New FCAW Electrode for Producing Ultra-Clean High-Toughness Welds in X-80 and X-100 Steel

2016 ◽  
Author(s):  
Susan Fiore
Keyword(s):  
Weld Metal ◽  
Calcium Fluoride ◽  
Slag System ◽  
High Strength ◽  
Ease Of Use ◽  
Basic Slag ◽  
Low Oxygen ◽  
Flux Cored Arc Welding ◽  
High Level ◽  
Filler Metals

The challenges associated with the welding of high-strength pipeline steels, such as X-80 and X100, are well established. While there are many filler metals that provide either adequate strength or good impact toughness, it is difficult to find products that provide both. Add to that the need for all-position welding and high deposition rates, and the options become almost non-existent. Several years ago, Hobart® Filler Metals began working on a line of flux-cored arc welding (FCAW) consumables that are unique in the welding industry. The products have a basic slag system, but do not operate like traditional EXXXT-5 electrodes. Traditional T-5 electrodes have a low-melting, fluid slag, which makes welding out-of-position especially difficult. They also have a high level of calcium fluoride, which affects the stability of the arc and causes weld spatter. While the weld metal mechanical properties and crack-resistance are excellent, the welder appeal and ease-of-use tend to be sorely lacking in most EXXXT-5 electrodes. The new approach utilizes aluminum for deoxidation, which has the added benefit of very clean weld deposits. The composition has been carefully optimized with appropriate levels of carbon, silicon, nickel and manganese. Alternative fluorine sources are used in place of calcium fluoride, which results in very good welder appeal and all-positional capabilities, including vertical down. The novel use of aluminum in a gas shielded process results in very low oxygen, nitrogen and sulfur content, providing exceptionally clean, tough weld deposits. Although the new products have been produced over a range of strength levels, the primary emphasis of this paper is on E691T5-GC (E101T5-GC) and E831T5-GC (E121T5-GC) electrodes. Testing shows that tensile strength levels ranging from 700–880 MPa (100–128 ksi) can be achieved, with toughness levels of 120 J at −60°C (90 ft-lbs at −76°F) or better. The highly basic slag, combined with low weld metal hydrogen (less than 4 ml/100 gm), provides excellent resistance to cracking. The product can be used in all positions, including vertically down, making it an especially appealing choice for welding high-strength pipe.

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.

Development of Welding Procedures for X90-Grade Seamless Pipes for Riser Applications

2012 ◽  
Author(s):  
Hiroyuki Nagayama ◽  
Masahiko Hamada ◽  
Mark F. Mruczek ◽  
Mark Vickers ◽  
Nobuyuki Hisamune ◽  
...  
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Mechanical Test ◽  
Welding Process ◽  
High Strength ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
Flux Cored Arc Welding ◽  
Welding Procedure ◽  
Submerged Arc

Ultra-high strength seamless pipes of X90 and X100 grades have been developed for deepwater or ultra-deepwater applications. Girth welding procedure specifications (WPSs) should be developed for the ultra-high strength pipes. However, there is little information for double jointing welding procedure by using submerged arc welding process for high strength line pipes. This paper describes mechanical test results of submerged arc welding (SAW) and gas shielded flux cored arc welding (GSFCAW) trials with various welding consumables procured from commercial markets. Welds were then made with typical welding parameters for riser productions using high strength X90 seamless pipes. The submerged arc weld metal strength could increase by increasing alloy elements in weld metal. The weld metal with CE (IIW) value of 0.74 mass% achieved fully overmatching for the X90 pipe. The weld metal yield strength (0.2% offset) was 694 MPa, and the ultimate tensile strength was 833 MPa. It was also confirmed that the reduction of boron in weld metal can improve low temperature toughness of high strength weld metal. Furthermore, it was confirmed that the HAZ has excellent mechanical properties and toughness for riser applications. In this study GSFCAW procedures were also developed. GSFCAW can be used for joining pipe and connector material for riser production welding. The weld metal with a CE (IIW) value of 0.54 mass% could meet the required strength level for X90-grade pipe as specified in ISO 3183. Cross weld tensile testing showed that fractures were achieved in the base metal. Good Charpy impact properties in weld metal and HAZ were also confirmed.

