KR20130077924A - Uoe steel pipe and manufacturing method theheof - Google Patents

Uoe steel pipe and manufacturing method theheof Download PDF

Info

Publication number
KR20130077924A
KR20130077924A KR1020110145203A KR20110145203A KR20130077924A KR 20130077924 A KR20130077924 A KR 20130077924A KR 1020110145203 A KR1020110145203 A KR 1020110145203A KR 20110145203 A KR20110145203 A KR 20110145203A KR 20130077924 A KR20130077924 A KR 20130077924A
Authority
KR
South Korea
Prior art keywords
pipe
steel pipe
coating
uoe steel
uoe
Prior art date
Application number
KR1020110145203A
Other languages
Korean (ko)
Other versions
KR101360689B1 (en
Inventor
김영훈
조민현
한승훈
양승우
Original Assignee
주식회사 포스코
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 포스코 filed Critical 주식회사 포스코
Priority to KR1020110145203A priority Critical patent/KR101360689B1/en
Publication of KR20130077924A publication Critical patent/KR20130077924A/en
Application granted granted Critical
Publication of KR101360689B1 publication Critical patent/KR101360689B1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
    • C23C4/14—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying for coating elongate material
    • C23C4/16—Wires; Tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/08—Making tubes with welded or soldered seams
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/06—Metallic material
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
    • C23C4/134—Plasma spraying

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Articles (AREA)

Abstract

PURPOSE: An u-press o-press expansion (UOE) steel pipe and a manufacturing method thereof are provided to perform a coating process so that compressive stress is given to the entire outer surfaces of pipe or the outer surface of UOE steel pipe on which the tension residual stress generated by at least one process of forming, welding, expansion processes exists. CONSTITUTION: A manufacturing method of UOE steel pipe includes a pipe forming process in which a steel plate is formed in a pipe shape, a welding process in which the formed pipe is welded, a pipe expanding process in which the welded pipe is expanded, and a coating process in which the expanded pipe is coated. The coating process is performed so that compressive stress is given to the entire outer surfaces of pipe or the outer surface of UOE steel pipe on which the tension residual stress generated by at least one process of the pipe forming, welding, pipe expanding processes exists. The compressive stress that is given by the coating has the magnitude of 80 to 120% of tension residual stress formed on the surface of the UOE steel pipe. [Reference numerals] (AA) Coating unit (tow unit); (BB) Coating unit (an entire welding part including a heat affected part); (CC) Coating unit (an entire external surface)

Description

ＵＯＥ 강관 및 그 제조방법{UOE STEEL PIPE AND MANUFACTURING METHOD THEHEOF}VOE steel pipe and its manufacturing method {UOE STEEL PIPE AND MANUFACTURING METHOD THEHEOF}

본 발명은 기계적 특성이 우수한 UOE강관 및 그 제조방법에 관한 것이다. The present invention relates to a UOE steel pipe excellent in mechanical properties and a method of manufacturing the same.

최근 석유나 천연가스와 같은 천연 자원의 가격 상승이나 고갈로 인하여 그러한 자원들의 개발 구역이 점차 한랭지로 이동하기 시작하였다. 따라서 이러한 한랭지에서 천연가스나 오일을 수송하는 장거리의 파이프라인의 파괴는 중대한 사고로 연결된다. 상기 파이프라인으로는 고강도 강으로 이루어지는 UOE 강관 등이 사용되고 있다. 이러한 UOE강관은 파괴 안전성을 확보하는 것이 가장 중요하다.
Recently, due to the rising or depletion of the price of natural resources such as oil and natural gas, the development zone of such resources gradually began to move to cold districts. Thus, the destruction of long-distance pipelines carrying natural gas or oil in these cold regions leads to serious accidents. As the pipeline, a UOE steel pipe made of high strength steel or the like is used. It is most important for these UOE steel pipes to have breaking safety.

UOE강관 조관시 필수적으로 사용되는 용접공정에 의하여 도 2에 나타난 바와 같이, 파이프 외면에는 인장잔류응력이 존재하고, 파이프 내면에는 압축잔류응력이 존재하게 된다. 그 중에서, 용접열영향부(HAZ) 특히, 용접토우(toe)부는 용접열원에 의하여 급열 및 급냉 상황을 겪게 되는데, 이로 인하여, 용접부 토우부의 외면에는 파이프 외면 보다 많은 인장잔류응력이 존재하고, 용접부 토우부의 내면에는 파이프 내면 보다 많은 잔류응력이 존재된다. 즉, 용접토우(toe)부는 금속조직학적으로 결정립이 조대화되거나 취약한 조직으로 상변태가 일어나는 경우가 많다.
As shown in FIG. 2 by the welding process used during the tubing of UOE steel pipe, the tensile residual stress exists on the outer surface of the pipe, and the compression residual stress exists on the inner surface of the pipe. Among them, the welding heat affected zone (HAZ), in particular, the welding toe portion undergoes a quenching and quenching condition due to the welding heat source. Therefore, the tensile residual stress of the welding toe portion is greater than that of the pipe outer surface. More residual stress exists on the inner surface of the tow than on the inner surface of the pipe. In other words, the welding toe portion is often metallographically coarsened or vulnerable to phase transformation.

