Ultrasonic Phased Array Evaluations of Implanted and In-Situ Grown Flaws in Cast Austenitic Stainless Steel Pressurizer Surge Line Piping

2011 ◽  
Author(s):  
Susan L. Crawford ◽  
Anthony D. Cinson ◽  
Traci L. Moran ◽  
Matthew S. Prowant ◽  
Aaron A. Diaz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Phased Array ◽  
Fatigue Cracks ◽  
Base Material ◽  
Pacific Northwest National Laboratory ◽  
Asme Code ◽  
Ultrasonic Phased Array ◽  
Surge Line

A set of circumferentially oriented thermal fatigue cracks (TFCs) were implanted into three cast austenitic stainless steel (CASS) pressurizer (PZR) surge-line specimen welds (pipe-to-elbow configuration) that were salvaged from a U.S. commercial nuclear power plant that had not been operated. Thus, these welds were fabricated using vintage CASS materials that were formed in the 1970s. Additionally, in-situ grown TFCs were placed in the adjacent CASS base material of one of these specimens. Ultrasonic phased-array responses from both types of flaws (implanted and in-situ grown) were analyzed for detection and characterization based on sizing and signal-to-noise determination. Multiple probes were employed covering the 0.8 to 2.0 MHz frequency range. To further validate the Pacific Northwest National Laboratory (PNNL) findings, an independent in-service inspection (ISI) supplier evaluated the flaws with their American Society of Mechanical Engineers (ASME) Code, Section XI, Appendix VIII-qualified procedure. The results obtained by PNNL personnel compared favorably to the ISI supplier results. All examined flaws were detected and sized within the ASME Code-allowable limits.

An Ultrasonic Phased Array Evaluation of Cast Austenitic Stainless Steel Pressurizer Surge Line Piping Welds

2010 ◽  
Author(s):  
Aaron A. Diaz ◽  
Anthony D. Cinson ◽  
Susan L. Crawford ◽  
Traci L. Moran ◽  
Michael T. Anderson
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Fatigue Cracks ◽  
Ultrasonic Beam ◽  
Custom Made ◽  
Ultrasonic Phased Array ◽  
Surge Line ◽  
Thermal Fatigue Cracks

A set of circumferentially oriented thermal fatigue cracks (TFCs) were implanted into three cast austenitic stainless steel (CASS) pressurizer (PZR) surge-line specimens (pipe-to-elbow welds) that were fabricated using vintage CASS materials formed in the 1970s, and flaw responses from these cracks were used to evaluate detection and sizing performance of the phased-array (PA) ultrasonic testing (UT) methods applied. Four different custom-made PA probes were employed in this study, operating nominally at 800 kHz, 1.0 MHz, 1.5 MHz, and 2.0 MHz center frequencies. The CASS PZR surge-line specimens were polished and chemically etched to bring out the microstructures of both pipe and elbow segments. Additional studies were conducted and documented to address baseline CASS material noise and observe possible ultrasonic beam redirection phenomena.

Capabilities of Ultrasonic Phased Arrays for Far-Side Examinations of Austenitic Stainless Steel Piping Welds

2006 ◽  
Author(s):  
Michael T. Anderson ◽  
Stephen E. Cumblidge ◽  
Steven R. Doctor
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Phased Array ◽  
Fatigue Cracks ◽  
Welding Parameters ◽  
Circumferential Welds ◽  
Array Technology ◽  
Asme Code ◽  
Ultrasonic Techniques ◽  
Performance Demonstration

A study was conducted to assess the ability of advanced ultrasonic techniques to detect and accurately determine the size of flaws from the far-side of wrought austenitic piping welds. Far-side inspections of nuclear system austenitic piping welds are currently performed on a “best effort” basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements for near side inspection. For this study, four circumferential welds in 610mm (24inch) diameter, 36mm (1.42inch) thick ASTM A-358, Grade 304 vintage austenitic stainless steel pipe were examined. The welds were fabricated with varied welding parameters; both horizontal and vertical pipe orientations were used, with air and water backing, to simulate field welding conditions. A series of saw cuts, electro-discharge machined (EDM) notches, and implanted fatigue cracks were placed into the heat affected zones of the welds. The saw cuts and notches ranged in depth from 7.5% to 28.4% through-wall. The implanted cracks ranged in depth from 5% through-wall to 64% through-wall. The welds were examined with phased array technology at 2.0 MHz, and compared to conventional ultrasonic techniques as a baseline. The examinations showed that phased-array methods were able to detect and accurately length-size, but not depth size, the notches and flaws through the welds. The ultrasonic results were insensitive to the different welding techniques used in each weld.

Low Frequency Phased Array Application for Crack Detection in Cast Austenitic Piping

2006 ◽  
Author(s):  
Michael T. Anderson ◽  
Stephen E. Cumblidge ◽  
Steven R. Doctor
Keyword(s):  
Stainless Steel ◽  
Crack Detection ◽  
Phased Array ◽  
Fatigue Cracks ◽  
Low Frequency ◽  
Pacific Northwest National Laboratory ◽  
The United States ◽  
Coarse Grained ◽  
Inspection Method ◽  
Centrifugally Cast

As part of a multi-year program funded by the United States Nuclear Regulatory Commission (US NRC) to address nondestructive examination (NDE) reliability of inservice inspection (ISI) programs, studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing novel NDE approaches for the inspection of coarse-grained, cast austenitic stainless steel reactor components. The primary objective of this work is to provide information to the US NRC on the utility, effectiveness and reliability of ultrasonic testing (UT) as related to the ISI of primary piping components in US commercial nuclear power plants. This paper describes progress, recent developments and results from an assessment of a portion of the work relating to the ultrasonic low frequency phased array inspection technique. Westinghouse Owner’s Group (WOG) cast stainless steel pipe segments with thermal and mechanical fatigue cracks, PNNL samples containing thermal fatigue cracks and several blank vintage specimens having very coarse grains that are representative of early centrifugally cast piping installed in PWRs, were used for assessing the inspection method. The phased array approach was implemented using an R/D Tech Tomoscan III system operating at 1.0 MHz and 500 kHz, providing composite volumetric images of the samples. Several dual, transmit-receive, custom designed low-frequency arrays were employed in laboratory trials. Results from laboratory studies for assessing detection and localization are discussed.

Sign in / Sign up

Export Citation Format

Share Document