1、Standard onImperfection TerminologyAPI STANDARD 5T1TENTH EDITION, NOVEMBER 1996REAFFIRMED, AUGUST 2010Standard onImperfection TerminologyUpstream SegmentAPI STANDARD 5T1TENTH EDITION, NOVEMBER 1996REAFFIRMED, AUGUST 2010STD*API/PETRO STD 5TL-ENGL Lb 0732290 05b2228 SPECIAL NOTES API publications nec
2、essarily address problems of a general nature. With respect to par- ticular circumstances, local, state, and federal laws and regulations should be reviewed. API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and
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7、atalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005. This document was produced under API standardization procedures that ensure appro- priate notification and participation in the developmental process and is desig
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10、en, sound engineer- ing and operating practices. These standards are not intended to obviate the need for apply- ing sound engineering judgment regarding when and where these standards should be utilized. The formulation and publication of API standards is not intended in any way to inhibit anyone f
11、rom using any other practices. Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such prod- ucts
12、 do in fact conform to the applicable API standard. All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mchanical, photocopying, recording or Otherwise, without prior written permission from the publisher: Contact the Pu
13、blishel; APi Publishing Services, 1220 L Street, N. W, Washington, D. C. 20005. Copyright O 1996 American Petroleum Institute STD.API/PETRO STD 5TL-ENGL 1776 0732270 05b2227 b24 m FOREWORD The bar notations identify parts of this standard that have been changed from the previous MI edition. This sta
14、ndard is under the jurisdiction of the API Committee on Standardization of Tubu- lar Goods and includes items approved by letter ballot through 1994. This standard shall become effective on the date printed on the cover but may be used voluntarily from the date of distribution. API publications may
15、be used by anyone desiring to do so. Every effort has been made by the institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this pub- lication and hereby expressly disclaims any liabi
16、lity or responsibility for loss or damage re- sulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict. Suggested revisions are invited and should be submitted to the director of the Explora- tion and Production Department, Ame
17、rican Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. . 111 STD-APIIPETRO STD STL-ENGL 199b 0732290 05b2230 34b W CONTENTS Page 1 SCOPE . 1 2 REFERENCES 2 3 DEFINITIONS 2 3.1 English Terms . 3 3.1 French Translation of English Terms . 5 3.1 German Translation of English Terms 8 3.1
18、 Italian Translation of English Terms 12 3.1 Japanese Translation of English Terms 16 3.1 Spanish Translation of English Terms 20 Figures 1-Arc Burn (Large Diameter Submerged Arc Welded Pipe) . 23 2-Black-Crested Threads . 23 3a-Blister (Sectioned) . 23 3b-Blister (Surface) 24 4a-Chattered Threads .
19、 24 no criteria as to severity are addressed. The word imperfection as used herein refers to metallurgical and other features of steel pipe products, which may or may not be injurious to the use of the product. Definition of injuriousness is outside the scope of this document. Defects are defined in
20、 the respective pipe standards. It should be noted that the definitions are listed in English, French, German, Italian, Japanese, and Spanish. 2 References This recommended practice includes by reference the most recent edition of API Specification 5L, Specification for Line Pipe. 2.1 OTHER REFERENC
21、ES The following publications are under the jurisdiction of the API Committee on Standarization of Tubular Goods and are available from the American Petroleum Institute, Publica- tions and Distribution Section, 1220 L Street, Northwest, Washington, D.C. 20005, (202) 682-8375. API Bu1 5A2 Bu1 5C2 Bu1
22、 5C3 Bu1 5C4 RP 5C1 RP 5L1 RP 5L2 RP 5L3 RP 5L5 RP 5L6 RP 5L7 Bulletin on Thread Compounds Bulletin on Pegormance Properties of Cas- ing and Tubing Bulletin on Formulas and Calculations for Casing, Tubing, Drill Pipe, and Line Pipe Properties Bulletin on Round Thread Casing Joint Strength with Combi
