CN1178152A

CN1178152A - Manufacture of stainless steel pipes with straight seam weld

Info

Publication number: CN1178152A
Application number: CN 97118714
Authority: CN
Inventors: 翟大军; 李树槐
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-09-16
Filing date: 1997-09-16
Publication date: 1998-04-08
Anticipated expiration: 2017-09-16
Also published as: CN1066356C

Abstract

A method for manufacturing stainless steel pipe with straight welded seam used in petrochemical industry and as oil delivery pipe includes such technological steps as cutting to prepare raw material, welding stainless steel plate, grinding welded seams, heating, rolling, welding, grinding welded seam, eddy inspection, straightening, stabilizing treatment, pressure test, and pickling, and features approximate chemical components and mechanical performance of welded seam with mother material, and low cost (40-50% of cost of seamless steel pipe). The finished pipe can replace the seamless stainless steel pipe in a certain condition.

Description

The manufacture method of stainless steel pipes with straight seam weld

The present invention relates to a kind of manufacture method that is used for the stainless steel pipes with straight seam weld of petrochemical industry production technology pipeline and oil transfer line.

At present, using a large amount of gapless stainless steel tubes in petroleum chemical enterprise's production technology and the commentaries on classics oil pipeline flow process.Because on material and the manufacturing process, particularly the gapless stainless steel tube price of ∮ more than 219 is very expensive for this kind steel pipe.In order to reduce investment and production cost, the on-the-spot actual general practice is: the employing gapless stainless steel tube of ∮ below 219; The employing composite seamless steel pipe (being bimetal tube) of ∮ 219-377; The employing clad steel plate pipe crimping of ∮ more than 426.But bimetal tube because bulge, lamination often take place two kinds of expansion of metal coefficient differences, makes its antiseptic property variation when mounted.And stainless compound steel plate when making two kinds of heterogeneity steel plate recombination rates have only 90%, simultaneously,, belong to the dissimilar steel welding because it is made up of two kinds of very big materials of composition difference, it is very big to weld difficulty, quality is uncontrollable.

The object of the present invention is to provide a kind of manufacture method of stainless steel pipes with straight seam weld of the alternative gapless stainless steel tube use that not only can guarantee product quality, performance but also can reduce production costs under certain condition.

The present invention realizes like this.This manufacture method comprises that cutting is got the raw materials ready, steel plate welding, polish weldering meat, heat weld seam, roll cylinder, welded still pipe, polish operations such as weld seam, eddy current inspection, aligning shaping, stabilization processes, pressure testing check and pickling processes, and the preface of constructing in fact step is as follows:

1. cutting is got the raw materials ready.Press the different tube diameters specification and calculate materials, line adopt machinery or plasma method cutting steel plate, and finished edge is standby;

2. steel plate welding.With the acknowledgment copy that cuts into splicing (∮ 480 following pipes need not splice), and blanketing with inert gas pad and automatic TIG welding machine weld in argon gas track protection process;

3. polish weldering meat.With PDA molding sand wheel, will weld the meat rubbing down to concordant with mother metal;

4. heating weld seam.Adopt electrical resistance heating weld seam and heat affected area to be heated to more than 900 ℃ constant temperature 20 minutes;

5. roll cylinder.Steel plate is delivered in the DQZ001 shaping machine set of being changed a social system by W11-20 * 2500 type three rolls plate bending machines, rolled into the required size cylinder;

6. welded still pipe.Blanketing with inert gas pad and automatic TIG welding machine are welded into steel pipe in argon gas track protection process in cylinder;

7. polish weld seam.With PDA molding sand wheel that the weld seam rubbing down is extremely concordant with mother metal;

8. eddy current inspection.Adopt probe coil that steel pipe seam is carried out eddy current inspection;

9. aligning shaping.Steel pipe placed carry out shapings such as sizing, tack, aligning on the DQZ001 shaping machine set;

10. stabilization processes.Steel pipe after the shaping is heated to more than 900 ℃, and constant temperature 20 minutes carries out air cooling then;

11. pressure testing check.Steel pipe after the stabilization processes is placed on the hydrostatic testing machine, and by the Zhi Jinhang water pressure test, its pressure should be greater than 2.45MPa.As required, also available 300KV-X light ray machine check seam organization;

12. pickling processes.The steel pipe that pressure testing is up to the standards carries out pickling processes.

Stainless steel pipes with straight seam weld manufacture method provided by the invention can make chemical analysis, mechanical performance and the mother metal of steel pipe seam close, can guarantee the quality of product, and can be lower than 500 ℃, pressure in medium temperature and be lower than and replace gapless stainless steel tube in petroleum chemical enterprise's process pipelines, to use under the 2.0MPa condition, and its manufacturing cost only is the 40-50% of gapless stainless steel tube, is suitable for and applies.

Utilize method provided by the invention can make the stainless steel pipes with straight seam weld series of products of external diameter ∮ 219-720mm, wall thickness 4-20mm, its joint length is 6m.

Claims

1. the manufacture method of a stainless steel pipes with straight seam weld is characterized in that, this manufacture method is implemented by following process:

(1) cutting is got the raw materials ready and is calculated materials by the different tube diameters specification, line, and employing machine or plasma method cutting steel plate, and finished edge is standby;

(2) the steel plate welding acknowledgment copy splicing that will cut into, and blanketing with inert gas pad and automatic TIG welding machine weld in argon gas track protection process;

(3) polish the meat PDA molding sand wheel of weldering, will weld the meat rubbing down to concordant with mother metal;

(4) the heating weld seam adopts electrical resistance heating weld seam and heat affected area to be heated to more than 900 ℃ constant temperature 20 minutes;

(5) roll cylinder steel plate is delivered to by W11-20 * 2500 type three rolls plate bending machines, in the DQZ001 shaping machine set of the transformation of the way, roll into the required size cylinder;

(6) welded still pipe blanketing with inert gas pad and automatic TIG welding in cylinder is welded into steel pipe in argon gas track protection process;

(7) polishing weld seam takes turns the weld seam rubbing down to concordant with mother metal with the PDA molding sand;

(8) eddy current inspection adopts probe coil that steel pipe seam is carried out eddy current inspection;

(9) the aligning shaping places the DQZ001 shaping machine set to carry out shapings such as sizing, tack, aligning steel pipe;

(10) steel pipe of stabilization processes after with shaping is heated to more than 900 ℃, and constant temperature 20 minutes carries out air cooling then;

(11) pressure testing check places the steel pipe after the stabilization processes on the hydrostatic testing machine, and by the Zhi Jinhang water pressure test, its pressure should be greater than 2.45MPa, as required, and available 300KV-X light ray machine check seam organization;

(12) pickling processes is carried out pickling processes to the steel pipe that pressure testing is up to the standards.