따라서 용접토우(toe)부는 일반적으로 모재에 비하여 기계적 성질의 열화가 발생하고, UOE강관의 강도 및 저온인성과 같은 파이프 전체의 균일한 물성 확보에 있어 언제나 용접토우(toe)부의 문제가 제기된다.
Therefore, the weld toe is generally deteriorated in mechanical properties compared to the base material, and the problem of the weld toe is always raised in securing uniform properties of the entire pipe such as the strength and low temperature toughness of the UOE steel pipe.

지금까지, UOE조관은 판재에서의 파이프 조관을 하는 과정에서 잔류응력이 발생하였다. 특히, 극후물화에 따른 잔류응력 발생이 파이프 전체의 균일한 물성 확보에 있어 심각한 문제가 되고 있어, 후공정을 통하여 잔류응력 제거를 실시하였다.
Until now, UOE pipes had residual stresses in the process of pipe pipes. In particular, residual stress caused by extreme thickening is a serious problem in securing uniform physical properties of the entire pipe, and the residual stress is removed through a post process.

후공정은 피닝(peening) 및 열처리 등이 있는데, 피닝을 실시하는 경우에는 표면특성이 저하되는 문제가 발생되며, 열처리 공정을 실시하는 경우에는 고가의 설비투자 및 유지비 등 경제적이지 못하다.
Post-processing includes peening and heat treatment. When the peening is performed, a problem occurs that the surface characteristics are deteriorated, and when the heat treatment is performed, expensive equipment investment and maintenance costs are not economical.

이와 같은 후공정은 잔류응력을 제거하는 일부 효과는 있으나, 파이프 전체의 균일한 물성 확보에는 무리가 있다.Such a post process has some effects of removing residual stress, but it is unreasonable to ensure uniform physical properties of the entire pipe.

본 발명은 파이프 전체의 균일한 물성 확보를 가능하게 하고, 더불어 내마모성 특성 확보가 가능한 UOE강관 및 그 제조방법을 제공하고자 한다.The present invention is to provide a uniform physical properties of the entire pipe, and to provide a UOE steel pipe and a method of manufacturing the same that can ensure the wear resistance properties.

본 발명의 일측면인 UOE강관 제조방법은 강판을 관형상으로 조관하는 조관공정, 조관된 관을 용접하는 용접공정, 용접된 관을 확관하는 확관공정 및 상기 확관된 강관을 코팅하는 코팅공정을 포함하고, 상기 코팅공정은 상기 강관의 외면전체 또는 상기 조관공정, 용접공정 및 확관공정 중의 적어도 하나의 공정에 의해 발생된 인장잔류응력이 존재하는 UOE강관의 외부면에 압축응력을 부여하도록 코팅하는 것을 특징으로 한다.
UOE steel pipe manufacturing method, which is an aspect of the present invention, includes a tubing process for steel sheet tubular tubing, a welding process for welding the welded pipe, an expansion process for expanding the welded pipe, and a coating process for coating the expanded steel pipe. The coating process is to coat the entire outer surface of the steel pipe or the outer surface of the UOE steel pipe in which the tensile residual stress generated by at least one of the pipe forming process, the welding process and the expansion process is present to give a compressive stress. It features.

본 발명의 다른 일측면인 UOE강관은 표면에 코팅층이 형성된 UOE강관으로서, 상기 코팅층은 그 두께가 350~450㎛이고, 코팅 전 강관 내 인장잔류응력이 존재하는 부위에 형성되어 압축응력을 부여한다.
Another aspect of the present invention is a UOE steel pipe is a UOE steel pipe with a coating layer formed on the surface, the coating layer is 350 ~ 450㎛ thickness, is formed in the portion where the tensile residual stress in the steel pipe before coating gives a compressive stress .

덧붙여 상기한 과제의 해결수단은, 본 발명의 특징을 모두 열거한 것은 아니다. 본 발명의 다양한 특징과 그에 따른 장점과 효과는 아래의 구체적인 실시형태를 참조하여 보다 상세하게 이해될 수 있을 것이다. In addition, the solution of the said subject does not enumerate all the features of this invention. Various features of the present invention and the advantages and effects thereof may be understood in more detail with reference to the following specific embodiments.

