Effective Use of Weld Metal Yield Strength for HY-Steels

1983 ◽  
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Metal Yield ◽  
Effective Use

EPRG Tier 2 Guidelines for the Assessment of Defects in Transmission Pipeline Girth Welds

2010 ◽  
Author(s):  
Rudi Denys ◽  
Robert Bob Andrews ◽  
Mures Zarea ◽  
Gerhard Knauf
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Pipe Material ◽  
Tier 2 ◽  
Planar Defects ◽  
Transmission Pipeline ◽  
Metal Yield ◽  
Girth Welds

This paper presents the proposed revisions of the EPRG guidelines for the assessment of defects in transmission pipeline girth welds. The revisions cover Tier 2 of the guidelines, in particular (a) the extension of the guidelines to include Grade L555 (X80) material, (b) the assessment of surface-breaking defects with heights up to 5mm and (c) the assessment of multiple co-planar defects. Since the welds should be, at least, matching the pipe material in yield strength, the paper also defines the required levels of weld metal yield strength for the safe application of the guidelines.

Welding of Internally Clad X65 Pipes With Precipitation Strengthened Ni-Based Filler Metals

2017 ◽  
Author(s):  
Graciela C. Penso ◽  
Boian T. Alexandrov
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Parameter Optimization ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Welding Parameter ◽  
Cold Metal Transfer ◽  
Alloy 625 ◽  
Metal Yield ◽  
Cold Metal

X65 steel pipes internally clad with Alloy 625 used in subsea oil extraction are normally welded together with Alloy 625 filler metal. For pipe reeling applications, DNV-OS-F101 requires pipe girth welds to overmatch base metal yield strength with 100 MPa. Since Alloy 625 filler metal does not meet this requirement, Ni-base super alloys 718 and 282 were considered as potential welding consumables for reeling applications. The solidification behavior in weld metal of these alloys diluted with Alloy 625 pipe ID cladding was evaluated using thermodynamic simulations. The response to precipitation hardening by multiple reheat cycles was studied by producing multilayer buildups with cold metal transfer (CMT) and pulsed gas metal arc welding (GMAWp) processes. Weld buildup of Alloy 718 exhibited insufficient hardening response and yield strength, while Alloy 282 met the DNV overmatch requirement. Successful narrow groove welding of X65 pipes with Alloy 282 was performed using CMT process. Welding parameter optimization allowed resolving centerline solidification cracking and lack of fusion defects. The weld metal yield strength was lower than in the multipass buildup, which was attributed to lower number of reheats in groove welding. Meeting the overmatch requirement for yield strength in Alloy 282 groove welds requires further parameter optimization.

Semi-Automatic Gas-Less Process for Girth Welding X-80 Line Pipe

2006 ◽  
Author(s):  
Badri K. Narayanan ◽  
Patrick Soltis ◽  
Marie Quintana
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Slag System ◽  
High Strength ◽  
Automatic Process ◽  
Line Pipe ◽  
High Toughness ◽  
New Process ◽  
Girth Welding ◽  
Acidic Components

A new process (M2M™) to girth weld API Grade X-80 line pipe with a gas-less technology is presented. This process combines innovations in controlling arc length and energy input with microstructure control of the weld metal deposited to achieve high strength (over matching 550 MPa yield strength) and Charpy V-Notch toughness of over 60 Joules at −20°C. This paper will concentrate on the metallurgical aspects of the weld metal and the systematic steps taken to achieve high strength weld metal without sacrificing toughness. The development of an appropriate slag system to achieve the best possible microstructure for high toughness weld metal is discussed. The indirect effects of the slag system on the weld metal composition, which in turn affects the microstructure and physical properties, are detailed. In order to achieve sound weld metal without gas protection using a semi-automatic process, a basic slag system with minimal acidic components is used to improve the cleanliness of the weld metal without sacrificing weldability. In addition, a complex combination of micro-alloying elements is used to achieve the optimum precipitation sequence of nitrides that is critical for high toughness. The final part of this paper gives details about the robustness of this process to weld high strength pipe. The results show that this is a practical and unique solution for girth welding of X-80 pipe to achieve acceptable toughness and over a 15% overmatch in yield strength of X-80 pipe without sacrificing productivity.

