Sizing Stress Corrosion Cracking in Natural Gas Pipelines Using Phased Array Ultrasound

2002 ◽  
Author(s):  
Jack Spanner ◽  
Greg Selby
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Phased Array ◽  
Corrosion Cracking ◽  
Depth Information ◽  
Natural Gas Pipelines ◽  
Replacement Decisions ◽  
Inspection Systems ◽  
Pass Through ◽  
As Stress

Gas transmission pipelines are inspected periodically by robotic systems that pass through the pipe. These inspection systems typically use electromagnetic nondestructive evaluation (NDE) techniques to detect flaws such as stress corrosion cracking (SCC). The electromagnetic techniques can detect and measure the length of the cracks, but cannot measure through wall depths. In some cases it would be desirable to excavate down to a cracked area of the pipe, inspect it “in the ditch” to determine the depth of the cracking, and use the depth information to support repair/replacement decisions. The objective of the research was to develop a nondestructive inspection technique capable of measuring the depth of stress corrosion cracks from the outside surface of a gas transmission pipe in the field. EPRI participated in the round robin study by using a linear phased array technique. Field removed specimens were provided by the Gas Technology Institute (GTI) containing SCC for depth sizing. In most cases sizing was difficult to accomplish because of the colony of cracks that existed. This presentation discusses the results obtained and comparing them to destructive analysis results.

Validation of EMAT ILI for Management of Stress Corrosion Cracking in Natural Gas Pipelines

2014 ◽  
Author(s):  
Toby Fore ◽  
Stefan Klein ◽  
Chris Yoxall ◽  
Stan Cone
Keyword(s):  
High Resolution ◽  
Natural Gas ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Probability Of Detection ◽  
Gas Pipelines ◽  
Line Pipe ◽  
Natural Gas Pipelines ◽  
Electro Magnetic

Managing the threat of Stress Corrosion Cracking (SCC) in natural gas pipelines continues to be an area of focus for many operating companies with potentially susceptible pipelines. This paper describes the validation process of the high-resolution Electro-Magnetic Acoustical Transducer (EMAT) In-Line Inspection (ILI) technology for detection of SCC prior to scheduled pressure tests of inspected line pipe valve sections. The validation of the EMAT technology covered the application of high-resolution EMAT ILI and determining the Probability Of Detection (POD) and Identification (POI). The ILI verification process is in accordance to a API 1163 Level 3 validation. It is described in detail for 30″ and 36″ pipeline segments. Both segments are known to have an SCC history. Correlation of EMAT ILI calls to manual non-destructive measurements and destructively tested SCC samples lead to a comprehensive understanding of the capabilities of the EMAT technology and the associated process for managing the SCC threat. Based on the data gathered, the dimensional tool tolerances in terms of length and depth are derived.

Effect of Trace Element Erbium on Corrosion Resistance Properties of Al-Zn-Mg-Cu Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 663-667 ◽  
Author(s):  
Xu Dong Wang ◽  
Zuo Ren Nie ◽  
Shuang Ping Lin ◽  
Xue Kuan Su ◽  
Ze Bing Xing
Keyword(s):  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
Corrosion Test ◽  
Optical Microscope ◽  
Corrosion Cracking ◽  
Cracking Resistance ◽  
Cu Alloy ◽  
As Stress

The intergranular corrosion and stress corrosion cracking resistance of Al-Zn-Mg-Cu alloy with trace Er addition were studied by means of such methods as stress corrosion cracking and intergranular corrosion test in GB-T7998-2005 and HB5254-83. The microstructures were observed by optical microscope and scanning electron microscope (SEM). The results show that alloys with trace Er addition have been improved on intergranular corrosion and stress corrosion cracking resistance, but corrosion resistance of alloys can be descending when Er addition exceed 0.4%.

Stress Corrosion and Hydrogen Cracking off 17-7 Stainless Steel

CORROSION ◽  
1966 ◽  
Vol 22 (1) ◽  
pp. 23-27 ◽  
Author(s):  
I. MATSUSHIMA ◽  
D. DEEGAN ◽  
H. H. UHLIG
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Face Centered Cubic ◽  
Hydrogen Cracking ◽  
Pure Phase ◽  
Face Centered ◽  
As Stress ◽  
Mgcl2 Solution