본 발명에 의하면, UOE강관 제작시 판재에서 파이프 조관을 하는 과정에서 발생하는 인장잔류응력을 상쇄시켜 UOE조관 전체의 균일한 물성 확보가 가능하다. 더불어 내마모특성을 확보함으로써, 강관의 운영, 운송 및 설치시 발생할 수 있는 표면 긁힘, 노치 등과 같은 결함방생을 방지할 수 있고, 또한 이로 인하여, 매립 혹은 설치 후 장기간 사용시 파이프 외면의 내식성을 향상시키는 효과가 있다.According to the present invention, it is possible to secure uniform physical properties of the entire UOE pipe by offsetting the tensile residual stress generated in the process of pipe piping in the plate during the production of UOE steel pipe. In addition, by securing the wear resistance, it is possible to prevent the occurrence of defects such as surface scratches, notches, etc. that can occur during the operation, transportation and installation of the steel pipe, and also to improve the corrosion resistance of the outer surface of the pipe during long-term use after embedding or installation It works.

도 1은 통상의 UOE강관의 제조방법에 관한 모식도이다.
도 2는 조관후 파이프 잔류응력에 관한 모식도이다.
도 3은 용접후 잔류응력을 나타낸 사진이다.
도 4는 코팅 후 잔류응력상태를 나타내는 모식도이다.
도 5는 본 발명에 따른 코팅 모습을 나타낸 사진이다.1 is a schematic diagram of a manufacturing method of a conventional UOE steel pipe.
2 is a schematic diagram of the residual pipe stress after piping.
Figure 3 is a photograph showing the residual stress after welding.
4 is a schematic diagram showing the residual stress state after coating.
5 is a photograph showing the appearance of the coating according to the present invention.

본 발명자들은 잔류응력의 제거를 통한 파이프 전체의 균일한 물성을 갖는 UOE강관을 도출해내기 위하여 연구를 행한 결과, 확관공정 후에, 상기 조관공정, 용접공정 및 확관공정 중의 적어도 하나의 공정에서 발생되는 인장 잔류응력을 제거하기 위하여 외부면에 압축응력을 부여하도록 코팅함으로써, 기계적 특성이 우수한 UOE강관을 생산할 수 있음을 확인하고 본 발명에 이르게 되었다.
The present inventors conducted a study to derive a UOE steel pipe having uniform physical properties of the entire pipe through the removal of residual stress, and after the expansion process, the tension generated in at least one of the pipe forming process, the welding process and the expansion process. By applying a compressive stress to the outer surface in order to remove the residual stress, it was confirmed that it can produce a UOE steel pipe with excellent mechanical properties and led to the present invention.

이하, 본 발명의 일측면인 UOE강관 제조방법에 대하여 상세히 설명한다.
Hereinafter, a method for manufacturing a UOE steel pipe which is one aspect of the present invention will be described in detail.

상기 UOE강관은 도 1에 나타난 바와 같이, 강판의 엣지 밀링(edge milling), 엣지 크림핑(edge crimping), 유형성형(U-ing) 및 오형성형(O-ing)을 포함하는 조관공정, 용접공정 및 확장공정(expansion)을 통하여 제조된다.
As shown in FIG. 1, the UOE steel pipe is welded by welding, including edge milling, edge crimping, type forming (U-ing), and mold forming (O-ing) of steel sheets. Manufactured through process and expansion.

조관공정에서는 도 2에 나타난 바와 같이, 관의 외면에서는 강판이 인장되며, 내면에서는 강판이 압축되어 강판의 내·외면의 응력차이가 발생하게 되어 강관의 외면에 인장잔류응력이 발생하게 된다.
In the tube manufacturing process, as shown in FIG. 2, the steel sheet is tensioned on the outer surface of the tube, and the steel sheet is compressed on the inner surface to generate a stress difference between the inner and outer surfaces of the steel sheet, thereby generating a tensile residual stress on the outer surface of the steel pipe.

상기와 같이 조관 한 다음, 용접을 행하는데 이때, 용접부 토우부 및 열영향부를 포함하는 용접부 전체에 인장잔류응력이 발생하게 된다.
After the tubing as described above, the welding is performed, the tensile residual stress is generated in the entire welded portion including the welded toe and the heat affected zone.

상기 코팅에 의해 부여되는 압축응력은 상기 UOE강관의 표면에 형성된 인장잔류응력의 80~120%의 크기를 갖는 것이 바람직하다. 더불어, 압축응력의 크기는 상기 인장잔류응력을 상쇄할 정도인 것이 보다 바람직하다.
The compressive stress imparted by the coating preferably has a size of 80 to 120% of the tensile residual stress formed on the surface of the UOE steel pipe. In addition, the magnitude of the compressive stress is more preferably enough to offset the tensile residual stress.