23、ned Internal Pressure and Bending Recommended Practice for Care and Use of Casing and Tubing Recommended Practice for Railroad Trans- portation of Line Pipe Recommended Practice for Internal Coating of Line Pipe for Gas Transmission Services. Recommended Practice for Conducting Drop-Weight Tear Test
24、s on Line Pipe. Recommended Practice for Marine Trans- portation of Line Pipe Recommended Practice for Transportation of Line Pipe on Inland Waterways, First Edi- tion, March, i979 Recommended Practices for Unprimed lnter- na1 Fusion Bonded Epoxy Coating of Line Pipe Std 5B Specification for Threadi
25、ng, Gauging, and Thread Inspection of Casing, Tubing, and Line Pipe Threads Specification for Casing and Tubing Specification for Drill Pipe Specjcation for Line Pipe Spec 5CT Spec 5D Spec 5L 3 Definitions 3.1 DEFINITIONS OF IMPERFECTIONS AND DEFECTS OCCURRING IN STEEL PIPE IN LOCATIONS OTHER THAN T
26、HE WELD 3.1.1 arc burns: Localized points of surface melting caused by arcing between electrode or ground and pipe sur- face (Figure 1). 3.1.2 blister: A raised spot on the surface of pipe caused by expansion of gas in a cavity within the pipe wall (Figures 3a and 3b). 3.1.3 crack: A stress-induced
27、separation of the metal which, without any other influence, is insufficient in extent to cause complete rupture of the material. Quench cracks in steel result from stresses produced during the austenite-to martensite transformation, which is accompanied by an in- crease in volume (Figure 6). 3.1.4 d
28、ent: A local change in surface contour caused by mechanical impact, but not accompanied by loss of metal (Figure 8). 3.1.5 eccentricity: A condition of pipe in which the O.D. and I.D. axes are not coincident, resulting in wall thick- ness variation around the circumference at a given section plane (
29、Figure 10). 3.1.6 gouge: Elongated grooves or cavities caused by mechanical removal of metal (Figure 17). 3.1.7 An area in the pipe with a hardness level considerably higher than that of the surrounding metal, usually due to localized quenching (Figure 18). 3.1.8 inclusion: Foreign material or non-m
30、etallic particles entrapped within the metal during solidification (Figure 43). 3.1.9 lamination: An internal metal separation creating layers generally parallel to the surface (Figure 27). 3.1.10 lap: Fold of metal which has been rolled or otherwise worked against the surface of rolled metal, but h
31、as not fused into sound metal (Figure 28). 3.1.1 1 pit: A depression resulting from the removal of hard spot: 1 STD-API/PETRO STD 5TL-ENGL L79b 0732290 05b2233 055 API STANDARD 5T1 2 foreign material rolled into the surface during manufacture (Figure 33). 3.1.12 plug scores: Internal longitudinal gr
32、ooves oc- curring in seamless pipe, usually caused by hard pieces of metal adhering to the high-mill plug (Figure 35). 3.1.13 roll mark: A term applied to surface imperfec- tions caused by improper roll alignment or roll surface dam- age. Such imperfections may be periodic or continuous (Figure 37).
33、 3.1.14 rolled-in slugs: A foreign metallic body rolled into the metal surface, usually not fused (Figure 38). 3.1.15 scab: An imperfection in the form of a shell or veneer, generally attached to the surface by sound metal. It usually has its origin in an ingot defect (Figure 39). 3.1.16 seam: Crevi
34、ce in rolled metal which has been more or less closed by rolling or other work but has not been fused into sound metal (Figure 40). 3.1.17 sliver: An extremely thin elongated piece of metal that has been rolled into the surface of the parent metal to which it is attached usually by only one end (Fig
35、ure 44). 3.1.18 stretch mill indentation: Localized thinning of the pipe body wall - usually located on the inside surface (Figures 47a and 47b). 3.1.19 upset underfill: A depression on the outside or inside surface of an upset caused by insufficient flow of metal to completely fill out the upset to
36、 the desired shape (Figure 52). 3.1.20 upset wrinkles: Surface irregularity occurring on pipe upsets in the form of transverse forging laps (Figure 53). 3.2 DEFINITIONS OF IMPERFECTIONS AND DEFECTS OCCURRING IN DOUBLE SUBMERGED ARC WELDS 3.2.1 excessive reinforcement (excessive over- fill): Outside
