scholarly journals Phased Array Ultrasonic Sound Field Mapping in Cast Austenitic Stainless Steel

2014 ◽  
Author(s):  
Susan Crawford ◽  
Matthew Prowant ◽  
Anthony Cinson ◽  
Michael Larche ◽  
Aaron Diaz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Phased Array ◽  
Sound Field ◽  
Field Mapping ◽  
Ultrasonic Sound

Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components

2014 ◽  
Author(s):  
Susan L. Crawford ◽  
Matthew S. Prowant ◽  
Anthony D. Cinson ◽  
Michael R. Larche ◽  
Aaron A. Diaz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Phased Array ◽  
Flaw Detection ◽  
Sound Field ◽  
Coarse Grained ◽  
Sound Fields ◽  
Fine Grained ◽  
Ultrasonic Sound ◽  
Field Formation

The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased-array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large-grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning, and redirection of these sound fields. The work reported here provides an assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components. Confirmatory research conducted at PNNL consisted of acquiring sound field data from four CASS components containing columnar, equiaxed, and banded grain structures, and a fine-grained wrought stainless steel specimen used for benchmarking. Phased-array probes with center frequencies of 0.5, 0.8, and 1.0 MHz were used for sound field formation, with a pinducer being raster scanned over the end of the specimen face to capture the sound field energy. Data were collected at multiple refracted and skew angles, and imaging performed for analyses. A 6.4-mm (0.25-in.) thick slice of material was removed from the end of the CASS components and the beam mapping repeated. This slicing and mapping sequence was performed three times to produce multiple beam images through the specimens. Grain sizes were also measured at each mapped specimen face and compared to sound field characteristics. The acquired sound field images were characterized in terms of beam redirection from the theoretical position, beam scatter or coherence, and partitioning. A comparison of the fine-grained beam data to the CASS data is made and conclusions are presented.

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.

The Phased Array Ultrasonic Inner Inspection for the Butt Weld on the Head of High-Pressure Vessel

2018 ◽  
Author(s):  
Cunjian Miao ◽  
Qi He ◽  
Xingji Du ◽  
Weican Guo ◽  
Zhangwei Ling ◽  
...  
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Pressure Vessel ◽  
Phased Array ◽  
Small Diameter ◽  
Ultrasonic Field ◽  
Butt Weld ◽  
High Pressure Vessel ◽  
Detecting Method

The layered high-pressure hydrogen vessels are widely used in hydrogen refueling stations. The head of the high-pressure vessel is made of austenitic stainless steel, and has thick walls, a pipe with a small diameter on the top and a butt-weld structure. It’s difficult to detect effectively, using conventional methods in the inspection of the butt weld on the head. To effectively detect the weld joint, a detecting method was investigated using ultrasonic phased array technique from the inner surface of the small-diameter pipe. By axial focusing and circumferential focusing, the ultrasonic field in austenitic stainless steel could satisfy the specific inspection requirement. Some ultrasonic field analysis and defect detection simulations were carried out with CIVA, for artificial defects such as side-drilled holes. Meanwhile, the test specimen and probe were designed and manufactured, and experiments were conducted. Furthermore, the feasibility and rationality of the detecting method and the simulation method were verified, and the detecting process parameters were determined.

Research on Phased Array Ultrasonic Testing for the Girth Weld of 4mm~10mm Austenitic Stainless Steel Pipeline

2018 ◽  
Author(s):  
Lu-yun Zhou ◽  
Ming-hai Fu ◽  
Wei-pu Xu
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Detection System ◽  
Atomic Energy Commission ◽  
Piping System ◽  
Special Equipment ◽  
Steel Pipeline ◽  
Testing Technology

Austenitic stainless steel butt joints are widely used in the pressure piping system, and the quality of welded joints directly affect the safety of pressure special equipment. In this paper, phased array ultrasonic testing technology is used to study the feasibility of 4mm∼10mm wall thickness workpiece. Through the software CIVA (Developed by The French Alternative Energies and Atomic Energy Commission (CEA)) simulat to determine the parameters of the detection system, and it tests the 18 groups of 4mm∼10mm series simulation samples by PAUT (Phased Array Ultrasonic Testing).Through comparison with Radiographic testing, PAUT for the girth weld can be effectively for the 4mm∼10mm Austenitic Stainless Steel Pipeline.

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