe tail and the waste products in a waste pile according to steel types to prevent steel mixing.

Example 3

Referring to fig. 1-2, the present invention provides the following technical solutions: the cold rolling production process of the stainless steel seamless pipe comprises the following steps which are sequentially and continuously carried out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery.

Specifically, the pickling operation requires the following:

s2.1, preparing acid solution

Distribution of pickling baths: from front to back, a No. 1 common acid pool, a No. 2 common acid pool and a No. 3 whitening pool are respectively arranged;

s2.1.1, acid liquor proportioning ratio and pickling bath temperature: hydrofluoric acid: nitric acid = 2: 3. 70% of aqueous solution, 30% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: at 40 ℃, a whitening pool: hydrofluoric acid: nitric acid = 1: 2. 50% of aqueous solution, 50% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 30 ℃;

s2.1.2, preparing the acid solution once every 3 days in the common acid tank, and preparing the acid solution once every 13 days in the whitening tank;

s2.1.3, when the pH value of the acid solution is more than 3 or the oxide skin and dirt on the surface of the steel pipe or the pipe fitting can not be washed cleanly, preparing a new solution;

s2.1.4, thoroughly cleaning the acid mud in the acid pool every month;

s2.2, acid washing

S2.2.1, before the steel pipe and the pipe fitting are put into a cylinder, the solution is stirred uniformly, then the steel pipe and the pipe fitting are obliquely put into the cylinder to be soaked in a head-to-tail manner, the soaking time of the steel pipe and the pipe fitting is different according to different acid liquor concentrations, the steel pipe and the pipe fitting are lifted out in a head-to-tail manner when being lifted, residual floating oil stains and the like on the surface are washed in time by clear water, the surface quality is checked, and no black spots exist on the surface;

s2.2.2 soaking time of steel pipe and pipe fitting

Acid washing and oil removal: soaking in new acid solution for 7 hours, and lifting the old acid solution for 10 hours;

whitening: soaking in new acid solution for 4 hours, and lifting old acid solution for 5 hours;

s2.2.3, the steel pipe and pipe fittings after acid cleaning and whitening must be five, namely no peracid, no acid deficiency, no oil, no lime and no residual acid, and the oil removal is realized without dripping water to form beads;

s2.2.4, washing the steel pipe until the inner wall is free of scale, dirt and residual acid, and the pressure of high-pressure water is more than 6 atmospheric pressures;

s2.3, plastering

S2.3.1 mixing mortar

Selecting high-quality quicklime, screening by a 45-mesh sieve, precipitating with water, drying to eighty percent, mixing with 3# industrial fat uniformly to form a colloidal state, and then adding water to dilute to a slurry state;

s2.3.2, plastering

S2.3.3 coating the inner wall of the tube with core diameter, drying, and coating the outer wall; the outer wall of the tube with the outer diameter is coated and then dried.

S2.3.4, when coating, the inner and outer surface coatings should be thin and uniform, not allowing to flow or block;

s2.4, drying

S2.4.1, the furnace numbers are clearly distinguished during air drying, the messy stack air drying is avoided, and the furnace numbers are layered according to different furnace numbers, with the high heads and the low tails, so as to facilitate the water flowing out.

Specifically, the pipe head treatment comprises pipe drawing and head beating and pipe drawing joints, wherein for a pierced billet with the outer diameter less than or equal to phi 65mm or a steel pipe in a product, the pipe drawing and head beating are carried out; for the pierced billet with the outer diameter larger than phi 65mm or the steel pipe in the product, a drawing head can be welded by adopting a sub-arc welding method.