본 발명에서의 토우부는 도 5의 (a)에 나타난 바와 같이, 외부용접부의 끝부분을 의미한다.
Tow in the present invention means the end of the outer welding portion, as shown in Figure 5 (a).

도 3에 나타난 바와 같이, 용접 후에는 특히 용접부 토우부에 가장 큰 인장잔류응력이 발생됨을 알 수 있다.
As shown in FIG. 3, it can be seen that after welding, the largest tensile residual stress is generated, in particular, the weld toe portion.

상기와 같이 용접 한 후 행해지는 확관시에도 인장잔류응력이 강관의 외부에 발생된다.
Tensile residual stress is also generated on the outside of the steel pipe when the expansion is performed after welding as described above.

이러한 인장잔류응력을 상쇄시키기 위하여, 본 발명에서는 도 5에 나타난 바와 같이, 관의 외부면 또는 강관 외면 전체에 코팅을 행하는 것이 바람직하다.
In order to offset such tensile residual stress, in the present invention, it is preferable to coat the outer surface of the tube or the entire outer surface of the steel pipe as shown in FIG. 5.

도 5의 (a)는 용접부 토우부를 코팅한 것을 나타내고, 도 5의 (b)는 열영향부를 포함한 용접부 전체를 코팅한 것을 나타내며, 도 5의 (c)는 파이프 전체를 코팅한 것을 나타낸다.
FIG. 5A shows that the welded tow portion is coated, and FIG. 5B shows the entire welded portion including the heat affected zone, and FIG. 5C shows the entire pipe.

상기 관의 외부면은 외부 용접부 토우부 및 열영향부를 포함하는 용접부 전체 중 적어도 하나의 부분인 것이 바람직하다.
The outer surface of the tube is preferably at least one portion of the entire weld, including an external weld tow and a heat affected zone.

특히, 조관공정, 용접공정과 확관공정을 거치게 되면서 잔류응력문제가 심각하게 부각 되는 외부 용접부 토우부에 코팅되는 것이 보다 바람직하다.
In particular, it is more preferable to be coated on the outer tow portion of the external welded part, which undergoes the pipe making process, the welding process, and the expanding process, in which the residual stress problem is seriously highlighted.

상기 코팅은 Cr+W-C:H, Cr+W-C:H+DLC, CrN+W-C:H+DLC, Cr+W-C:H+Si=DLC, Cr+W-C:H+ta-C로 이루어진 그룹에서 1종 이상의 코팅재료를 사용하여 코팅하는 것이 바람직하다. 상기와 같은 코팅 재료는 강판표면에 코팅된 후 수축에 의하여 강판 표면에 압축응력을 부여하는 효과를 가진다. 뿐만 아니라 상기 코팅재가 가지는 경도로 인하여 강판 표면에 내마모성을 부여하는 효과도 가지는 것이다.
The coating is one kind in the group consisting of Cr + WC: H, Cr + WC: H + DLC, CrN + WC: H + DLC, Cr + WC: H + Si = DLC, Cr + WC: H + ta-C It is preferable to coat using the above coating material. The coating material as described above has the effect of imparting a compressive stress on the surface of the steel sheet by shrinkage after being coated on the surface of the steel sheet. In addition, due to the hardness of the coating material is to have an effect of providing abrasion resistance to the surface of the steel sheet.

상기 코팅시 코팅방법은 압축응력을 부여할 수 있는 코팅방법이라면, 특별히 제한되는 것은 아니다. 다만 몇 가지 비제한적이 예를 든다면 플라즈마 스프레이법, 기체상 도금법 및 액적 분사법 중 1종 이상의 방법이 바람직하다.
The coating method during the coating is not particularly limited as long as it is a coating method capable of imparting compressive stress. However, if some non-limiting examples are given, one or more methods of the plasma spray method, the gas phase plating method, and the droplet injection method are preferable.

또한, 상기 코팅시 코팅온도는 80~800℃인 것이 바람직하다. 코팅온도가 80℃미만인 경우에는 코팅재료가 강관에 충분히 결합하지 못한다. 반면에, 800℃를 초과하는 경우에는 코팅재료의 변형이 생기는 문제가 있다. 따라서, 상기 코팅 온도는 80~800℃에서 행하는 것이 바람직하다. 보다 바람직한 코팅온도는 80~ 300℃이다.
In addition, the coating temperature during the coating is preferably 80 ~ 800 ℃. If the coating temperature is less than 80 ℃ coating material is not sufficiently bonded to the steel pipe. On the other hand, if it exceeds 800 ℃ there is a problem that the deformation of the coating material occurs. Therefore, it is preferable to perform the said coating temperature at 80-800 degreeC. More preferable coating temperature is 80-300 degreeC.

본 발명의 다른 일측면인 UOE강관에 관하여 상세히 설명한다.
Another aspect of the present invention will be described in detail with respect to the UOE steel pipe.

