CN104759835A - Manufacturing method of hot-rolled high-precision petroleum pipe - Google Patents

Abstract

The invention relates to a manufacturing method of a hot-rolled high-precision petroleum pipe. The manufacturing method comprises the following steps: heating: a pipe blank is heated in an annular furnace; perforation: the heated pipe blank is perforated by a perforator; annealing: the pipe blank is annealed; spraying of boron sand: oxide scales are removed; hot rolling: the annealed pipe blank is led into a pipe rolling machine for hot rolling; sizing: the rolled pipe formed by continuous rolling is sized by a sizing machine; stress relief annealing: the rolled pipe is led into a heating furnace for heating so that the annealed pipe blank is obtained; acid washing: rust scales on the surface are removed; parkerizing: a chemical coating film of zinc phosphate is formed on the surface; saponification: such lubricating coating films as a metallic soap are formed; cold rolling: the pipe blank to be cold rolled is cold rolled to obtain a cold-rolled pipe; heat treatment: residual stress is reduced; pre-straightening: the residual stress is reduced; quenching in an induction furnace; tempering in a chamber furnace; honing; hot straightening; and obtaining of the high-precision steel pipe. The method is used for manufacturing the high-precision steel pipe with high yield strength and size precision.

Description

A kind of manufacture method of hot rolling high precision petroleum pipe

Technical field

The invention belongs to steel pipe preparing technical field, be specifically related to a kind of manufacture method of hot rolling high precision petroleum pipe.

Background technology

As the cold process of the steel for mechanical structure pipes such as carbon steel, alloy steel or stainless steel, there are known the drawing processing method of being undertaken by drawbench and the rolling processing method of being undertaken by Pierre's form milling train.Wherein, the drawing processing method of being undertaken by drawbench, compared with the rolling processing method of carrying out with machine of being pricked by Pierre's form, cold working steel pipe can be manufactured expeditiously, this seamless steel pipe is used for oil hydraulic cylinder, pneumatic cylinder uses, and at present, most Hi-grade steel its yield strength, dimensional discrepancy etc. of domestic current prescribed by standard all cannot meet the instructions for use of actual oil hydraulic cylinder, pneumatic cylinder, make the oil hydraulic cylinder of China, pneumatic cylinder seamless steel pipe can only dependence on import, constrain the development of China's cold tube rolling.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of manufacture method of hot rolling high precision petroleum pipe is provided, the cold rolling high-accuracy weldless steel tube that the method obtains, yield strength is high, tensile strength is high, precision size, smooth surface, its store oil excellent performance, makes running more smooth and easy, without stall condition, expanded service life, is applicable to the various laborsaving automated machine engineerings such as oil hydraulic cylinder, pneumatic cylinder, fork truck, crane, stacker, building machinery, punch press.

According to technical scheme provided by the invention, a kind of manufacture method of hot rolling high precision petroleum pipe comprises the steps:

(1), heating: 27SiMn pipe is heated to 1200 ~ 1280 DEG C in annular furnace, and the heat time is 3 ~ 4 hours, thus ensures that heating of pipe blank is even;

(2), bore a hole: heat pipe base perforated machine is bored a hole, the temperature of the hollow billet formed after perforation controls at 1100 ~ 1150 DEG C, and order control punch eccentricity and control pipe surface quality;

(3), annealing: introduced in continuous annealing furnace by pipe and anneal, and order control annealing temperature is 500 ~ 600 DEG C, annealing time is 50 ~ 60min, obtains the annealing pipe that annealing hardness (HV) is 210 ~ 217;

(4), borax is sprayed: spray borax device blows to the descaling of hollow billet endoporus nitrogen and borax through spiral nozzle and fill nitrogen in hollow billet, its main function is removed by the residual oxidization skin in hollow billet, form a skim at the inner surface of hollow billet simultaneously, prevent hollow billet to be further oxidized;

(5), hot rolling: pipe of annealing introduces pipe mill hot rolling, and hot-rolled temperature is 1240 ~ 1250 DEG C, obtains rolled pipe;

(6), sizing: the rolled pipe formed after tandem rolling is again through sizing mill sizing, and form steel pipe, finishing temperature control during sizing is at 800 ~ 850 DEG C;