Specifically, the pipe-drawing and heading operation comprises the following steps:

s3.1, preparation: when the head is beaten, the size of the head meets the process requirements, the length of the head is 130mm, and the shoulder of the head after beating is required to be smooth and have no edges and corners;

s3.2, selecting: the tail end of the pierced billet is headed, and the end with poor quality is headed when the product is produced;

s3.3, standard: the steel pipe with the core drawing diameter needs to be perforated in the shoulder transition area, and the perforation size is based on air permeability, and the smaller the perforation size is, the better the perforation size is;

s3.4, requiring: when heating, strictly controlling temperature, loading materials frequently, turning materials frequently, heating quickly, beating quickly and cooling quickly;

s3.5, temperature control: the heating temperature of the beating head is 1080 ℃, and the cooling mode is air cooling;

s3.6, heating requirement: the head is inserted into the heating hole and heated, the insertion depth is about 200mm, and the heating temperature is preferably red when the head is observed by naked eyes.

Specifically, the pipe joint pulling operation comprises the following steps:

s4.1, selecting a joint: selecting an old pipe head or a new pipe head which is suitable for the corresponding specification, and welding the old pipe head or the new pipe head to one end of a pierced billet or a product pipe;

s4.2, standard: the welded end should be cut flush, the edge is smooth and has circular arc, after welding, the welding seam should be lower than the external diameter of the tube, in order to prevent from contacting the drawing die while drawing, and require sufficient intensity, in order to avoid breaking;

and S4.3, cutting off the head every time after the drawing is finished, wherein the welding head can be repeatedly used.

Specifically, the cold rolling operation process is as follows:

s6.1, before production, oil filling and heat engine are carried out according to equipment operation rules, and the equipment is piled according to equipment point inspection requirements for point inspection;

s6.2, checking the steel type, the furnace number, the specification and the count of the incoming material according to the data on the production flow list, and recording the data on the production flow list;

s6.3, before the steel pipe is loaded on a rolling mill, the inner hole of the steel pipe needs to be filled with oil, when the oil is filled, one end of the steel pipe is higher and the other end of the steel pipe is lower, the oil is filled from the higher end and flows out from the lower end, and the steel pipe is turned over, so that the oil is applied to the periphery of the inner hole of the;

s6.4, when the first steel pipe is rolled, a steel pipe with the same specification (the same as the rolling specification) is used as a guide in the front clamp, the size tolerance must be measured and the surface quality needs to be checked when the hole pattern of the steel pipe is rolled out, and when the size tolerance does not meet the requirement, the distance between the rollers and the position of the top head need to be adjusted to enable the rollers to meet the requirement of the tolerance;

s6.5, when the rolling mill is started, slowly accelerating from a slow speed, and strictly prohibiting direct starting at a high speed;

s6.6, during rolling, the rolling speed and the feeding amount of a tube blank need to be mastered, the main motor is generally controlled at about 500 revolutions per minute, the frame reciprocates for about 75 times per minute and 8mm per time (the deformation is large, the feeding amount is small, the deformation is small, and the feeding amount is large) and the over speed is strictly forbidden and the feeding amount is strictly forbidden to be increased;

s6.7, during rolling, paying attention to the surface quality of the rolled steel pipe at any time, and not allowing the existence of bamboo joints, rolled burrs, rolled folds and lugs, finding the problems to stop immediately, finding out reasons and solving the problems, wherein if the hole pattern is found to be defective, personnel with rich experience and high technical level must repair the steel pipe to ensure that the steel pipe meets the quality requirement;

s6.8, when the hole patterns are repaired, adjusted, disassembled and assembled, the main power supply is cut off, the machine can be started, and the work is strictly forbidden;

and S6.9, finishing rolling, checking the surface quality and counting the counts, filling and writing a production flow list and a process control record, and well performing field civilized production work.