scholarly journals Analisis pengaruh variasi elektroda las e6013 dan e7018 terhadap kekuatan tarik dan kekerasan pada bahan baja ss 400

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
M. Abdus Shomad ◽  
M. Shahar Mushfi
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Weld Metal ◽  
Raw Materials ◽  
Parent Metal ◽  
Reverse Polarity ◽  
Metal Part ◽  
Electrode Holder ◽  
Hardness Level ◽  
Negative Pole

Development of technology in the field of construction is increasingly advanced today, will not be separated from technology or welding techniques because it has a very important role in engineering and metal repairs.This study aims to determine the effect of electrode to tensile strength and hardness of SMAW welding on SS 400 steel. The material is given welding treatment with electrode variation E6013 and E7018 diameter of 3.2 mm by using SMAW DC reverse polarity ie the electrode holder is connected to positive pole and the parent metal is connected With a negative pole. The type of camp used is V. The highest tensile strength occurred in the specimens of raw materials that amounted to 432.49 MPa which increased by 10.41 MPa from group E7018. The highest yield strength occurred in the raw materials specimens of 308.53 MPa which had an increase of 9.31 MPa from the E7018 electrode variation group. The highest hardness level occurs in the weld metal part of E7018 electrode variation group that is equal to 189.6 kg /mm2.

Metal-Cored Welding GMAW Consumables Development for Girth Welding of X-100 Pipe

2006 ◽  
Author(s):  
Viadyanath Rajan ◽  
Dennis Hartman
Keyword(s):  
Impact Toughness ◽  
Weld Metal ◽  
Response Surface ◽  
Charpy Impact ◽  
Scale Production ◽  
Cored Wire ◽  
Charpy Impact Toughness ◽  
Metal Composition ◽  
Metal Yield ◽  
Weld Metal Composition

Metal-cored wire electrodes with different compositions were used to make girth weld joints at a heat input of 0.7–0.8 kJ/mm. Design of experiments methodology was used to create a response surface primarily in carbon (C), manganese (Mn) and nickel (Ni) space in steel containing molybdenum (Mo), titanium (Ti), and boron (B) additions. This allowed the modeling of all-weld-metal yield strength, tensile strength and Charpy impact toughness as a function of weld metal composition. Results indicated that weld metal yield and tensile strengths have a linear dependence on the %C, %Mn and %Ni content of the weld. The Charpy impact toughness behavior at −20° C was more complex, initially showing a dependence on %C and %Ni in small scale trials, and subsequently showing a dependence on the %oxygen (O) and %Mn content in full scale production trials. These results can be combined for graphical optimization of the response surface to identify regions in weld metal composition that contain the desired weld metal yield, tensile and Charpy impact toughness for design of metal-cored wire electrodes for the welding of X-100 pipe. These results and their implications for design of girth welds in X-100 pipe are presented in this study.

scholarly journals Effect of Post-Weld Heat Treatment on the Fatigue Behavior of Medium-Strength Carbon Steel Weldments

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1700
Author(s):  
Byeong-Choon Goo
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
Weld Metal ◽  
Base Material ◽  
Charpy Impact ◽  
Parent Material ◽  
Bogie Frame ◽  
Absorption Energy ◽  
Heat Treated ◽  
Impact Absorption