(7), stress relief annealing: rolled pipe introduced heating in heating furnace and be incubated, come out of the stove with after stove cooling, obtain pipe of annealing, object is the intensity guaranteeing steel pipe, when annealing temperature is too high, processing strain recovers, can not obtain the effect of work hardening, annealing temperature is 550 ~ 650 DEG C, can obtain the effect of work hardening, in order to remove the strength variance of cold tube rolling, in the stove of cold tube rolling, the retention time is 10 ~ 20 minutes;

(8), pickling processes: annealing pipe is carried out pickling, removes the scale on surface, concentration of hydrochloric acid: 7 ~ 19%, pickling time: 35 ~ 60 minutes, then neutralization pond rolling, rolling number of times: 2 ~ 3 times, neutralizer pH value: 9 ~ 10, then through clear water reserviors rolling, rolling number of times: 2 ~ 3 times;

(9), phosphorating treatment: the chemistry forming trbasic zinc phosphate on the surface of pipe generates overlay film, trbasic zinc phosphate concentration: 20 ~ 30%, Phosphating Solution temperature: 68 ~ 75 DEG C, phosphating time: 10 ~ 20 minutes, Phosphating Solution free acidity: 4 ~ 7, General Acidity in Phosphating Solution: 45 ~ 75;

(10), saponification process: form the lubricating film coateds such as metallic soap on overlay film, saponification temperature: 55 ~ 75 DEG C, saponification time: 8 ~ 15 minutes, saponification liquor pH value: 8 ~ 9;

(11), cold rolling: will treat that cold rolling pipe carries out cold rolling processing, and obtain cold rolled tube, the reciprocal time of the headstock of pipe mill is 20 ~ 30 times/min, and the length of at every turn sending to of pipe is 6 ~ 8mm/ time, obtains rolled pipe;

(12), heat treatment: the Technology for Heating Processing adopting tempering again after quenching, hardening heat is 600 ~ 800 DEG C, and hardening media is water, and temperature, at 400 ~ 550 DEG C, reduces the residual stress of drawn tube;

(13), pre-straightening process: straightening temperature 500 ~ 650 DEG C, to reduce residual stress;

(14), induction furnace Quenching Treatment: induction furnace hardening heat is 750 ~ 850 DEG C, and hardening media is water, reduces the residual stress of drawn tube;

(15), temper in batch-type furnace: the temperature of tempering air cooling is 300 ~ 400 DEG C, to reduce residual stress;

(16), honing: select vertical honing machine, workpiece turns round, and the form processing that honing head is reciprocating, reaches cylindricity: 0.01 ~ 0.02mm, Aperture deviation: 0.01 ~ 0.02mm, roughness: the high standard precision of Ra0.25 ~ 0.35;

(17), thermal straightening process: be incubated 45 ~ 60 minutes in low-temp temper furnace, carry out thermal straightening process again, thermal straightening temperature 450 ~ 550 DEG C, obtain yield strength (MPa): 896, tensile strength (MPa): 918, hardness (HV): 250, wall thickness tolerance: 8%, external diameter out-of-roundness: 0.3%, eccentricity: 6%, the cold rolling high-accuracy weldless steel tube of linearity: 0.30mm/m.

Beneficial effect of the present invention is as follows: the cold rolling high-accuracy weldless steel tube utilizing the inventive method to produce, good combination property, low-temperature impact toughness is good, there is higher rotational deformation drag and wearability, its yield strength reaches 896MPa, tensile strength reaches 918MPa, cold rolling by adopting, heat treatment and straightening process, make the mechanical performance of cold rolling high-accuracy weldless steel tube body, rotational deformation drag, low-temperature impact work and anti-wear performance up to standard, by controlling the physical dimension of body, residual stress, form variations and chemical analysis, the mechanical performance of body can be ensured, high wearability, low temperature resistant and high rotational deformation drag, precision size, smooth surface, its store oil excellent performance, make running more smooth and easy, without stall condition, expanded service life, be applicable to oil hydraulic cylinder, pneumatic cylinder, fork truck, crane, stacker, building machinery, the various laborsaving automated machine engineering such as punch press.

Detailed description of the invention:

Below in conjunction with specific embodiment, the invention will be further described.