Specifically, the heat treatment of the pipe fitting adopts solid hot melting treatment, and the operation method of the solid hot melting treatment comprises the following steps:

s7.1, the inner surface and the outer surface of the steel pipe subjected to solution treatment are required to be clean without residual acid, residual oil, residual lime and dirt, otherwise, the steel pipe can be subjected to solution treatment after being deoiled and cleaned again;

s7.2, checking whether the gas burners are blocked one by one, checking whether pipeline valves are opened flexibly, whether a fan and a water pump work normally, and confirming whether control instruments such as a flow meter, a pressure meter and a thermometer display normally one by one;

s7.3, after the furnace bottom conveying pipeline is pulled by hands, testing the furnace bottom conveying pipeline for 3 minutes under an empty load, and checking whether the stepless speed regulation of the furnace bottom conveying roller way is normal or not;

and S7.4, firstly opening 2 burners to heat the furnace body, simultaneously starting a furnace bottom roller way, feeding the steel pipe for heating when the temperature of the furnace reaches above 800 ℃, increasing the burners according to the heating speed of the steel pipe, controlling the running speed of the steel pipe, and ensuring the solid solution temperature and time of the steel pipe.

Specifically, the straightening operation method comprises the following steps:

s8.1, before starting, checking whether the straightener is normal, adding a proper amount of lubricating oil, and starting the straightener empty for one minute under the condition that the equipment is good so as to observe the running condition;

s8.2, the bending degree of the incoming material pipe cannot be too large, otherwise, manual initial correction is applied, and the material is added and straightened under the condition that the equipment capacity requirement is met;

s8.3, during straightening, adjusting the inclination angle of the straightening roller, the roller distance of the straightening roller and the position of the second pair of rollers, and simultaneously, correctly installing and adjusting an inlet guide plate to ensure the straightening quality;

s8.4, during straightening, spiral dents, straightening squares and straightening feathers are not allowed to be generated, and the dimension of the finished product pipe is not allowed to be corrected to be unqualified;

s8.5, properly widening the cold-rolled pipe according to the bending degree of the straightened pipe, wherein the core diameter pipe is not more than 15 mm/m;

s8.6, keeping the straightening roller clean, finding the conditions of fluffing, damage, iron adhesion and the like of the roller surface, and timely polishing the roller surface by using sand paper or a grinding wheel, and if the straightening quality is influenced by serious defects, timely replacing the roller;

and S8.7, carrying out the large-caliber steel pipe on a three-point type simple straight straightening machine.

Specifically, the operation method of cutting the pipe is as follows:

s9.1, checking the cutting equipment and keeping a good running state;

s9.2, cutting the head, the tail or the length into a defined fixed length according to the standard requirement;

s9.3, when the head of the product is cut, the head of the product can be left with an old pipe head of 100mm, and when the head of the large-diameter pipe is cut, the head of the large-diameter pipe must be completely cut, neat and flat, so that the pipe head can be welded conveniently;

s9.4, when the end of the finished product is cut and the tail is cut, the pipe head is completely cut, the part with uneven wall thickness at the tail is completely cut, and metal is saved;

s9.5, removing burrs at two ends of the cut pipe by using a file or a grinding wheel, and blowing off carborundum in the pipe by using compressed air;

s9.6, after the products are cut, sending the cut products to a headed steel pipe, wherein the headed end is arranged at one end and is arranged in order; sending to the acid-washed pipe, and arranging one end of the pipe;

s9.7, placing the cut pipe head, the cut pipe tail and the waste products in a waste pile according to steel types to prevent steel mixing.

In step S2.4, the air-drying time requirements of different steel pipes and pipe fittings are shown in fig. 2 in order to prevent scorching.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation. The phrase "comprising a defined element does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. The stainless steel seamless tube cold rolling production line and the production process are characterized in that: comprises the following steps which are sequentially and continuously carried out: raw material purchase → inspection → acid washing → coping → cutting head → cold rolling → inspection → deoiling → heat treatment → acid washing → coping → straightening → inspection → cutting head → passivation → marking → packaging → finished product warehousing → delivery.

2. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the operating requirements for pickling are as follows:

s2.1, preparing acid solution

Distribution of pickling baths: from front to back, a No. 1 common acid pool, a No. 2 common acid pool and a No. 3 whitening pool are respectively arranged;

s2.1.1, acid liquor proportioning ratio and pickling bath temperature: hydrofluoric acid: nitric acid = 2: 3. 70% of aqueous solution, 30% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 25-50 ℃ and a whitening pool: hydrofluoric acid: nitric acid = 1: 2. 50% of aqueous solution, 50% of total acid ratio of hydrofluoric acid and nitric acid, and the temperature range of the pickling bath is as follows: 20-40 ℃;

s2.1.2, preparing the acid solution once every 3 days in the common acid tank, and preparing the acid solution once every 10-15 days in the albino tank;

s2.1.3, when the pH value of the acid solution is more than 3 or the oxide skin and dirt on the surface of the steel pipe or the pipe fitting can not be washed cleanly, preparing a new solution;

s2.1.4, thoroughly cleaning the acid mud in the acid pool every month;

s2.2, acid washing

S2.2.1, before the steel pipe and the pipe fitting are put into a cylinder, the solution is stirred uniformly, then the steel pipe and the pipe fitting are obliquely put into the cylinder to be soaked in a head-to-tail manner, the soaking time of the steel pipe and the pipe fitting is different according to different acid liquor concentrations, the steel pipe and the pipe fitting are lifted out in a head-to-tail manner when being lifted, residual floating oil stains and the like on the surface are washed in time by clear water, the surface quality is checked, and no black spots exist on the surface;

s2.2.2 soaking time of steel pipe and pipe fitting

Acid washing and oil removal: soaking in the new acid solution for 6-8 hours, and lifting the old acid solution for 8-12 hours;

whitening: soaking in new acid liquor for 3-4 hours, and lifting old acid liquor for 4-6 hours;

s2.2.3, the steel pipe and pipe fittings after acid cleaning and whitening must be five, namely no peracid, no acid deficiency, no oil, no lime and no residual acid, and the oil removal is realized without dripping water to form beads;

s2.2.4, washing the steel pipe until the inner wall is free of scale, dirt and residual acid, and the pressure of high-pressure water is more than 6 atmospheric pressures;

s2.3, plastering

S2.3.1 mixing mortar

Selecting high-quality quicklime, screening by using a 40-50-mesh sieve, precipitating by using water, drying to eighty percent, uniformly stirring with 3# industrial fat to form a colloidal state, and then adding water to dilute into a slurry state;

s2.3.2, plastering

S2.3.3 coating the inner wall of the tube with core diameter, drying, and coating the outer wall; the outer wall of the tube with the outer diameter is coated and then dried.

S2.3.4, when coating, the inner and outer surface coatings should be thin and uniform, not allowing to flow or block;

s2.4, drying

S2.4.1, the furnace numbers are clearly distinguished during air drying, the messy stack air drying is avoided, and the furnace numbers are layered according to different furnace numbers, with the high heads and the low tails, so as to facilitate the water flowing out.

3. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the pipe head processing comprises a pipe drawing head and a pipe drawing connector.

4. The cold rolling production process of a stainless steel seamless tube according to claim 3, characterized in that: the pipe drawing and heading operation comprises the following steps:

s3.1, preparation: when the head is punched, the size of the head meets the technological requirements, the length of the head is 120-150 mm, and the shoulder of the head after punching is required to be smooth and have no edges and corners;

s3.2, selecting: the tail end of the pierced billet is headed, and the end with poor quality is headed when the product is produced;

s3.3, standard: the steel pipe with the core drawing diameter needs to be perforated in the shoulder transition area, and the perforation size is based on air permeability, and the smaller the perforation size is, the better the perforation size is;

s3.4, requiring: when heating, strictly controlling temperature, loading materials frequently, turning materials frequently, heating quickly, beating quickly and cooling quickly;

s3.5, temperature control: the heating temperature of the head is 1050-1100 ℃, and the cooling mode is air cooling;

s3.6, heating requirement: the head is inserted into the heating hole and heated, the insertion depth is about 200mm, and the heating temperature is preferably red when the head is observed by naked eyes.