Abstract Whether a stainless steel fails by stress corrosion cracking or by hydrogen cracking depends on its structure. A pure ferritic 18–8, body-centered cubic as quenched, fails by hydrogen cracking when cathodically polarized in dilute sulfuric acid containing arsenic trioxide. However, it is resistant to stress corrosion cracking in MgCl2 solution boiling at 154 C (310 F). A similar composition austenitic 18–8, face-centered cubic as quenched and tested similarly is resistant to hydrogen cracking but fails by stress corrosion cracking. Type 301 austenitic 17–7 stainless steel, which transforms in part to ferrite on cold rolling, is resistant, therefore, to hydrogen cracking as annealed-quenched or slightly cold reduced. It fails within 10–30 minutes when cold reduced more than 20 percent even though it transforms only partially to ferrite. In MgCl2 solution, both the annealed-quenched and the cold-reduced alloy fail, cracking times being prolonged by cathodic polarization, characterizing the failures as stress corrosion cracking. Contrary to reactions observed in pure phase alloys, stainless steels containing mixtures of austenite and ferrite may fail either by hydrogen cracking or by stress corrosion cracking, depending on the environment.

Environmental Effects on the Cracking of Engineering Materials

MRS Bulletin ◽  
1989 ◽  
Vol 14 (8) ◽  
pp. 37-43 ◽  
Author(s):  
David B. Kasul ◽  
Lloyd A. Heldt
Keyword(s):  
Hydrogen Embrittlement ◽  
Liquid Metal ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Environmental Effects ◽  
Nuclear Power ◽  
Corrosion Cracking ◽  
Service Environments ◽  
As Stress ◽  
Environment Stress

A material's susceptibility to cracking may be significantly affected by its chemical environment. Stress corrosion cracking (SCC), liquid metal embrittle-ment (LME), hydrogen embrittlement (HE), and corrosion fatigue are examples of environmental effects which cause ductility or endurance losses through environment-assisted cracking (EAC). Under certain conditions, virtually all commercially important materials are susceptible to one or more of the above embrittlement processes. Cracking may occur intergranularly, transgranularly, or in a mixed mode, depending on conditions. Much is known about the metallurgical and environmental conditions which promote environment-assisted cracking, and prudent control of these is often successful in mitigating or preventing cracking. However, in spite of our understanding of the factors controlling SCC, LME, and HE, the responsible mechanisms remain elusive.This article will (1) review some of the important variables affecting these phenomena, such as stress, stress intensity, material microstructure, strain rate, electrochemical potential and pH, and (2) attempt to relate phenomeno-logical characteristics of environment-induced embrittlement to several mechanisms proposed for environment-assisted cracking, as they are understood today.The problem of stress corrosion cracking is unquestionably the most costly of environmental cracking phenomena, with losses occurring in a wide variety of service environments. Liquid metal embrittlement is of concern in nuclear power and other industries. Hydrogen embrittlement, first recognized as an embrittler of iron in 1873, causes cracking problems in applications ranging from welding to oil drilling. In all, the list of situations in which environment-assisted cracking occurs is long and is likely to grow as materials are increasingly challenged by the severity of their service conditions.

Hot Cracks as Stress Corrosion Cracking Initiation Sites in Laser Welded Corrosion Resistant Alloys

2005 ◽  
pp. 165-182
Author(s):  
K. Stelling ◽  
Th. Böllinghaus ◽  
M. Wolf ◽  
A. Schöler ◽  
A. Burkert ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Corrosion Resistant ◽  
As Stress

AMBRONZE 413

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Electrical Contact ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Tin Bronze

Abstract AMBRONZE 413 is a copper-tin bronze recommended for plater's plates and electrical contact springs. It is relatively immune to stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-201. Producer or source: Anaconda American Brass Company.

NICROFER 5716 HMoW

Alloy Digest ◽  
1985 ◽  
Vol 34 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Crevice Corrosion ◽  
Corrosion Cracking ◽  
Low Carbon ◽  
Nickel Chromium ◽  
Corrosion Pitting

Abstract NICROFER 5716 HMoW is a nickel-chromium-molybdenum alloy with tungsten and extremely low carbon and silicon contents. It has excellent resistance to crevice corrosion, pitting and stress-corrosion cracking. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Ni-324. Producer or source: Vereingte Deutsche Metallwerke AG.

NAS 825

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Nickel Alloy ◽  
Stress Corrosion Cracking ◽  
Chloride Ion ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Corrosion Resistant

Abstract NAS 825 is a corrosion-resistant nickel alloy that has resistance to both oxidizing and reducing environments, and with 42% nickel, the alloy is very resistant to chloride-ion stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-694. Producer or source: Nippon Yakin Kogyo Company Ltd.

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