Embodiment one:

To prepare diameter for 159.3mm and the hole wall wall thickness 27SiMn steel pipe that is 6.3mm, comprise the following steps:

(1), heating: 27SiMn pipe is heated to 1200 DEG C in annular furnace, and the heat time is 3 hours, thus ensures that heating of pipe blank is even;

(2), bore a hole: heat pipe base perforated machine is bored a hole, the temperature of the hollow billet formed after perforation controls at 1100 DEG C, and order control punch eccentricity is 4%, visualize is carried out to pipe, use remove pipe surface burr, stick up skin, if pipe surface occurs or there is pit that significantly namely naked eyes are obvious, runs over and injure and crackle, then should reject, avoid flowing into subsequent processing, to control pipe surface quality;

(3), annealing: introduced in continuous annealing furnace by pipe and anneal, and order control annealing temperature is 500 DEG C, annealing time is 50min, obtains the annealing pipe that annealing hardness (HV) is 210;

(4), borax is sprayed: spray borax device blows to the descaling of hollow billet endoporus nitrogen and borax through spiral nozzle and fill nitrogen in hollow billet, its main function is removed by the residual oxidization skin in hollow billet, form a skim at the inner surface of hollow billet simultaneously, prevent hollow billet to be further oxidized;

(5), hot rolling: pipe of annealing introduces pipe mill hot rolling, and hot-rolled temperature is 1240 DEG C, obtains rolled pipe;

(6), sizing: the rolled pipe formed after tandem rolling is again through sizing mill sizing, and form steel pipe, finishing temperature control during sizing is at 800 DEG C;

(7), stress relief annealing: rolled pipe introduced heating in heating furnace and be incubated, come out of the stove with after stove cooling, obtain pipe of annealing, object is the intensity guaranteeing steel pipe, when annealing temperature is too high, processing strain recovers, can not obtain the effect of work hardening, annealing temperature is 550 DEG C, can obtain the effect of work hardening, in order to remove the strength variance of cold tube rolling, in the stove of cold tube rolling, the retention time is 10 minutes;

(8), pickling processes: annealing pipe is carried out pickling, removes the scale on surface, concentration of hydrochloric acid: 7%, pickling time: 35 minutes, then neutralization pond rolls, rolling number of times: 2 times, neutralizer pH value: 9, then roll through clear water reserviors, rolling number of times: 2 times;

(9), phosphorating treatment: the chemistry forming trbasic zinc phosphate on the surface of pipe generates overlay film, trbasic zinc phosphate concentration: 20%, Phosphating Solution temperature: 68 DEG C, phosphating time: 10 minutes, Phosphating Solution free acidity: 4, General Acidity in Phosphating Solution: 45;

(10), saponification process: form the lubricating film coateds such as metallic soap on overlay film, saponification temperature: 55 DEG C, saponification time: 8 minutes, saponification liquor pH value: 8;

(11), cold rolling: will treat that cold rolling pipe carries out cold rolling processing, and obtain cold rolled tube, the reciprocal time of the headstock of pipe mill is 20 times/min, and the length of at every turn sending to of pipe is 6mm/ time, obtains rolled pipe;

(12), heat treatment: the Technology for Heating Processing adopting tempering again after quenching, hardening heat is 600 DEG C, and hardening media is water, and temperature, at 400 DEG C, reduces the residual stress of drawn tube;

(13), pre-straightening process: straightening temperature 500 DEG C, to reduce residual stress;

(14), induction furnace Quenching Treatment: induction furnace hardening heat is 750 DEG C, and hardening media is water, reduces the residual stress of drawn tube;

(15), temper in batch-type furnace: the temperature of tempering air cooling is 300 DEG C, to reduce residual stress;

(16), honing: select vertical honing machine, workpiece turns round, and the form processing that honing head is reciprocating, reaches cylindricity: 0.01mm, Aperture deviation: 0.01mm, roughness: the high standard precision of Ra0.25;

(17), thermal straightening process: be incubated 45 minutes in low-temp temper furnace, carry out thermal straightening process again, thermal straightening temperature 450 DEG C, obtain yield strength (MPa): 896, tensile strength (MPa): 918, hardness (HV): 250, wall thickness tolerance: 8%, external diameter out-of-roundness: 0.3%, eccentricity: 6%, the cold rolling high-accuracy weldless steel tube of linearity: 0.30mm/m.

After testing, institute's inspection project meets GB/T3639-2009 standard to the product that the present embodiment obtains, and product is qualified, meets the requirement of user to yield strength, tensile strength, hardness, precision.

