scholarly journals Ultrasonic Inspection of a 9% Ni Steel Joint Welded with Ni-based Superalloy 625: Simulation and Experimentation

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 787 ◽  
Author(s):  
João Payão Filho ◽  
Elisa Passos ◽  
Rodrigo Gonzaga ◽  
Ramon Ferreira ◽  
Daniel Santos ◽  
...  
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Phased Array ◽  
Computational Simulation ◽  
Ultrasonic Inspection ◽  
Low Frequency ◽  
Experimental Tests ◽  
Ultrasonic Waves ◽  
Shielded Metal Arc Welding ◽  
Scanning Angle

The ultrasonic inspection of thick-walled welded joint with austenitic weld metal has proven to be a challenge due to its anisotropic microstructure that can promote ultrasonic waves attenuation. This work aimed to optimize the phased array ultrasonic inspection of the thick-walled joint of a 9% Ni steel pipe welded with Ni-based superalloy 625. The development was carried out by CIVA numeric simulation to preview the beam behavior during the inspection of GTAW (Gas Tungsten Arc Welding)/SMAW (Shielded Metal Arc Welding) joint with anisotropic weld metal. To validate the simulation results, experimental tests were performed with a phased array transducer using longitudinal waves on a calibration block withdrawn from the joint. The configuration of low frequency (2.25 MHz), 16 active elements and a scanning angle of 48° ensured the inspection of the entire joint and the computational simulation proved to be essential for the success of the inspection.

scholarly journals The Influence of the Welding Process on the Ultrasonic Inspection of 9%Ni Steel Pipe Circumferential Welded Joints

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 961
Author(s):  
João da Cruz Payão Filho ◽  
Elisa Kimus Dias Passos ◽  
Rodrigo Stohler Gonzaga ◽  
Daniel Drumond Santos ◽  
Vinicius Pereira Maia ◽  
...  
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Ultrasonic Inspection ◽  
Welding Process ◽  
Oil And Gas Industry ◽  
Co2 Injection ◽  
Shielded Metal Arc Welding ◽  
Scanning Angle ◽  
Metal Arc Welding

This work aims to compare the ultrasonic inspection of 9%Ni steel joints welded with the Gas Metal Arc Welding (GMAW) process and Shielded Metal Arc Welding (SMAW) process. These are the two most widely used processes used to weld pipes for CO2 injection units for floating production storage and offloading (FPSO) in the Brazilian oil and gas industry. The SMAW equipment is simple and portable, which is convenient for the FPSO; however, the GMAW process has the advantage of welding with high productivity. In this study we performed a numerical simulation using the software CIVA, 11th version, to analyze the behavior of ultrasonic longitudinal wave beams through GMAW and SMAW dissimilar weld joints. Ultrasonic tests were performed on calibration blocks drawn from both welded joints to evaluate the simulation results. The results are discussed with regard to the microstructure of the weld metal via electron backscatter diffraction (EBSD) analyses. The SMAW process presented better inspection performance than the GMAW process in terms of attenuation and dispersion effects. Although the SMAW had a better outcome, for both processes the configuration of 16 active elements and a scanning angle of 48° resulted in an optimized inspection of the entire joint.

Fracture Mechanics of Conventional and Narrow Groove Pulse Current Gas Metal Arc Welds of HSLA Steel

2012 ◽  
Vol 710 ◽  
pp. 451-456
Author(s):  
Ravi Ranjan Kumar ◽  
P. K. Ghosh
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Tensile Properties ◽  
Arc Welding ◽  
Hsla Steel ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Compact Tension ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Mechanical and fracture properties of 20MnMoNi55 grade high strength low alloy (HSLA) steel welds have been studied. The weld joints were made using Gas Tungsten Arc Welding (GTAW), Shielded Metal Arc Welding (SMAW) and Pulse Gas Metal Arc Welding (P-GMAW) methods on conventional V-groove (V-Groove) and Narrow groove (NG-13). The base metal and weld metal were characterised in terms of their metallurgical, mechanical and fracture toughness properties by following ASTM procedures. The J-Integral fracture test was carried out using compact tension C(T) specimen for base and weld metal. The fracture toughness and tensile properties of welds have been correlated with microstructure. In conventional V-groove welds prepared by P-GMAW shows the improvement in initiation fracture toughness (JIC) as compared to the weld prepared by SMAW. Similar improvements in tensile properties have also been observed. This is attributed to reduction in co-axial dendrite content due to lower heat input during P-GMAW process as compared to SMAW. In the narrow groove P-GMA weld prepared at f value of 0.15 has shown relative improvement of JIC as compared to that of the weld prepared by SMAW process.

