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CN-116116902-B - Online preparation method of anti-oxidation coating on inner wall of seamless steel tube

CN116116902BCN 116116902 BCN116116902 BCN 116116902BCN-116116902-B

Abstract

The invention relates to an online preparation method of an anti-oxidation coating on the inner wall of a seamless steel pipe, which comprises the following steps of placing a steel billet heated to 1000-1300 ℃ on a perforation platform, enabling a plug and the steel billet to move relatively to conduct first perforation, conducting second perforation on the steel billet after the first perforation, and spraying anti-oxidation powder to the inner wall of the steel pipe by using a powder spraying device when the plug is immersed into the steel billet during the first perforation. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel pipe can realize that the anti-oxidation substance is sprayed to the inner wall of the steel pipe while the seamless steel pipe is perforated, so that the technical problem of serious oxidation of the inner wall of the steel pipe in the perforation process is solved in an online preparation mode, the quality of the inner wall of the seamless steel pipe is prevented from being damaged by the generated oxide skin in the subsequent perforation process, the polishing process is prevented from being increased, and even the steel pipe is scrapped.

Inventors

  • LI JIN
  • HUANG ZHONGJIA
  • LV ZHENGNAN
  • CHEN WEI
  • PANG DEYU

Assignees

  • 扬州诚德钢管有限公司

Dates

Publication Date
20260505
Application Date
20221031

Claims (8)

  1. 1. An online preparation method of an anti-oxidation coating on the inner wall of a seamless steel tube comprises the following steps: placing a billet heated to 1000 ℃ to 1300 ℃ on a piercing platform; Making the plug and billet relatively move to make first perforation; performing secondary perforation on the billet after the first perforation is completed; The method is characterized in that in the first perforation process, when the top is immersed into a steel billet, a powder spraying device is used for spraying anti-oxidation powder to the inner wall of the steel pipe, the powder spraying device comprises a top rod, the top rod is hollow and cylindrical, one end of the top rod is connected with the top head, a plurality of powder outlets are formed in the joint of the top rod and the top head, the powder outlets are communicated with a powder spraying machine through a powder feeding pipe arranged on the inner wall of the top rod, when the top head moves in the steel billet, the powder spraying machine conveys the anti-oxidation powder to the powder outlets through the powder feeding pipe, and sprays the anti-oxidation powder to the periphery, wherein the anti-oxidation powder consists of 40-45 parts by weight of benzene sulfinic acid, 53-59 parts by weight of graphite powder and 1-2 parts by weight of ethylcellulose, and is prefabricated into a spheroid mixture, and the particle diameter is 0.1-1.0 mm; The oxidation-resistant powder is softened into a film at the temperature of 750-900 ℃, is attached to the inner wall of the steel pipe, and plays roles in isolating oxygen and lubricating in the secondary perforation process.
  2. 2. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to claim 1, wherein the powder feeding tube is one and is arranged on the inner wall of the ejector rod, one end of the powder feeding tube is simultaneously communicated with a plurality of powder outlets, and the other end of the powder feeding tube is communicated with a powder spraying machine.
  3. 3. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to claim 1, wherein a plurality of powder feeding pipes are arranged corresponding to the powder outlets, the powder feeding pipes are arranged on the inner wall of the ejector rod, one end of each powder feeding pipe is respectively communicated with the corresponding powder outlet, and the other end of each powder feeding pipe is communicated with the powder spraying machine.
  4. 4. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to any one of claims 1 to 3, wherein the powder feeding tube is a steel tube.
  5. 5. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to any one of claims 1 to 3, wherein the plug and the ejector rod are connected through a connecting part.
  6. 6. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to claim 5, wherein the number of the powder outlets is 6, and the powder outlets are circumferentially and uniformly distributed on the connecting part.
  7. 7. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to any one of claims 1 to 3, wherein the powder outlet is connected with a face cover, and a plurality of jet ports are uniformly distributed on the face cover.
  8. 8. The online preparation method of the anti-oxidation coating on the inner wall of the seamless steel tube according to claim 7, wherein the diameter of the powder outlet is 30-50 mm, and the diameter of the jet orifice is 2-10 mm.