Railway vehicle makers manufacture the bogie frame by welding medium-strength carbon steel sheets. It has been a long-standing practice to perform post-weld heat treatment (PWHT) to remove welding-residual stress, but rail car manufacturers are moving toward producing bogie frames without PWHT. Since securing the fatigue strength of the bogie frame is essential for vehicle operation safety, it is necessary to systematically evaluate the effects of PWHT on hardness, microstructure, mechanical properties, corrosion, fatigue strength, etc. In this study, small-scale welding specimens and full-size components were produced using S355JR used in general structures, automobiles, shipbuilding, railroad vehicles, etc. The effect of PWHT on material properties-the hardness of the base material, heat-affected zone and weld metal, microstructure, shock absorption energy, yield strength, tensile strength, and fatigue were investigated. When the weld specimen was annealed at 590 °C and 800 °C for 1 h, the yield strength and tensile strength of the specimen decreased, but the elongation increased. For specimens not heat-treated, the parent material’s yield strength, the yield strength in HAZ, and the yield strength of the weld metal were 350 MPa, 345 MPa, and 340 MPa. For specimens heat-treated at 590 °C, they were 350 MPa, 345 MPa, and 340 MPa. For specimens heat-treated at 800 °C, they were 350 MPa, 345 MPa, and 340 MPa. Annealing heat treatment of the specimen at 800 °C homogenized the structure of the weldments similar to that of the base material and slightly improved the shock absorption energy. For specimens not heat-treated, the Charpy impact absorption energies at 20 °C of the parent material and weld metal were 291.5 J and 187 J. For specimens heat-treated at 590 °C, they were 276 J and 166 J. For specimens heat-treated at 800 °C, the Charpy impact absorption energy at 20 °C of the parent material was 299 J. PWHT at 590 °C had the effect of slightly improving the fatigue limit of the specimen but lowered the fatigue limit by 10.8% for the component specimen.

Development of Optimized Weld Metal Chemistries for Pipeline Girth Welding of High Strength Line Pipe

2008 ◽  
Author(s):  
Susan R. Fiore ◽  
James A. Gianetto ◽  
Mark G. Hudson ◽  
Suhas Vaze ◽  
Shuchi Khurana ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Yield Strength ◽  
Weld Metal ◽  
High Strength ◽  
Process Variations ◽  
Line Pipe ◽  
Girth Welding ◽  
Dimensional Finite Element ◽  
Initial Work ◽  
Girth Welds

The primary objectives of this program were to provide a better understanding of the factors that control strength and toughness in high strength steel girth welds and to develop optimized welding consumables and welding procedures for high strength pipelines. The initial work on the program involved developing cooling rate models so that optimized weld metal compositions for high-strength pipelines could be developed, ensuring that the ideal balance of strength and ductility, together with tolerance to process variations and resistance to hydrogen cracking is achieved. The model, which was developed under a companion program, uses a two-dimensional finite element approach. Complete details can be found in Reference [1]. The model predicts the cooling rates during various weld passes in narrow groove welding of X80 and X100 pipes. Using this model, along with experimental datasets, a neural network model was developed which has been used to predict weld metal properties for various weld metal compositions. Based on the predictions, eight target compositions were selected and were manufactured by one of the team partners. The results of mechanical property testing showed that it was possible to develop weld metal compositions which exceeded the target yield strength of 820 MPa and also provided excellent toughness (>50J at −60°C). It was also found that the weld metal yield strength measured close to the ID of the pipe was significantly higher than that which was measured closer to the OD of the pipe. Complete mechanical property results, including results for round-bar and strip tensiles, CVN impact toughness, microhardness and more, are presented.

Fracture Toughness and Crack Path Deviations in Laser Welded Joints

2004 ◽  
Author(s):  
Bostjan Bezensek ◽  
John W. Hancock
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Yield Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Crack Path ◽  
Fracture Behaviour ◽  
Misleading Information ◽  
Strength Gradient ◽  
Cleavage Failure

The resistance of laser welded joints to cleavage failure has been examined using fatigue cracked fracture toughness specimens and Charpy tests. The apparent toughness of a range of weld microstructures was determined, the lowest being for a crack located in the weld metal. Sharp cracks deviate into the microstructure with the lowest apparent toughness adjacent to the tip and propagate down the toughness gradient. Charpy tests differ in that the crack consistently propagates into the softer material, and extends down the yield strength gradient adjacent to the tip. Charpy tests can thus give misleading information about the fracture behaviour of mismatched weldments, as crack path deviations may mask a potentially dangerously low toughness weld metal. Recommendations are given on supplementing Charpy weld characterisation with the fracture mechanics tests to ensure conservatism in mismatched weldments.