5. The cold rolling production process of a stainless steel seamless tube according to claim 3, characterized in that: the pipe joint pulling operation comprises the following steps:

s4.1, selecting a joint: selecting an old pipe head or a new pipe head which is suitable for the corresponding specification, and welding the old pipe head or the new pipe head to one end of a pierced billet or a product pipe;

s4.2, standard: the welded end should be cut flush, the edge is smooth and has circular arc, after welding, the welding seam should be lower than the external diameter of the tube, in order to prevent from contacting the drawing die while drawing, and require sufficient intensity, in order to avoid breaking;

and S4.3, cutting off the head every time after the drawing is finished, wherein the welding head can be repeatedly used.

6. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the cold rolling operation process is as follows:

s6.1, before production, oil filling and heat engine are carried out according to equipment operation rules, and the equipment is piled according to equipment point inspection requirements for point inspection;

s6.2, checking the steel type, the furnace number, the specification and the count of the incoming material according to the data on the production flow list, and recording the data on the production flow list;

s6.3, before the steel pipe is fed into a rolling mill, the inner hole of the steel pipe needs to be filled with oil, when the oil is filled, one end of the steel pipe is higher, the other end of the steel pipe is lower, the oil is filled from the higher end, the oil flows out from the lower end, and the steel pipe is turned over, so that the oil is applied to the periphery of the inner hole;

s6.4, when the first steel pipe is rolled, one steel pipe with the same specification is used as a guide in the front clamp, the size tolerance must be measured and the surface quality must be checked when the hole pattern of the rolled steel pipe is rolled out, and when the size tolerance does not meet the requirement, the distance between the rollers and the position of the top head need to be adjusted to enable the rollers to meet the requirement of the tolerance;

s6.5, when the rolling mill is started, slowly accelerating from a slow speed, and strictly prohibiting direct starting at a high speed;

s6.6, during rolling, the rolling speed and the feeding amount of the tube blank need to be mastered, the main motor is generally controlled at about 500 revolutions per minute, the frame reciprocates for about 70-80 times per minute and 6-10mm per time, overspeed is strictly prohibited, and the feeding amount is strictly prohibited from increasing;

s6.7, during rolling, paying attention to the surface quality of the rolled steel pipe at any time, and not allowing the existence of bamboo joints, rolled burrs, rolled folds and lugs, finding the problems to stop immediately, finding out reasons and solving the problems, wherein if the hole pattern is found to be defective, personnel with rich experience and high technical level must repair the steel pipe to ensure that the steel pipe meets the quality requirement;

s6.8, when the hole patterns are repaired, adjusted, disassembled and assembled, the main power supply is cut off, the machine can be started, and the work is strictly forbidden;

and S6.9, finishing rolling, checking the surface quality and counting the counts, filling and writing a production flow list and a process control record, and well performing field civilized production work.

7. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the heat treatment of the pipe fitting adopts solid hot melting treatment, and the operation method of the solid hot melting treatment comprises the following steps:

s7.1, the inner surface and the outer surface of the steel pipe subjected to solution treatment are required to be clean without residual acid, residual oil, residual lime and dirt, otherwise, the steel pipe can be subjected to solution treatment after being deoiled and cleaned again;

s7.2, checking whether the gas burners are blocked one by one, checking whether pipeline valves are opened flexibly, whether a fan and a water pump work normally, and confirming whether control instruments such as a flow meter, a pressure meter and a thermometer display normally one by one;

s7.3, after the furnace bottom conveying pipeline is pulled by hands, testing the furnace bottom conveying pipeline for 3 minutes under an empty load, and checking whether the stepless speed regulation of the furnace bottom conveying roller way is normal or not;

and S7.4, firstly opening 1-2 burners to heat the furnace body, simultaneously starting a furnace bottom roller way, feeding the steel pipe for heating when the temperature of the furnace reaches above 800 ℃, increasing the burners according to the heating speed of the steel pipe, controlling the running speed of the steel pipe, and ensuring the solid solution temperature and time of the steel pipe.

8. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the straightening operation method comprises the following steps:

s8.1, before starting, checking whether the straightener is normal, adding a proper amount of lubricating oil, and starting the straightener empty for one minute under the condition that the equipment is good so as to observe the running condition;

s8.2, the bending degree of the incoming material pipe cannot be too large, otherwise, manual initial correction is applied, and the material is added and straightened under the condition that the equipment capacity requirement is met;

s8.3, during straightening, adjusting the inclination angle of the straightening roller, the roller distance of the straightening roller and the position of the second pair of rollers, and simultaneously, correctly installing and adjusting an inlet guide plate to ensure the straightening quality;

s8.4, during straightening, spiral dents, straightening squares and straightening feathers are not allowed to be generated, and the dimension of the finished product pipe is not allowed to be corrected to be unqualified;

s8.5, properly widening the cold-rolled pipe according to the bending degree of the straightened pipe, wherein the core diameter pipe is not more than 15 mm/m;

s8.6, keeping the straightening roller clean, finding the conditions of fluffing, damage, iron adhesion and the like of the roller surface, and timely polishing the roller surface by using sand paper or a grinding wheel, and if the straightening quality is influenced by serious defects, timely replacing the roller;

and S8.7, carrying out the large-caliber steel pipe on a three-point type simple straight straightening machine.

9. The cold rolling production process of a stainless steel seamless tube according to claim 1, characterized in that: the operation method of cutting the tube is as follows:

s9.1, checking the cutting equipment and keeping a good running state;

s9.2, cutting the head, the tail or the length into a defined fixed length according to the standard requirement;

s9.3, when the head of the product is cut, the head of the product can be left with an old pipe head of 80-120mm, and when the head of the large-caliber pipe is cut, the head of the large-caliber pipe must be completely cut, neat and flat, so that the pipe head can be welded conveniently;

s9.4, when the end of the finished product is cut and the tail is cut, the pipe head is completely cut, the part with uneven wall thickness at the tail is completely cut, and metal is saved;

s9.5, removing burrs at two ends of the cut pipe by using a file or a grinding wheel, and blowing off carborundum in the pipe by using compressed air;

s9.6, after the products are cut, sending the cut products to a headed steel pipe, wherein the headed end is arranged at one end and is arranged in order; sending to the acid-washed pipe, and arranging one end of the pipe;

s9.7, placing the cut pipe head, the cut pipe tail and the waste products in a waste pile according to steel types to prevent steel mixing.

10. A stainless steel seamless tube cold rolling line for the stainless steel seamless tube cold rolling production process according to any one of claims 1 to 9, characterized in that: the device comprises the following devices which are sequentially arranged along the product conveying direction:

acid pickling equipment: a pickling tank is adopted for pickling pierced billets;

drying equipment: the method adopts a drying furnace for drying the pierced billet;

the on-line heading equipment comprises: the method adopts a heading machine for heading the pierced billet;

online piecing equipment: the method adopts a welding machine for jointing pierced billets;

cold rolling equipment: the method adopts a cold rolling mill for cold rolling the pierced billet;

and (3) heat treatment equipment: the method adopts a solid solution machine for carrying out heat treatment on the pierced billet;

grinding equipment: the method adopts a grinding machine for grinding the pierced billet;

straightening equipment: the method adopts a straightening machine for straightening the pierced billet;

cutting equipment: the cutting machine is used for cutting the product pipe fitting;

polishing equipment: the polishing machine is used for polishing the product pipe fitting;

a marking device: the marking machine is used for marking and classifying the product pipe fittings;

packaging equipment: the packaging machine is used for packaging the product pipe fitting;

conveying equipment: which employs a conveyor belt for conveying the product tubes.

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