Description

Online preparation method of anti-oxidation coating on inner wall of seamless steel tube Technical Field The invention belongs to the field of seamless steel tube perforation, and particularly relates to the field of online preparation of an anti-oxidation coating on the inner wall of a seamless steel tube. Background The perforation process flow of the hot-rolled seamless steel tube comprises the following steps: solid round billet, heating, perforating, two-roller skew rolling, continuous rolling or extrusion, pipe removal, sizing (or reducing), cooling and pipe returning, straightening, hydrostatic testing (or flaw detection), marking and warehousing. In the process, the solid round billet of the steel pipe is generally heated to 1250 ℃, and the oxidation of the outer surface of the round billet of the product formed by one-time perforation has little influence on the quality of the steel pipe. However, the production of a large-diameter seamless steel pipe often requires 2 times of perforation, and the process is as follows: solid round billet, heating, perforation, secondary heating, secondary perforation, three-roller skew rolling, continuous rolling or extrusion, pipe removal, sizing (or reducing), pipe cooling and returning, straightening, hydrostatic test (or flaw detection), marking and warehousing. Because the tube blank temperature is high in the primary perforation process, the inner wall of the steel tube is oxidized after the primary perforation is finished, the high temperature of more than 1000 ℃ can lead to serious oxidization of the inner wall of the steel tube, the oxide skin is extruded by the plug to crush during the secondary perforation, and the broken oxide skin seriously scratches the inner wall of the steel tube in the secondary perforation process due to extremely high hardness of the oxide skin, so that the quality of the inner wall of the seamless tube is reduced, the problem that the inner wall of the seamless tube can be polished by a light person is solved, the polishing workload and the polishing dust pollution are increased, and the steel tube is scrapped due to serious scratch of the inner wall. In the prior art, the problem that the oxide scale is generated on the inner wall of the steel pipe during the first perforation is often that the steel pipe is treated after the first perforation is finished, and the formation of the oxide scale cannot be prevented or reduced during the perforation. Disclosure of Invention The invention aims to provide an online preparation method of an anti-oxidation coating on the inner wall of a seamless steel pipe, which solves the technical problem of serious oxidation of the inner wall of the steel pipe while perforating, avoids the generated oxide skin from damaging the quality of the inner wall of the seamless steel pipe in a secondary perforation process, and avoids the increase of a polishing process and even the rejection of the steel pipe. In order to achieve the purpose, the specific technical scheme of the online preparation method of the anti-oxidation coating for the inner wall of the seamless steel tube is as follows: An online preparation method of an anti-oxidation coating on the inner wall of a seamless steel tube comprises the following steps: placing a billet heated to 1000 ℃ to 1300 ℃ on a piercing platform; Making the plug and billet relatively move to make first perforation; performing secondary perforation on the billet after the first perforation is completed; When the first perforation is performed, when the top is immersed into the steel billet, the powder spraying device is used for spraying anti-oxidation powder to the inner wall of the steel pipe, the powder spraying device comprises a top rod, the top rod is hollow and cylindrical, one end of the top rod is connected with the top rod, a plurality of powder outlets are formed in the joint of the top rod and the top rod, the powder outlets are communicated with the powder spraying machine through a powder conveying pipe arranged on the inner wall of the top rod, the powder spraying machine conveys the anti-oxidation powder to the powder outlets through the powder conveying pipe when the top rod moves in the steel billet, and the anti-oxidation powder is sprayed to the periphery, wherein the anti-oxidation powder consists of 40-45 parts by weight of benzene sulfinic acid, 53-59 parts by weight of graphite powder and 1-2 parts by weight of ethylcellulose, and is prefabricated into a spheroid mixture, and the particle diameter is 0.1mm-1.0mm. Further, the powder feeding pipe is arranged on the inner wall of the ejector rod, one end of the powder feeding pipe is simultaneously communicated with the plurality of powder outlet ports, and the other end of the powder feeding pipe is communicated with the powder spraying machine. Further, the powder feeding pipes are correspondingly arranged in a plurality of powder outlet openings, the powder feeding pipes are arranged on t