The contrast in technical performance of a kind of cold rolling high-accuracy weldless steel tube and conventional steel pipe

Embodiment two:

To prepare diameter for 139.9mm and the hole wall wall thickness 27SiMn steel pipe that is 7.9mm, comprise the following steps:

(1), heating: 27SiMn pipe is heated to 1280 DEG C in annular furnace, and the heat time is 4 hours, thus ensures that heating of pipe blank is even;

(2), bore a hole: heat pipe base perforated machine is bored a hole, the temperature of the hollow billet formed after perforation controls at 1150 DEG C, and order control punch eccentricity is 4%, visualize is carried out to pipe, use remove pipe surface burr, stick up skin, if pipe surface occurs or there is pit that significantly namely naked eyes are obvious, runs over and injure and crackle, then should reject, avoid flowing into subsequent processing, to control pipe surface quality;

(3), annealing: introduced in continuous annealing furnace by pipe and anneal, and order control annealing temperature is 600 DEG C, annealing time is 60min, obtains the annealing pipe that annealing hardness (HV) is 217;

(4), borax is sprayed: spray borax device blows to the descaling of hollow billet endoporus nitrogen and borax through spiral nozzle and fill nitrogen in hollow billet, its main function is removed by the residual oxidization skin in hollow billet, form a skim at the inner surface of hollow billet simultaneously, prevent hollow billet to be further oxidized;

(5), hot rolling: pipe of annealing introduces pipe mill hot rolling, and hot-rolled temperature is 1250 DEG C, obtains rolled pipe;

(6), sizing: the rolled pipe formed after tandem rolling is again through sizing mill sizing, and form steel pipe, finishing temperature control during sizing is at 850 DEG C;

(7), stress relief annealing: rolled pipe introduced heating in heating furnace and be incubated, come out of the stove with after stove cooling, obtain pipe of annealing, object is the intensity guaranteeing steel pipe, when annealing temperature is too high, processing strain recovers, can not obtain the effect of work hardening, annealing temperature is 650 DEG C, can obtain the effect of work hardening, in order to remove the strength variance of cold tube rolling, in the stove of cold tube rolling, the retention time is 20 minutes;

(8), pickling processes: annealing pipe is carried out pickling, removes the scale on surface, concentration of hydrochloric acid: 19%, pickling time: 60 minutes, then neutralization pond rolls, rolling number of times: 3 times, neutralizer pH value: 10, then roll through clear water reserviors, rolling number of times: 3 times;

(9), phosphorating treatment: the chemistry forming trbasic zinc phosphate on the surface of pipe generates overlay film, trbasic zinc phosphate concentration: 30%, Phosphating Solution temperature: 75 DEG C, phosphating time: 20 minutes, Phosphating Solution free acidity: 7, General Acidity in Phosphating Solution: 75;

(10), saponification process: form the lubricating film coateds such as metallic soap on overlay film, saponification temperature: 75 DEG C, saponification time: 15 minutes, saponification liquor pH value: 9;

(11), cold rolling: will treat that cold rolling pipe carries out cold rolling processing, and obtain cold rolled tube, the reciprocal time of the headstock of pipe mill is 30 times/min, and the length of at every turn sending to of pipe is 8mm/ time, obtains rolled pipe;

(12), heat treatment: the Technology for Heating Processing adopting tempering again after quenching, hardening heat is 800 DEG C, and hardening media is water, and temperature, at 550 DEG C, reduces the residual stress of drawn tube;

(13), pre-straightening process: straightening temperature 650 DEG C, to reduce residual stress;

(14), induction furnace Quenching Treatment: induction furnace hardening heat is 850 DEG C, and hardening media is water, reduces the residual stress of drawn tube;

(15), temper in batch-type furnace: the temperature of tempering air cooling is 400 DEG C, to reduce residual stress;

(16), honing: select vertical honing machine, workpiece turns round, and the form processing that honing head is reciprocating, reaches cylindricity: 0.02mm, Aperture deviation: 0.02mm, roughness: the high standard precision of Ra0.35;

(17), thermal straightening process: be incubated 60 minutes in low-temp temper furnace, carry out thermal straightening process again, thermal straightening temperature 550 DEG C, obtain yield strength (MPa): 895, tensile strength (MPa): 917, hardness (HV): 245, wall thickness tolerance: 8%, external diameter out-of-roundness: 0.3%, eccentricity: 6%, the cold rolling high-accuracy weldless steel tube of linearity: 0.30mm/m.

