Influence of Ultrasonic Incident Angle and Defect Detection Sensitivity by Cast Stainless Steel Structure

2004 ◽  
Author(s):  
Yasuo Kurozumi
Keyword(s):  
Stainless Steel ◽  
Defect Detection ◽  
Incident Angle ◽  
Ultrasonic Inspection ◽  
Steel Structure ◽  
Ultrasonic Waves ◽  
Detection Sensitivity ◽  
Pressurized Water ◽  
Discrimination Capability ◽  
Cast Stainless Steel

It is well known that ultrasonic waves are affected strongly by macro-structures in cast stainless steel, as in the primary pipe or other components in pressurized water reactors (PWRs). In this work, ultrasonic refractive angles and defect detection sensitivities are investigated at different incident angles to cast stainless steel. The aims of the investigation are to clarify the transmission of ultrasonic waves in cast stainless steel and to contribute to the transducer design. The results are that ultrasonic refractive angles in cast stainless steel shift towards the 45-degree direction with respect to the direction of dendritic structures by 11.8 degrees at the maximum and that the sensitivity of transducer for inner surface breaking cracks increases with decreasing incident angle. However, in an ultrasonic inspection of actual welds at smaller incident angles, a trade-off occurs between increased defect detection sensitivity and decreased defect discrimination capability due to intense false signals produced by non-defective features.

Research on Ultrasonic Inspection of Cast Austenitic Stainless Steel Piping

2012 ◽  
Author(s):  
Kazunobu Sakamoto ◽  
Takashi Furukawa ◽  
Ichiro Komura ◽  
Yoshinori Kamiyama ◽  
Tsuyoshi Mihara
Keyword(s):  
Stainless Steel ◽  
Wave Propagation ◽  
Austenitic Stainless Steel ◽  
Ultrasonic Wave ◽  
Research Program ◽  
Ultrasonic Inspection ◽  
Piping System ◽  
Pressurized Water ◽  
Ultrasonic Wave Propagation ◽  
Steel Piping

Japan Nuclear Energy Safety Organization (JNES) has been carrying out the research program entitled “Nondestructive Inspection Technologies for the Cast Stainless Steel Piping” since 2009FY to comprehend the unique ultrasonic wave propagation in the Cast Austenitic Stainless Steel (CASS) and to confirm detection and sizing capability for cracks in the material by currently available ultrasonic testing techniques. The research is also intended to provide inspection staff with the fundamental information of ultrasonic wave propagation in CASS, for educational purpose. In this research program, specimens whose material, size, dimension and welding method are identical to the main coolant piping system in Japanese pressurized water reactors (PWRs) are examined. Results from the study on the capability for inspection of CASS and the unique wave propagation phenomena such as beam skewing are discussed in this paper.

Tensile Tests for Cast Stainless Steel: Evolution of the RCC-M Code

2018 ◽  
Author(s):  
Arnaud Blouin ◽  
Mathieu Couvrat ◽  
Félix Latourte ◽  
Julian Soulacroix
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Tensile Tests ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Different Diameters ◽  
Cast Stainless Steel ◽  
Acceptance Tests ◽  
Do So

In the framework of a pressurized water reactor primary loop replacement, elbows of different types were produced in cast austenitic stainless steel grade Z3CN 20-09 M. For that type of component, acceptance tests to check the sufficient mechanical properties include room and hot temperature tensile tests, following the RCC-M CMS – 1040 and EN 10002 specifications. A large test campaign on standard 10mm diameter specimens was performed and exhibited a high scattering in yield stress and ultimate tensile strength values. As a consequence, some acceptance tensile tests failed to meet the required minimal values, especially the ultimate tensile strength. Optical and electronic microscopy revealed that the low values were due to the presence of very large grain compared to the specimen gage diameter. However, tensile tests strongly rely on the hypothesis that the specimen gage part can be considered as a representative volume element containing a number of grains large enough so that their variation in size and orientation gives a homogeneous response. To confirm the origin of the scattering, a huge experimental tensile test campaign with specimens of different diameters was conducted. In parallel, FE calculations were also performed. From all those results, it was concluded that it was necessary to improve the RCC-M code for that type of test for cast stainless steel: to do so, a modification sheet was sent and is being investigated by AFCEN.

Ultrasonic multi-view total focusing method for weld defect detection on small-diameter austenitic stainless steel tubes

2019 ◽  
Vol 61 (11) ◽  
pp. 649-655
Author(s):  
Wu Bin ◽  
Yang Jing ◽  
Jiao Jingpin ◽  
He Cunfu ◽  
Qi Gaojun
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Defect Detection ◽  
Small Diameter ◽  
Austenitic Stainless Steels ◽  
Ultrasonic Waves ◽  
Imaging Method ◽  
Steel Pipes ◽  
Weld Defect ◽  
Wave Modes

Austenitic stainless steels are widely used in the key components of major equipment and the welds can be the weakest parts of equipment made with these materials. Ultrasonic waves propagate in austenitic stainless steel welds with multiple paths and modes. This study employed a multi-view total focusing method using an ultrasonic phased array for defect detection in the welds of small-diameter austenitic stainless steel pipes. The detection capability of four different direct wave modes and eight different half-skip wave modes for typical defects were compared and analysed through numerical simulation. A fusion imaging method was developed using the preferred direct and half-skip wave modes. The process was further verified with a weld defect detection experiment carried out on small-diameter austenitic stainless steel pipes. The results show that the multi-view total focusing method can efficiently detect the defects in the welds of small-diameter tubes. Compared with the single-mode imaging method, the fusion total focusing imaging approach can not only improve the signal-to-noise ratio but can also reduce the number of image artefacts.