본 발명의 다른 일측면인 UOE강관은 표면에 코팅층이 형성된 UOE강관으로서, 상기 코팅층은 그 두께가 350~450㎛이고, 코팅 전 강관 내 인장잔류응력이 존재하는 부위에 형성되어 압축응력을 부여한다.
Another aspect of the present invention is a UOE steel pipe is a UOE steel pipe with a coating layer formed on the surface, the coating layer is 350 ~ 450㎛ thickness, is formed in the portion where the tensile residual stress in the steel pipe before coating gives a compressive stress .

상기 코팅층의 두께는 350~450㎛인 것이 바람직하다. The thickness of the coating layer is preferably 350 ~ 450㎛.

상기 코팅층의 두께에 의하여 UOE 강관의 내마모성 및 부식성 등의 특성이 변화하므로 코팅층의 두께를 조정하여야 한다. 내마모성, 부식성 및 박리를 방지하기 위하여 상기 코팅층의 두께는 350㎛이상으로 제어하는 것이 바람직하다. 내마모성 향상 효과 및 경제성을 고려하여 상기 코팅층의 두께의 상한은 450㎛로 제어하는 것이 바람직하다.
Since the characteristics such as wear resistance and corrosion resistance of the UOE steel pipe is changed by the thickness of the coating layer, the thickness of the coating layer should be adjusted. In order to prevent wear resistance, corrosion and peeling, the thickness of the coating layer is preferably controlled to 350 μm or more. In consideration of the effect of improving wear resistance and economical efficiency, the upper limit of the thickness of the coating layer is preferably controlled to 450 μm.

또한, 코팅에 의해 UOE강관의 평균 마모속도는 종래재에 비하여 현저히 감소될수 있다. 즉, 통상의 경우는 2.3x10-6~4.0x10-6mm3N-1m-1수준이다. 본 발명과 같은 방식으로 코팅층을 형성할 경우 0.5x10-6 ~ 2.0x10-6mm3N-1m-1까지 감소시킬 수 있다.
In addition, the average wear rate of UOE steel pipes by coating can be significantly reduced compared to conventional materials. That is, in the usual case, the level is 2.3 × 10 −6 to 4.0 × 10 −6 mm 3 N −1 m −1 . When the coating layer is formed in the same manner as in the present invention, the coating layer may be reduced to 0.5 × 10 −6 to 2.0 × 10 −6 mm 3 N −1 m −1 .

상기 코팅에 의해 부여되는 압축응력은 상기 UOE강관의 표면에 형성된 인장잔류응력의 80~120%의 크기를 갖는 것이 바람직하다. 더불어, 압축응력의 크기는 상기 인장잔류응력을 상쇄할 정도인 것이 보다 바람직하다.
The compressive stress imparted by the coating preferably has a size of 80 to 120% of the tensile residual stress formed on the surface of the UOE steel pipe. In addition, the magnitude of the compressive stress is more preferably enough to offset the tensile residual stress.

도 4의 (a)는 코팅층과 강판, 두 판재의 결합을 나타낸 것이고, 도 4의 (b)는 상기 두 판재의 스트레인 미스핏(Strain Misfit: Δε)이 발생한 경우를 나타낸 것이다. 또한, 도 4의 (c)는 두 판재간의 반대되는 동일한 힘(-P 와 P)이 발생하여 미스핏이 상쇄되는 것을 나타낸 것이고, 도 4의 (d)는 (c)의 결과 불균형적인 모멘트가 발생하는 것을 나타낸 것이다.
Figure 4 (a) shows the coupling between the coating layer and the steel sheet, two plates, Figure 4 (b) shows a case where the strain Misfit (Δε) of the two plates occurs. In addition, (c) of FIG. 4 shows that the opposite forces (-P and P) between the two plates are generated to cancel the misfit, and (d) of FIG. 4 shows that an unbalanced moment is obtained as a result of (c). It shows what happens.

도 4에 나타난 바와 같이, 상기 코팅재료에 열을 가하여 열 전도도(α)와 온도 구배(?T)에 의하여 스트레인 미스핏(Strain misfit)발생에 의하여 강관 내 압축잔류응력이 전이됨으로써, 관의 외부면의 인장 잔류응력을 감소시키는 것이 가능하다. 보다 바람직하게는 상기 코팅에 의해 부여되는 압축응력은 관의 외부면의 인장 잔류응력을 상쇄할 정도의 크기를 가지는 것이 바람직하다. 상기와 같은 압축응력의 부여조건은 코팅재의 종류, 두께, 열처리 온도 등에 따라 달라지며 본 발명이 속하는 기술 분야의 통상적인 지식을 가지는 자라면 상기 조건을 충적하도록 용이하게 코팅층을 형성할 수 있을 것이다.
As shown in Figure 4, by applying heat to the coating material by the thermal conductivity (α) and the temperature gradient (? T) by the strain misfit (Strain misfit) generated by the compressive residual stress in the steel pipe, the outside of the pipe It is possible to reduce the tensile residual stress of the face. More preferably, the compressive stress imparted by the coating is large enough to offset the tensile residual stress of the outer surface of the tube. The conditions for imparting compressive stress as described above depend on the type, thickness, heat treatment temperature, etc. of the coating material, and a person having ordinary knowledge in the art to which the present invention pertains may easily form a coating layer to satisfy the above conditions.