Embodiment three:

To prepare diameter for 140.4mm and the hole wall wall thickness 27SiMn steel pipe that is 8.3mm, comprise the following steps:

(1), heating: 27SiMn pipe is heated to 1240 DEG C in annular furnace, and the heat time is 3.5 hours, thus ensures that heating of pipe blank is even;

(2), bore a hole: heat pipe base perforated machine is bored a hole, the temperature of the hollow billet formed after perforation controls at 1120 DEG C, and order control punch eccentricity is 4%, visualize is carried out to pipe, use remove pipe surface burr, stick up skin, if pipe surface occurs or there is pit that significantly namely naked eyes are obvious, runs over and injure and crackle, then should reject, avoid flowing into subsequent processing, to control pipe surface quality;

(3), annealing: introduced in continuous annealing furnace by pipe and anneal, and order control annealing temperature is 550 DEG C, annealing time is 55min, obtains the annealing pipe that annealing hardness (HV) is 215;

(4), borax is sprayed: spray borax device blows to the descaling of hollow billet endoporus nitrogen and borax through spiral nozzle and fill nitrogen in hollow billet, its main function is removed by the residual oxidization skin in hollow billet, form a skim at the inner surface of hollow billet simultaneously, prevent hollow billet to be further oxidized;

(5), hot rolling: pipe of annealing introduces pipe mill hot rolling, and hot-rolled temperature is 1245 DEG C, obtains rolled pipe;

(6), sizing: the rolled pipe formed after tandem rolling is again through sizing mill sizing, and form steel pipe, finishing temperature control during sizing is at 825 DEG C;

(7), stress relief annealing: rolled pipe introduced heating in heating furnace and be incubated, come out of the stove with after stove cooling, obtain pipe of annealing, object is the intensity guaranteeing steel pipe, when annealing temperature is too high, processing strain recovers, can not obtain the effect of work hardening, annealing temperature is 600 DEG C, can obtain the effect of work hardening, in order to remove the strength variance of cold tube rolling, in the stove of cold tube rolling, the retention time is 15 minutes;

(8), pickling processes: annealing pipe is carried out pickling, removes the scale on surface, concentration of hydrochloric acid: 13%, pickling time: 45 minutes, then neutralization pond rolling, rolling number of times: 2.5 times, neutralizer pH value: 9.5, then through clear water reserviors rolling, rolling number of times: 2.5 times;

(9), phosphorating treatment: the chemistry forming trbasic zinc phosphate on the surface of pipe generates overlay film, trbasic zinc phosphate concentration: 25%, Phosphating Solution temperature: 70 DEG C, phosphating time: 15 minutes, Phosphating Solution free acidity: 6, General Acidity in Phosphating Solution: 55;

(10), saponification process: form the lubricating film coateds such as metallic soap on overlay film, saponification temperature: 65 DEG C, saponification time: 10 minutes, saponification liquor pH value: 8.5;

(11), cold rolling: will treat that cold rolling pipe carries out cold rolling processing, and obtain cold rolled tube, the reciprocal time of the headstock of pipe mill is 25 times/min, and the length of at every turn sending to of pipe is 7mm/ time, obtains rolled pipe;

(12), heat treatment: the Technology for Heating Processing adopting tempering again after quenching, hardening heat is 700 DEG C, and hardening media is water, and temperature, at 500 DEG C, reduces the residual stress of drawn tube;

(13), pre-straightening process: straightening temperature 550 DEG C, to reduce residual stress;

(14), induction furnace Quenching Treatment: induction furnace hardening heat is 800 DEG C, and hardening media is water, reduces the residual stress of drawn tube;

(15), temper in batch-type furnace: the temperature of tempering air cooling is 350 DEG C, to reduce residual stress;

(16), honing: select vertical honing machine, workpiece turns round, and the form processing that honing head is reciprocating, reaches cylindricity: 0.015mm, Aperture deviation: 0.015mm, roughness: the high standard precision of Ra0.28;

(17), thermal straightening process: be incubated 50 minutes in low-temp temper furnace, carry out thermal straightening process again, thermal straightening temperature 500 DEG C, obtain yield strength (MPa): 891, tensile strength (MPa): 908, hardness (HV): 240, wall thickness tolerance: 8%, external diameter out-of-roundness: 0.3%, eccentricity: 6%, the cold rolling high-accuracy weldless steel tube of linearity: 0.30mm/m.

