Reconstructing the Image of Reflectors at Base-Metal–Weld Interface Using Ultrasonic Antenna Arrays

2021 ◽  
Vol 57 (9) ◽  
pp. 739-752
Author(s):  
A. E. Bazulin ◽  
E. G. Bazulin ◽  
A. Kh. Vopilkin ◽  
D. S. Tikhonov
Keyword(s):  
Base Metal ◽  
Antenna Arrays ◽  
Weld Interface ◽  
Metal Weld

Study on Microstructure and Property of the SHS Welding Joint

2012 ◽  
Vol 590 ◽  
pp. 51-55
Author(s):  
Hui Yang ◽  
Guo Dong Zhang ◽  
Yuan Mei Fei
Keyword(s):  
Base Metal ◽  
Large Scale ◽  
Welded Joint ◽  
Automatic Measurement ◽  
Weld Interface ◽  
Hardness Tester ◽  
Metallurgical Bonding ◽  
Structure Morphology ◽  
Digital Microscope ◽  
Welding Metal

With the self-designed welding powder formula,this experiment employed the SHS reaction to weld the base metal,which was steel Q235 here,then respectively used Olympus large-scale horizontal digital microscope to analyze the structure morphology of the welding seam's different regions,JEOL SEM to point-analyze and line-analyze elements' distribution near the the weld interface and HV-1000 CCD automatic measurement microscopic vickers hardness tester to measure the microhardness of the pure copper's welding seam.The experiment's result shows the hardness of different part of the welded joint varies largely,and that the join of alloy elements can increase the microhardness of the welding metal,and that the welding metal and base metal interdiffuse,grow and mix remarkably near the fusion line,realizing wonderful metallurgical bonding.

Joint Strength and its Improvement of Friction Welded Joint Between Ductile Cast Iron and 5052 Al Alloy

2020 ◽  
Author(s):  
Masaaki Kimura ◽  
Akira Yoneda ◽  
Masahiro Kusaka ◽  
Koichi Kaizu ◽  
Kazuhiro Hayashida ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Base Metal ◽  
Joint Strength ◽  
Welded Joint ◽  
Weld Interface ◽  
Ductile Cast Iron ◽  
Al Alloy ◽  
High Tensile Strength ◽  
Graphite Particles

Abstract To obtain dissimilar joint for easily making multi-material structures, the characteristics of friction welded joint between ductile cast iron (FCD400) and 5052 Al alloy (A5052) was investigated. The relatively high tensile strength of joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa, respectively. However, this joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. Although the weld interface had no intermetallic compound layer, the fractured surface at the A5052 side had some graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particles were reduced from the weld faying surface at the FCD400 side by decarburization treatment. The joint had approximately 96% in the tensile strength of the A5052 base metal and that was fractured between the A5052 side and the weld interface. The joint with high tensile strength as well as the possibility improving the fractured point of that were obtained when those were made with opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.

PWSCC of Bottom Mounted Instrument Nozzles at South Texas Project

2004 ◽  
Author(s):  
Steven Thomas
Keyword(s):  
Base Metal ◽  
Weld Interface ◽  
South Texas ◽  
The Other ◽  
Bottom Surface ◽  
Nondestructive Examination ◽  
Additional Information ◽  
Welding Defects ◽  
Primary Water ◽  
Axial Crack

Primary water stress corrosion cracking (PWSCC) susceptibility of bottom mounted instrument (BMI) nozzles in the South Texas Project reactor vessels was considered low due to the Tcold temperature of the bottom head. During a routine bare metal visual inspection of the Unit 1 bottom head in April 2003 small boric acid deposits were identified at the location where two of the BMI nozzles penetrated the bottom surface of the vessel head. Subsequent nondestructive examination showed three cracks in one of the nozzles two crack in the second nozzle and no cracks in the other 56 nozzles. The nondestructive examinations showed that both leaking nozzles had an axial crack in the nozzle base metal extending from above the J-weld to below the J-weld. One of these cracks extended nearly through-wall while the other did not extend through wall. A boat sample removed from one of the leaking nozzles confirmed the presence of a PWSCC crack in the nozzle base metal and the presence of welding defects at the tube to J-weld interface which could be responsible for initiating the cracks. This paper summarizes the field inspections and laboratory investigations and briefly descries the repair method. See References 1 and 2 for additional information.

Study on Incorporation of New Design Fatigue Curves and a New Environmental Fatigue Correction Factor for PWR Environment Into the JSME Environmental Fatigue Evaluation Method

2020 ◽  
Author(s):  
Seiji Asada ◽  
Shengde Zhang ◽  
Masahiro Takanashi ◽  
Yuichiro Nomura
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Stainless Steels ◽  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Steel Base ◽  
Improved Design ◽  
Fatigue Evaluation ◽  
Cast Stainless Steel ◽  
Metal Weld

Abstract Improved design fatigue curves were developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society (JWES). Working Group on Design Fatigue Curves (WG DFC) in the JSME has studied the validity and the applicability of the improved design fatigue curves developed in the JWES to incorporate into the JSME Environmental Fatigue Evaluation Method. The authors propose a fatigue analysis method using the design fatigue curves developed in the JWES that are applied revised factors to optimize the environmental fatigue analysis. Also, the Japanese pressurized water reactor (PWR) utility group developed equations of environmental fatigue factors (Fen) for austenitic stainless steel base metal, weld metal and cast stainless steel in PWR environment. The WG DFC has investigated the Fen equations and concluded that the Fen equation of austenitic stainless steel base metal is the most conservative among the three equations and close to NUREG/CR-6909 Rev.1 [24]. The authors propose to use the Fen equation for base metal for austenitic stainless steels for all of the base metal, weld metal and cast stainless steel. In addition, the authors have confirmed that the employment of the proposed Fen equation to the proposed design fatigue curves of austenitic stainless steels accurately predicts the existing environmental fatigue test data of austenitic stainless steels, which were used in the development of the current Fen equation of austenitic stainless steels in PWR environments in the JSME Environmental Fatigue Evaluation Method. Therefore, the proposed Fen equation can be applied to environmental fatigue evaluation for austenitic stainless steels.

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