이하, 실시예를 통하여 본 발명을 보다 구체적으로 설명하고자 한다. 다만, 하기의 실시예는 본 발명을 예시하여 보다 상세하게 설명하기 위한 것일 뿐, 본 발명의 권리범위를 한정하기 위한 것이 아니라는 점에 유의할 필요가 있다. 본 발명의 권리범위는 특허청구범위에 기재된 사항과 이로부터 합리적으로 유추되는 사항에 의해 결정되는 것이기 때문이다.
Hereinafter, the present invention will be described more specifically by way of examples. It should be noted, however, that the following examples are intended to illustrate the invention in more detail and not to limit the scope of the invention. The scope of the present invention is determined by the matters set forth in the claims and the matters reasonably inferred therefrom.

(실시예)(Example)

발명예Honor 1 One

두께 18㎜, 폭 2400㎜, 길이 1000㎜의 강판을 엣지 밀링하여 개선면을 형성하고, 이후 엣지 크림핑, 유형 성형, 오형 성형을 포함하는 과정으로 조관하였다. 조관된 강관에 대하여 용접을 실시한 후 확관하여 UOE강관을 제조하였다. 상기 UOE강관의 전체면을 Cr+W-C:H 코팅재료를 이용하여 280℃에서 플라즈마 스프레이 법에 의해 코팅하였다. 코팅후 코팅재료의 두께는 400㎛이었다. 상기 코팅된 강관을 마찰시험으로 건전성을 평가하였다. 마찰시험기는 회전식 볼 타입으로 회전식 볼은 200Hv의 경도값을 가지는 9.53mm 직경의 황동(brass) 소재를 사용하였으며 하중은 2N, 회전속도는 0.5m/s, 총 회전거리는 5000m를 수행하였다. 시험후 마모량은 마모부위의 cross-section 면적을 측정하였다. 총 10회 실시결과, 평균 마모속도는 1 x 10-6 mm3N-1m- 1결과를 얻었다
A steel sheet having a thickness of 18 mm, a width of 2400 mm, and a length of 1000 mm was edge milled to form an improved surface, and then, it was produced by a process including edge crimping, type molding, and mold molding. The welded steel pipe was welded and then expanded to manufacture a UOE steel pipe. The entire surface of the UOE steel pipe was coated by a plasma spray method at 280 ℃ using Cr + WC: H coating material. The thickness of the coating material after coating was 400 μm. The coated steel pipe was evaluated for integrity by a friction test. The friction tester was a rotary ball type, and the rotary ball was a brass material of 9.53mm diameter having a hardness value of 200 Hv. The load was 2N, the rotation speed was 0.5m / s, and the total rotation distance was 5000m. The amount of wear after the test was measured by the cross-section area of the wear site. As a result of a total of 10 tests, the average wear rate was 1 x 10 -6 mm 3 N -1 m - 1

발명예Honor 2 2

코팅되는 부위를 열영향부를 포함하는 용접부 전체로 한정한 것 이외에는 상기 발명예 1과 동일한 방식으로 UOE강관의 외면에 코팅층을 형성하고 마찰시험을 행하였다. 총 10회 실시결과, 평균 마모속도는 1.23 x 10-6 mm3N-1m-1의 값을 얻었다.
A coating layer was formed on the outer surface of the UOE steel pipe in the same manner as in Inventive Example 1 except that the coated part was limited to the entire welded part including the heat affected part, and a friction test was performed. As a result of a total of 10 runs, the average wear rate was 1.23 x 10 -6 mm 3 N -1 m -1 .

발명예Honor 3 3

코팅되는 부위를 용접부 토우부로 한정한 것 이외에는 상기 발명예 1과 동일한 방식으로 UOE강관의 외면에 코팅층을 형성하고 마찰시험을 행하였다. 총 10회 실시결과, 평균 마모속도는 1.12 x 10-6 mm3N-1m-1의 값을 얻었다.
Except for limiting the coated portion to the welded toe portion, the coating layer was formed on the outer surface of the UOE steel pipe in the same manner as in Inventive Example 1 and subjected to a friction test. As a result of a total of 10 tests, the average wear rate was 1.12 x 10 -6 mm 3 N -1 m -1 .