Claims (1)

1. the manufacture method of a hot rolling high precision petroleum pipe comprises the steps:

(1), heating: 27SiMn pipe is heated to 1200 ~ 1280 DEG C in annular furnace, and the heat time is 3 ~ 4 hours, thus ensures that heating of pipe blank is even;

(2), bore a hole: heat pipe base perforated machine is bored a hole, the temperature of the hollow billet formed after perforation controls at 1100 ~ 1150 DEG C, and order control punch eccentricity and control pipe surface quality;

(3), annealing: introduced in continuous annealing furnace by pipe and anneal, and order control annealing temperature is 500 ~ 600 DEG C, annealing time is 50 ~ 60min, obtains the annealing pipe that annealing hardness (HV) is 210 ~ 217;

(4), borax is sprayed: spray borax device blows to the descaling of hollow billet endoporus nitrogen and borax through spiral nozzle and fill nitrogen in hollow billet, its main function is removed by the residual oxidization skin in hollow billet, form a skim at the inner surface of hollow billet simultaneously, prevent hollow billet to be further oxidized;

(5), hot rolling: pipe of annealing introduces pipe mill hot rolling, and hot-rolled temperature is 1240 ~ 1250 DEG C, obtains rolled pipe;

(6), sizing: the rolled pipe formed after tandem rolling is again through sizing mill sizing, and form steel pipe, finishing temperature control during sizing is at 800 ~ 850 DEG C;

(7), stress relief annealing: rolled pipe introduced heating in heating furnace and be incubated, come out of the stove with after stove cooling, obtain pipe of annealing, object is the intensity guaranteeing steel pipe, when annealing temperature is too high, processing strain recovers, can not obtain the effect of work hardening, annealing temperature is 550 ~ 650 DEG C, can obtain the effect of work hardening, in order to remove the strength variance of cold tube rolling, in the stove of cold tube rolling, the retention time is 10 ~ 20 minutes;

(8), pickling processes: annealing pipe is carried out pickling, removes the scale on surface, concentration of hydrochloric acid: 7 ~ 19%, pickling time: 35 ~ 60 minutes, then neutralization pond rolling, rolling number of times: 2 ~ 3 times, neutralizer pH value: 9 ~ 10, then through clear water reserviors rolling, rolling number of times: 2 ~ 3 times;

(9), phosphorating treatment: the chemistry forming trbasic zinc phosphate on the surface of pipe generates overlay film, trbasic zinc phosphate concentration: 20 ~ 30%, Phosphating Solution temperature: 68 ~ 75 DEG C, phosphating time: 10 ~ 20 minutes, Phosphating Solution free acidity: 4 ~ 7, General Acidity in Phosphating Solution: 45 ~ 75;

(10), saponification process: form the lubricating film coateds such as metallic soap on overlay film, saponification temperature: 55 ~ 75 DEG C, saponification time: 8 ~ 15 minutes, saponification liquor pH value: 8 ~ 9;

(11), cold rolling: will treat that cold rolling pipe carries out cold rolling processing, and obtain cold rolled tube, the reciprocal time of the headstock of pipe mill is 20 ~ 30 times/min, and the length of at every turn sending to of pipe is 6 ~ 8mm/ time, obtains rolled pipe;

(12), heat treatment: the Technology for Heating Processing adopting tempering again after quenching, hardening heat is 600 ~ 800 DEG C, and hardening media is water, and temperature, at 400 ~ 550 DEG C, reduces the residual stress of drawn tube;

(13), pre-straightening process: straightening temperature 500 ~ 650 DEG C, to reduce residual stress;

(14), induction furnace Quenching Treatment: induction furnace hardening heat is 750 ~ 850 DEG C, and hardening media is water, reduces the residual stress of drawn tube;

(15), temper in batch-type furnace: the temperature of tempering air cooling is 300 ~ 400 DEG C, to reduce residual stress;

(16), honing: select vertical honing machine, workpiece turns round, and the form processing that honing head is reciprocating, reaches cylindricity: 0.01 ~ 0.02mm, Aperture deviation: 0.01 ~ 0.02mm, roughness: the high standard precision of Ra0.25 ~ 0.35;

(17), thermal straightening process: be incubated 45 ~ 60 minutes in low-temp temper furnace, carry out thermal straightening process again, thermal straightening temperature 450 ~ 550 DEG C, obtain yield strength (MPa): 896, tensile strength (MPa): 918, hardness (HV): 250, wall thickness tolerance: 8%, external diameter out-of-roundness: 0.3%, eccentricity: 6%, the cold rolling high-accuracy weldless steel tube of linearity: 0.30mm/m.