37、weld beads which extend above the prolonga- tion of the original surface of the pipe (more than X in. for pipe having a thickness of !4 in. and under, and more than 3xs in. for a pipe having a thickness of over % in. (Figure 11). 3.2.2 incomplete fusion: Lack of complete coales- cence of some portio
38、n of the metal in weld joint (Figure 24). 3.2.3 incomplete penetration (lack of penetration): A condition where the weld metal does not continue through the full thickness of the joint (Figure 25). 3.2.4 offset of plate edges: The radial offset of plate edges in the weld seams (Figure 29). 3.2.5 out
39、-of-line weld beads or OFF seam: A con- dition in which the inner andor outer weld beads are suffi- ciently out of radial alignment with the abutting edges of the joint to cause incomplete penetration (Figure 30). 3.2.6. porosity: Voids in a metal, usually resulting from shrinkage or gas entrapment
40、occurring during solidification of a casting or weldment (Figures 36a, 36b, and 36c). 3.2.7 slag inclusions: Nonmetallic solid material en- trapped in the weld deposit or between weld metal and base metal (Figure 43). 3.2.8 under-cut: Under-cutting on submerged-arc- welded pipe is the reduction in t
41、hickness of the pipe wall ad- jacent to the weld where it is fused to the surface of the pipe (Figure 51). 3.2.9 weld area crack: A crack that occurs in the weld deposit, the fusion line, or the heat affected zone. (Crack: A stress-induced separation of the metal which, without any other influence,
42、is insufficient in extent to cause complete rupture of the material (Figures 54a, 54b, 54c and 54d). 3.3 DEFINITIONS OF IMPERFECTIONS AND DEFECTS OCCURRING IN ELECTRIC FLASH-WELDS 3.3.1 hook cracks or upturned fiber imperfections: Metal separations, resulting from imperfections at the edge of the pl
43、ate or skelp, parallel to the surface, which turn toward the I.D. or O.D. pipe surface when the edges are upset during welding (Figure 19). 3.3.2 inadequate flash trim: A condition in which height of weld flash after trimming exceeds the limits set in the API specification to which the pipe was manu
44、factured (Figure 22). 3.3.3 inclusion: Foreign material or non-metallic particles, entrapped within the metal during solidification (Figure 23). 3.3.4 penetrator: A localized spot of incomplete fusion (Figures 3 la and 3 1 b). 3.3.5 weld area crack A crack in the weld line or the weld upset zone (Cr
45、ack: A stress-induced separation of the metal which, without any other influence, is insufficient in extent to cause complete rupture of the material (Figures 54% 54b, 54c and 54d). 3.4 DEFINITIONS OF IMPERFECTIONS AND DEFECTS OCCURRING IN ELECTRIC RESISTANCE WELDS 3.4.1 cold weld: A metallurgically
46、 inexact term gener- ally indicating a lack of adequate weld bonding strength of the abutting edges, due to insufficient heat and/or pressure. A cold weld may or may not have separation in the weld line. STD-APIIPETRO STD 5TL-ENGL 177b 0732270 05b223Li T91 IMPERFECTION TERMINOLOGY 3 Other more defin
47、itive terms should be used whenever possi- ble (Figure 5). 3.4.2 contact marks: Intermittent marks adjacent to the weld line resulting from the electrical contact between the electrodes supplying the welding current and the pipe surface. 3.4.3 excessive trim: Ref. API Specification 5L, Par. 7.8 (Fig
48、ure 12). 3.4.4 hook cracks or upturned fiber imperfections: Metai separations, resulting from imperfections at the edge of the plate or skelp, parallel to the surface, which turn toward the I.D. or O.D. pipe surface when the edges are upset during welding (Figure 19). 3.4.5 inadequate flash trim: A
49、condition in which height of weld flash after trimming exceeds the limits set in the API specification to which the pipe was manufactured (Figure 23). 3.4.6 inclusion: Foreign material or non-metallic parti- cles entrapped within the metal during solidification (Figure 23). 3.4.7 pinhole: A short unwelded area in the weld line extending through the entire pipe thickness so that fluid will leak out through the area very slowly (Figure 32). 3.4.8 stitching: Variation in the properties of the weld occurring at short regular intervals among the weld line due to repetitive variation in w