종래예Conventional example

코팅을 실시하지 않은 것 이외에는 상기 발명예 1과 동일한 방식으로 UOE강관을 제조하고 마찰시험을 행하였다. 총 10회 실시결과, 평균 마모속도는 2.36 x 10-1 mm3N-1m-1의 값을 얻었다.
A UOE steel pipe was manufactured and subjected to a friction test in the same manner as in Inventive Example 1 except that no coating was performed. As a result of a total of 10 runs, the average wear rate was 2.36 x 10 -1 mm 3 N -1 m -1 .

상기 발명예 1 내지 3의 결과와 종래예의 결과로부터 알 수 있듯이 강관의 외면에 코팅을 실시한 발명예의 경우가 훨씬 개선된 파괴특성을 나타냄을 알 수 있었다. 특히, 전체면에 코팅을 실시한 것이 일부에 대해 실시한 것 보다 우수하며, 일부에 코팅한 것 중에서도 열영향부를 포함하는 용접부 전체에 코팅한 것이 토우부만 코팅한 것에 비해서 양호한 결과를 나타내고 있었다.
As can be seen from the results of Inventive Examples 1 to 3 and the results of the conventional example, it was found that the case of the Inventive Example coated on the outer surface of the steel pipe showed much improved fracture characteristics. In particular, the coating on the whole surface was superior to that on the part, and the coating on the entire welded part including the heat-affected part among the parts coated on the part showed better results than the tow part only.

따라서, 본 발명의 유리한 효과를 확인할 수 있었다.
Therefore, the advantageous effects of the present invention can be confirmed.

이상 실시예를 참조하여 설명하였지만, 해당 기술 분야의 숙련된 당업자는 하기의 특허 청구의 범위에 기재된 본 발명의 사상 및 영역으로부터 벗어나지 않는 범위 내에서 본 발명을 다양하게 수정 및 변경시킬 수 있음을 이해할 수 있을 것이다.It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (8)

강판을 관형상으로 조관하는 조관공정, 조관된 관을 용접하는 용접공정, 용접된 관을 확관하는 확관공정 및 상기 확관된 강관을 코팅하는 코팅공정을 포함하고, 상기 코팅공정은 상기 강관의 외면전체 또는 상기 조관공정, 용접공정 및 확관공정 중의 적어도 하나의 공정에 의해 발생된 인장잔류응력이 존재하는 UOE강관의 외부면에 압축응력을 부여하도록 코팅하는 UOE강관 제조방법.
A pipe forming process for pipe-forming a steel plate, a welding process for welding a pipe, a pipe expanding process for expanding a welded pipe, and a coating process for coating the expanded steel pipe, wherein the coating process includes the entire outer surface of the steel pipe. Or coating to give a compressive stress to the outer surface of the UOE steel pipe in which the tensile residual stress generated by at least one of the pipe forming process, the welding process, and the expanding process is present.
제 1항에 있어서,
상기 코팅에 의해 부여되는 압축응력은 상기 UOE강관의 표면에 형성된 인장잔류응력의 80~120%의 크기를 갖는 UOE 강관 제조방법.
The method of claim 1,
The compressive stress imparted by the coating is UOE steel pipe manufacturing method having a magnitude of 80 ~ 120% of the tensile residual stress formed on the surface of the UOE steel pipe.
제 1항 또는 제 2항에 있어서,
상기 코팅은 플라즈마 스프레이법, 기체상 도금법 및 액적 분사법 중 1종 이상의 방법에 의해 행해지는 UOE강관 제조방법.
3. The method according to claim 1 or 2,
And the coating is performed by at least one of plasma spraying, gas phase plating and droplet spraying.
제 1항 또는 제 2항에 있어서,
상기 코팅시 코팅재료는 Cr+W-C:H, Cr+W-C:H+DLC, CrN+W-C:H+DLC, Cr+W-C:H+Si=DLC, Cr+W-C:H+ta-C로 이루어진 그룹에서 1종 이상인 UOE강관 제조방법.
3. The method according to claim 1 or 2,
In the coating, the coating material is Cr + WC: H, Cr + WC: H + DLC, CrN + WC: H + DLC, Cr + WC: H + Si = DLC, Cr + WC: H + ta-C At least one UOE steel pipe manufacturing method.
제 1항 또는 제 2항에 있어서,
상기 코팅시 코팅 온도는 80~300℃인 UOE강관 제조방법.
3. The method according to claim 1 or 2,
The coating temperature during the coating is 80 ~ 300 ℃ UOE steel pipe manufacturing method.
표면에 코팅층이 형성된 UOE강관으로서,
상기 코팅층은 그 두께가 350~450㎛이고, 코팅 전 강관 내 인장잔류응력이 존재하는 부위에 형성되어 압축응력을 부여하는 UOE강관.
UOE steel pipe with a coating layer formed on the surface,
The coating layer has a thickness of 350 ~ 450㎛, the UOE steel pipe is formed in the portion where the tensile residual stress in the steel pipe before coating to give a compressive stress.
제 6항에 있어서,
상기 코팅된 UOE 강관의 평균 마모속도는 0.5x10-6 ~ 2.0x10-6mm3N-1m-1인 하는 UOE 강관.
The method according to claim 6,
The average wear rate of the coated UOE steel pipe is 0.5x10 -6 to 2.0x10 -6 mm 3 N -1 m -1 UOE steel pipe.
제 6항에 있어서,
상기 코팅에 의해 부여되는 압축응력은 상기 UOE강관의 표면에 형성된 인장잔류응력의 80~120%의 크기를 갖는 UOE 강관.The method according to claim 6,
Compression stress applied by the coating is UOE steel pipe having a magnitude of 80 ~ 120% of the tensile residual stress formed on the surface of the UOE steel pipe.
KR1020110145203A 2011-12-28 2011-12-28 Uoe steel pipe and manufacturing method theheof KR101360689B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110145203A KR101360689B1 (en) 2011-12-28 2011-12-28 Uoe steel pipe and manufacturing method theheof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110145203A KR101360689B1 (en) 2011-12-28 2011-12-28 Uoe steel pipe and manufacturing method theheof