Defect detection and signal processing for cast stainless steel

1988 ◽  
Vol 35 (1-4) ◽  
pp. 57-72
Author(s):  
R. Shankar ◽  
G. Selby ◽  
P. Jeong
Keyword(s):  
Stainless Steel ◽  
Signal Processing ◽  
Defect Detection ◽  
Cast Stainless Steel

Evaluation of Filler Metal 52M (ERNiCrFe-7A) Hot Cracking When Welding on Cast Austenitic Stainless Steel Base Materials

2011 ◽  
Author(s):  
Steven L. McCracken ◽  
Richard E. Smith
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Alloy Steel ◽  
Filler Metal ◽  
Hot Cracking ◽  
Low Alloy Steel ◽  
Pressurized Water ◽  
Centrifugally Cast ◽  
Dissimilar Metal ◽  
Cast Stainless Steel

Dissimilar metal welds of filler metal 182 (ENiCrFe-3) in the primary loop of pressurized water reactor (PWR) nuclear plants are susceptible to primary water stress corrosion cracking (PWSCC) after decades of service. Repair or mitigation has been routinely accomplished by installing a structural weld overlay (SWOL) on the filler metal 182 weld joint with the more PWSCC resistant filler metal 52M (ERNiCrFe-7A). The typical dissimilar metal joint consists of a low alloy steel vessel nozzle welded to an austenitic stainless steel safe end. The SWOL extends from the low alloy steel nozzle over the safe end and most often onto the adjoining wrought or cast stainless steel pipe. Field experience shows that filler metal 52M is susceptible to hot cracking when welding on certain heats of centrifugally cast stainless steel piping. This report evaluates 52M hot cracking when welding on CASS piping and provides the likely cause and mechanism for the cracking. The synergistic influence of silicon (Si) and sulfur (S) elements on the weld bead shape and dilution that leads to hot cracking is investigated. In addition, studies on the influence and use of the gas tungsten arc welding (GTAW) power ratio parameter for 52M overlays are presented.

"Escherichia coli-milk" Biofilm Removal from Stainless Steel Surfaces: Synergism between Ultrasonic Waves and Enzymes

Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Nadia Oulahal- Lagsir ◽  
Adele Martial- Gros ◽  
Marc Bonneauc ◽  
Loic Bluma
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Ultrasonic Waves ◽  
Biofilm Removal ◽  
Steel Surfaces

" Escherichia coli -milk" Biofilm Removal from Stainless Steel Surfaces: Synergism between Ultrasonic Waves and Enzymes

Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
NADIA OULAHAL-LAGSIR ◽  
ADELE MARTIAL-GROS ◽  
MARC BONNEAU ◽  
LOIC BLUM
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Ultrasonic Waves ◽  
Biofilm Removal ◽  
Steel Surfaces

Ultrasonic Inspection of Austenitic Stainless Steel Weldments—Our Experiences

1983 ◽  
Vol 15 (3) ◽  
pp. 91
Author(s):  
V. C. Padaki ◽  
P. Barat ◽  
Baldev Raj ◽  
D. K. Bhattacharya
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultrasonic Inspection

scholarly journals Through-Thickness Microstructure Characterization in a Centrifugally Cast Austenitic Stainless Steel Nuclear Reactor Primary Loop Pipe Using Time-of-Flight Neutron Diffraction

2021 ◽  
Vol 5 (2) ◽  
pp. 12
Author(s):  
Matthew M. Schmitt ◽  
Daniel J. Savage ◽  
James J. Wall ◽  
John D. Yeager ◽  
Chanho Lee ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Neutron Diffraction ◽  
Time Of Flight ◽  
Radial Distance ◽  
Ultrasonic Waves ◽  
Science Center ◽  
Los Alamos ◽  
Inspection Method ◽  
Centrifugally Cast

The US code of Federal Regulations mandates regular inspection of centrifugally cast austenitic stainless steel pipe, commonly used in primary cooling loops in light-water nuclear power plants. These pipes typically have a wall thickness of ~8 cm. Unfortunately, inspection using conventional ultrasonic techniques is not reliable as the microstructure strongly attenuates ultrasonic waves. Work is ongoing to simulate the behavior of acoustic waves in this microstructure and ultimately develop an acoustic inspection method for reactor inspections. In order to account for elastic anisotropy in the material, the texture in the steel was measured as a function of radial distance though the pipe wall. Experiments were conducted on two 10 × 12.7 × 80 mm radial sections of a cast pipe using neutron diffraction scans of 2 mm slices using the HIPPO time-of-flight neutron diffractometer at the Los Alamos Neutron Science Center (LANSCE, Los Alamos, NM, USA). Strong textures dominated by a small number of austenite grains with their (100) direction aligned in the radial direction of the pipe were observed. ODF analysis indicated that up to 70% of the probed volume was occupied by just three single-grain orientations, consistent with grain sizes of almost 1 cm. Texture and phase fraction of both ferrite and austenite phases were measured along the length of the samples. These results will inform the development of a more robust diagnostic tool for regular inspection of this material.

Sign in / Sign up

Export Citation Format

Share Document