Ultra-Low Hydrogen Consumables for Welding of High Strength Steels With 690–750 MPa-Yield Strength

2006 ◽  
Author(s):  
Stephen Liu ◽  
Craig Clasper ◽  
Keith Moline ◽  
Joe Scott
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Oxygen Potential ◽  
Mechanical Performance ◽  
Hydrogen Reduction ◽  
High Strength Steels ◽  
High Strength ◽  
Testing Temperature ◽  
Hydrogen Trapping ◽  
Welding Consumable

Two fundamental concepts in welding consumable development were explored in this research. The first concept dealt with the introduction of yttrium-containing oxides into the weld metal for microstructural control and hydrogen trapping. The second concept suggested the use of fluoride species to displace hydrogen from the arc. Combining yttrium and fluorides into one single flux-cored consumable to capture the benefit of hydrogen reduction from both ingredients, however, proved to be difficult. The oxygen potential controlled by yttrium clashed with the fluorine potential controlled by KF. Several iterations led to the successful reconciliation of the oxygen potential and fluorine potential and the development of a new generation of flux-cored consumables with exceptional performance. Using CO2 as shielding gas, these consumables successfully produced welds that contained only 0.6 ml H2/100 g weld metal. With a duplex martensite-acicular ferrite microstructure, a weld metal with yield strength of 99 ksi and tensile strength of 108 ksi was obtained. The weld metal exhibited excellent ductility, 21.8% elongation. Impact toughness exceeded the −60 °F requirement by 88%, reaching values of 76 ft-lb. Charpy-V-notch energy at 0 °F testing temperature measured an outstanding average of 89 ft-lbs. Consumables designed using the two fundamental concepts have demonstrated great capability of producing high strength steel welds that met stringent mechanical performance requirements.

Effect of Strain Ageing on Mechanical Properties of Pipeline Girth Welds

2011 ◽  
Author(s):  
Badri K. Narayanan ◽  
Jon Ogborn
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Base Material ◽  
Dynamic Strain ◽  
Pipe Material ◽  
Cored Wire ◽  
Line Pipe ◽  
Strain Ageing ◽  
Girth Welds ◽  
Welding Processes

Pipeline girth welds for on-shore and off-shore pipelines use a variety of arc welding processes. The trend towards strain based designs for line pipe installation and the effect of coatings for off-shore pipelines have resulted in evaluation and testing of pipe material subjected to strain ageing. However, very little work has been done to systematically study the effect on ferritic weld metal. This work details some initial work done on evaluating the effect of strain ageing on ferritic weld metal deposited with a 1.2 mm diameter flux cored wire under 75% Ar −25% CO2 shielding gas. Pipeline girth welds were welded on API Grade X-70 pipe and tested to get all weld metal tensile and Charpy V-Notch properties. The weld metal strength overmatched the base material by 7–9%. The ductile to brittle transition temperature for the weld metal was −40°C. The effect of strain ageing on weld metal properties was evaluated. All weld metal tensile samples were subjected to varying levels of pre-strain and ageing treatments to evaluate the effect on yield strength and post-yield behavior. An increase in yield strength after straining and ageing as well as the re-appearance of yield point is observed. Increase in pre-strain decreases elongation. Increase in ageing temperature delays the appearance of dynamic strain ageing. The activation energy for the increase in strength after strain ageing has been measured by assuming a diffusion controlled mechanism. Charpy V-Notch samples were taken to generate transition curves of weld metal after strain ageing and compared to the as-welded condition.

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