Publications (2)

Publication Number Publication Date
KR20130077924A true KR20130077924A (en) 2013-07-09
KR101360689B1 KR101360689B1 (en) 2014-02-20

Family

ID=48990995

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020110145203A KR101360689B1 (en) 2011-12-28 2011-12-28 Uoe steel pipe and manufacturing method theheof

Country Status (1)

Country Link
KR (1) KR101360689B1 (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09291395A (en) * 1996-04-26 1997-11-11 Toyota Motor Corp Method for controlling residual stress of plating
JP4072009B2 (en) * 2002-07-01 2008-04-02 新日本製鐵株式会社 Manufacturing method of UOE steel pipe with high crushing strength

Also Published As

Publication number Publication date
KR101360689B1 (en) 2014-02-20

Similar Documents

Publication Publication Date Title
Elchalakani Rehabilitation of corroded steel CHS under combined bending and bearing using CFRP
CN101581200A (en) 120 steel grade drill pipe and manufacturing process method thereof
Tayyebi et al. Residual stresses of heat-treated and hot-dip galvanized RHS cold-formed by different methods
CN105351635B (en) Metal ceramic composite pipe and manufacturing process thereof
Khalifeh Stress corrosion cracking behavior of materials
KR101360689B1 (en) Uoe steel pipe and manufacturing method theheof
CA2553344A1 (en) Rockbolts made of high-strength steel pipes and method of manufacturing thereof
Yayla et al. Squeeze-off of polyethylene pressure pipes: Experimental analysis
Fryer et al. The prediction and enhancement of UOE-DSAW collapse resistance for deepwater linepipe
CN104832721A (en) Composite metal pipe material
JP4903635B2 (en) UOE steel pipe with excellent deformability for line pipe
JP4720344B2 (en) Steel pipe, pipeline using the steel pipe
JP6674776B2 (en) Spiral wound gasket
CN105945517B (en) A kind of continuous velocity tubing string and its manufacture method
CN105840919A (en) Continuous pipe resistant to H2S corrosion and manufacturing method thereof
JP6024080B2 (en) Steel welded joint
ATE461764T1 (en) HIGH PRESSURE RESISTANT METAL BELLOWS AND METHOD FOR PRODUCING THE SAME
Shinohara et al. Effect of Tensile Property Distribution on Strain-based Design Application of High Strength UOE Line Pipe
Putić et al. Bending properties of Glass-Polyester Composite Pipes
Le Manchet et al. Corrosion resistance of the lean duplex material UNS S32202 for oil & gas applications
Fan et al. High-Temperature Ductile Damage Behavior and Modeling of X100 Pipeline Steel.
Kong et al. Effects of laser heat treatment on the fracture morphologies of X80 pipeline steel welded joints by stress corrosion
CN206754692U (en) A kind of oil field defeated metallic conduit of oil-collecting collection
Haase et al. Influence of plastic strain on the resistance of heavy-wall SAWL large-diameter pipes to hydrogen induced cracking and sulfide stress cracking
Fazzini et al. Cause and effect assessment after a complex failure of a large ethylene compressor

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20170202

Year of fee payment: 4

FPAY Annual fee payment

Payment date: 20180130

Year of fee payment: 5

FPAY Annual fee payment

Payment date: 20190201

Year of fee payment: 6