Effect of Weld Metal Microstructure on Cold Crack Susceptibility of High Strength Weld

2008 ◽  
Vol 580-582 ◽  
pp. 13-16
Author(s):  
Hee Jin Kim ◽  
Jun Seok Seo ◽  
Jae Hak Kim ◽  
Ka Hee Kim ◽  
Jin Hyun Koh ◽  
...  
Keyword(s):  
Weld Metal ◽  
Hydrogen Content ◽  
High Strength ◽  
Cold Cracking ◽  
Diffusible Hydrogen ◽  
Fca Welding ◽  
Flux Cored Arc Welding ◽  
Metal Microstructure ◽  
Multipass Weld ◽  
Crack Susceptibility

Facing the practical difficulties in reducing the diffusible hydrogen content of fluxcontaining welding consumables like flux-cored arc welding (FCAW) wires, the present study investigated the microstructural aspect to improve the hydrogen-induced cold crack (HICC) resistance of multipass weld metal of 600MPa strength. Two FCA welding wires were prepared by controlling the Ni content to give different weld microstructure, but to have similar levels of hardness and diffusible hydrogen content. HICC susceptibility of those two consumables was evaluated by 'G-BOP test' and also by 'multi-pass weld metal cold cracking test'. As a result of this study, it was demonstrated that microstructural modification with decreased proportion of grain boundary ferrite (GF) improved cold crack resistance of weld metal. The detrimental effect of GF against HICC has also been addressed based on the characteristics of weld metal cold cracking.

Effect of Orbital Automatic Welding on the Weld Metal Mechanical Properties in API 5L X65 Natural Gas Transmission Pipe

2000 ◽  
Author(s):  
Jong-hyun Baek ◽  
Young-pyo Kim ◽  
Woo-sik Kim
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Welding Process ◽  
Charpy Impact ◽  
Hardness Test ◽  
Outer Diameter ◽  
Automatic Welding ◽  
Shielded Metal Arc Welding ◽  
Flux Cored Arc Welding ◽  
Filler Metals

API 5L X65 steel pipes with a 17.5mm wall thickness and 762mm in outer diameter were welded using an orbital automatic welding process. Flux Cored Arc Welding (FCAW) and Gas Tungsten Arc Welding (GTAW) consumables were utilized to evaluate automatic the welding process. Manual welds were deposited using GTAW with ER70S-G filler metal for the root pass and Shielded Metal Arc Welding (SMAW) with low hydrogen E9016-G electrode for the remaining passes. Charpy impact test, CTOD (Crack Tip Opening Test) test and micro-hardness test on the weld metal were carried out and the effects of weld metal composition and microstructure on the weld metal toughness were investigated. The filler metals that have superior fracture toughness were E80T1-K2 and E71T-1 of FCAW process and ER80S-G of GTAW process. The filler metals that have proper hardness were E80T1-K2 and E71T-1 of FCAW process.

Research on Lagging Melt Phenomenon and Influencing Factors of Flux Cored Arc Welding

2012 ◽  
Vol 557-559 ◽  
pp. 1326-1329
Author(s):  
Yan Wang
Keyword(s):  
Influencing Factors ◽  
Arc Welding ◽  
Digital Camera ◽  
Metal Droplet ◽  
Slag System ◽  
Protective Atmosphere ◽  
Basic Slag ◽  
Cored Wire ◽  
Flux Cored Arc Welding

Lagging melt phenomenon is the special phenomenon of flux cored arc welding, studying lagging melt phenomenon is very valuable for the design and improvement of flux cored wire. Used digital camera technology, recorded the lagging melt phenomenon of acid、basic and metallic slag systems flux cored arc welding in CO2 protective atmosphere. Analyzed its mechanism and influencing factors of lagging melt phenomenon. The results shows that lagging melt phenomenon under low welding criterion is not obvious in comparison to high welding criterion but still shows lagging melt tendency. Under high welding criterion lagging melt degree increases and metal droplet separated from lagging melt flux core forms separated transfer. Under same welding criterion, lagging melt degree of basic slag system is maximum, acid slag takes the second place and metallic slag system is minimum.

scholarly journals Effect of weld metal composition on impact toughness properties of shielded metal arc welded ultra-high hard armor steel joints

2020 ◽  
Vol 29 (1) ◽  
pp. 186-194
Author(s):  
V. Balaguru ◽  
Visvalingam Balasubramanian ◽  
P. Sivakumar
Keyword(s):  
Impact Toughness ◽  
Weld Metal ◽  
Welded Joints ◽  
Weight Ratio ◽  
High Hardness ◽  
High Strength ◽  
Solidification Mode ◽  
Austenitic Phase ◽  
Ferrite Number ◽  
Steel Joints