Fracture Behaviour of Type 304LN Stainless Steel and Its Welds

2006 ◽  
Author(s):  
J. S. Dubey ◽  
J. K. Chakravartty ◽  
P. K. Singh ◽  
S. Banerjee
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Fracture Behaviour ◽  
Initiation Toughness ◽  
Second Phase ◽  
Shielded Metal Arc Welding ◽  
Width Measurements ◽  
304Ln Stainless Steel

SA312 type 304LN stainless steel material, having closer control over impurities and inclusion content, is the intended piping material in the Advanced Heavy Water Reactors. Deformation, fatigue and fracture behaviour of this material and its weldments have been characterized at ambient temperature and at 558K. The details of the fractographic investigations and stretch zone width measurements are also discussed. The base metals shows high initiation toughness (>500 kJ/m2) and large tearing modulus at ambient and operating temperatures. Shielded Metal Arc Welding (SMAW) weld metal shows much much reduced initiation toughness and tearing resistance in comparison to base metal and Gas Tungsten Arc Welding (GTAW) welds. This is attributed to larger density of second phase inclusions in the SMAW weld metal. SZW measurements give a good alternate estimate of the toughness of the materials. Fatigue crack growth rate in SMAW weld metal was found to be comparable to base metal at higher load ratios.

scholarly journals The Effect of Cast Iron Preheating on the Microstructure of Welding Results by Using Cin-2 Electrodes

Teknomekanik ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 50-55
Author(s):  
Ahmad Sabirin ◽  
Purwantono Purwantono
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Weld Metal ◽  
Arc Welding ◽  
Shielded Metal Arc Welding ◽  
Affected Area ◽  
Weld Joints ◽  
Microstructure Observation ◽  
Metal Arc Welding ◽  
The One

Cast iron is commonly found in engineering tools such as machine frames, vise, lathes, planers, pressing tools, V-belt pulleys and others. Cast iron is a metal which is relatively difficult to weld because it contains more than 0.3% carbon. As a matter of fact, a lot of welding workers still experience failure in welding the cast iron, so they require the proper procedures to perform welding on the cast iron like the heat treatment before the welding. This study was aimed at obtaining the effect of preheating variations on the weld joints in which the process of welding the material used the type of open V seam connection. The specimen used was a cast iron with a thickness of 10 mm and the electrode used was the JIS Z 3252 DFCNiFe electrode. The method applied in this research was the microstructure observation testing toward the welding result by using Shielded Metal Arc Welding (SMAW). Based on the results of the study, it can be concluded that by applying the preheating variation treatment on the cast iron welding, there was a change in the microstructure and it was dominated by pearlite-ferrite in the weld metal area. As a result, the rough graphite that looks like roots became smooth after experiencing the preheating treatment because the ferrite was evenly distributed in the heat affected area. To conclude, the most superior specimen for the cast iron preheating among the four specimens was the one with 425oC temperature.

scholarly journals Development of Low-Frequency Phased Array for Imaging Defects in Concrete Structures

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7012
Author(s):  
Yoshikazu Ohara ◽  
Kosuke Kikuchi ◽  
Toshihiro Tsuji ◽  
Tsuyoshi Mihara
Keyword(s):  
Lead Zirconate Titanate ◽  
Phased Array ◽  
Concrete Structures ◽  
Low Frequency ◽  
Concrete Specimen ◽  
Ultrasonic Waves ◽  
Center Frequency ◽  
Single Element ◽  
Array Transducer ◽  
Crack Type