AbstractNowadays, ultra-high hard armor (UHA) steels are employed in armor tracked vehicle (ATV) construction because of their high hardness, high strength to weight ratio, and excellent toughness. UHA steels are usually welded using austenitic stainless steel (ASS) welding consumables, to avoid hydrogen-induced cracking (HIC). The use of ASS consumables to weld the above steel was the only available remedy because of higher solubility of hydrogen in the austenitic phase. In this investigation, an attempt was made to investigate the effect of ASS consumables (with different Creq/Nieq ratio) on solidification mode, impact toughness and microstructural characteristics of shielded metal arc (SMA) welded UHA steel joints. The welded joints were characterised based on impact toughness properties, hardness, and microstructural features. As the ferrite number increases with an increase in Creq/Nieq ratio result in different solidification mode (A, FA, F). It is also found that ferrite number of weld metal has appreciable influence on impact toughness and has inversely proportional relationship with impact toughness of the welded joints.

Study of simulated HLW-glass leaching behavior under low oxygen repository condition

2006 ◽  
Vol 932 ◽  
Author(s):  
Zhang Hua ◽  
Luo Shanggeng
Keyword(s):  
Glass Surface ◽  
Diffraction Peak ◽  
Ambient Atmosphere ◽  
Low Oxygen ◽  
Secondary Products ◽  
Leaching Behavior ◽  
Geologic Disposal ◽  
Oxygen Condition ◽  
High Level ◽  
Glass Leaching

ABSTRACTMany countries have recognized vitrification as the suitable solidification method for conditioning high level radioactive waste before they are isolated from biosphere in geologic disposal. This paper studies the leaching behavior of a simulated HLW-glass (90Nd/10) under low oxygen repository condition during 1.5 years. The leaching results showed that the glass was corroded less under low oxygen condition than under ambient atmosphere. XRD analyses showed some little diffraction peak appeared on the leached glass surface at 150°C. At the same time, no diffraction peak appeared on the leached glass surface at 90°C. The secondary products formed on the surface of the leached glass contained mainly Si, Al, Ca and Fe.

Smartphone Adoption on Fruit Marketing Communication: a Traders Perception

2020 ◽  
Vol 19 (2) ◽  
pp. 433-446
Author(s):  
Heri Akhmadi ◽  
Muhammad Fauzan
Keyword(s):  
Descriptive Analysis ◽  
Low Complexity ◽  
Ease Of Use ◽  
Relative Advantage ◽  
Marketing Communication ◽  
Communication Tool ◽  
Marketing Activities ◽  
High Level ◽  
Media Applications ◽  
Yogyakarta City

Smartphone is one of the information technology devices that widely used by traders in marketing activities. Aside from being a communication tool, traders also utilize smartphones to obtain market information and communicate about products and services to consumers. This study aims to analyze profile and perceptions of fruit traders in using smartphones as a marketing communication tool. This research employed quantitative method and descriptive analysis using five point Likert scale to examine  the  perception of fruit traders in Yogyakarta City. The results revealed that traders adopted smartphones on fruit marketing communication due to it perceived to provide a relative advantage, with a high level of ease of use, visible benefits, and low complexity and risk. Furthermore, Samsung, Telkomsel, and WhatsApp were brands of smartphones, telecommunications providers, and social media applications mostly chose by traders.

A dynamic source model for the San Fernando earthquake

1978 ◽  
Vol 68 (6) ◽  
pp. 1555-1576
Author(s):  
Michel Bouchon
Keyword(s):  
Fault Plane ◽  
High Stress ◽  
Time History ◽  
High Strength ◽  
High Amplitude ◽  
Tectonic Stress ◽  
Source Model ◽  
Dynamic Crack ◽  
San Fernando ◽  
High Level

abstract We model the San Fernando earthquake as a propagating rupture in a half-space, using for the slip-time-history on the fault plane analytical expressions which approximate the slip functions of dynamic crack models obtained by Das and Aki (1977a, b). We synthesize the strong ground motions and accelerations at the Pacoima Dam site and compute the teleseismic signals for different models of cracks. Three major featuras of the data–the strong pulse associated with the beginning of the rupture, the high acceleration phase on the Pacoima Dam records, and the presence of ripples on the teleseismic seismograms–which are not compatible with a smooth rupture process, are well explained by a crack with barriers model where the rupture encounters, along the fault plane, barriers or obstacles of high strength materials which may remain unbroken after the passage of the rupture front. A high-stress drop (400 to 500 bars) is required in the hypocentral area to explain the high-amplitude short-duration first pulse of the teleseismic records. This indicates a high level of tectonic stress in the area. A study of the earthquake series following the main shock shows that the aftershocks which took place in the region where major slipping occurred during the earthquake may represent the release of some of the barriers.

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