The nondestructive inspection of concrete structures is indispensable for ensuring the safety and reliability of aging infrastructures. Ultrasonic waves having a frequency of tens of kHz are frequently used to reduce the scattering attenuation due to coarse aggregates. Such low frequencies enable the measurement of the thickness of concrete structures and detection of layer-type defects, such as delamination, whereas it causes a lack of sensitivity to crack-type defects. In this paper, to realize the ultrasonic phased array (PA) imaging of crack-type defects, we fabricated a low-frequency (LF) array transducer with a center frequency of hundreds of kHz. To avoid the crosstalk between piezoelectric elements and dampen the vibration of each element, we adopted soft lead zirconate titanate (soft PZT) with a low mechanical quality factor. Subsequently, we optimized the geometry of each piezoelectric element using a finite element method to generate a short pulse. After validating the design in a fundamental experiment using a single-element transducer, we fabricated a 32-element array transducer with a center frequency of 350 kHz. To show the imaging capability of the LF array transducer, we applied it to a concrete specimen with a delamination. As a result, the PA with the LF array transducer clearly visualized the delamination, which could not be visualized using the PA with a 2.5 MHz array transducer. Furthermore, we applied it to a more challenging defect, a slit, which is sometimes used to simulate crack-type defects. As a result, the PA with the LF array transducer clearly visualized a slit of 1 mm width and 40 mm height in a concrete specimen. Thus, we demonstrated the usefulness of the LF array transducer for inspecting crack-type defects.

scholarly journals Influence of Stick Electrode Coating’s Moisture Content on the Diffusible Hydrogen in Underwater Wet Shielded Metal Arc Welding

2020 ◽  
Vol 20 (4) ◽  
pp. 27-37
Author(s):  
J. Klett ◽  
T. Hassel
Keyword(s):  
Weld Metal ◽  
Hydrogen Content ◽  
Water Depth ◽  
Arc Welding ◽  
Hydrogen Uptake ◽  
Shielded Metal Arc Welding ◽  
Diffusible Hydrogen ◽  
Relative Contribution ◽  
Metal Arc Welding ◽  
Water Depths

AbstractIn shielded metal arc welding, the major factors influencing hydrogen uptake into the weld metal are (i) the hydrogen content of the base metal, (ii) hydrogen input by the welding consumable, and (iii) the hydrogen introduced by the atmosphere surrounding the arc process. In this study, the relative contribution of these factors is investigated and compared to each other for the case of underwater wet shielded metal arc welding. To assess the influence of the stick electrode’s moisture (capillary introduced water during handling operations) on the diffusible hydrogen in wet welded samples, wet and dry electrodes were welded at four different water depths. The moisture was absorbed through the sharpened electrode tip only, to ensure close to service conditions. The results show that the moist stick electrode coatings lead to 22.6% higher average diffusible hydrogen content in the weld metal (0.5 m water depth an average). However, the effect disappears with increasing water depths (no difference in 60 m water depth).

Effects of Welding Positions on Mechanical Properties and Microstructure in Weld Metal of High Strength Steel

2009 ◽  
Vol 83-86 ◽  
pp. 1121-1127 ◽  
Author(s):  
F. Masoumi ◽  
D. Shahriari
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Arc Welding ◽  
High Strength ◽  
Vertical Position ◽  
Shielded Metal Arc Welding ◽  
Tensile Impact ◽  
Metal Arc Welding ◽  
Welding Metal ◽  
Welding Position

In this study the effects of two welding positions included in flat and upward vertical on the mechanical properties and microstructure of high strength weld metal deposited with shielded metal arc welding (SMAW) using an electrode of ASME SFA 5.5-96 E9018B3 type have been investigated. The aim of the present work is to study the effects of these two welding positions for a weld metal alloyed with 1%Mo, 2%Cr, 0.79%Mn, and 0.08% C in the stress relieved condition. For studying mechanical properties Tensile, Impact and hardness experiments have been conducted; meanwhile chemical analysis and microstructure studying have been carried out on specimens. The results show that welding position does not have any significant effect on tensile and hardness of the weld metal but in vertical position welding metal toughness is lower than toughness in flat position in all temperatures. Transition temperature of ductile fracture to brittle fracture is -50 °C for E9018B3 in welding of high strength micro alloyed steels.

Sign in / Sign up

Export Citation Format

Share Document