scholarly journals Engineered Weld Design: Are Composite Welds Likely in the Future?

2008 ◽  
Vol 580-582 ◽  
pp. 307-310 ◽  
Author(s):  
D.L. Olson ◽  
Young Do Park ◽  
S. Liu ◽  
J.E. Jackson ◽  
A.N. Lasseigne-Jackson ◽  
...  
Keyword(s):  
Weld Metal ◽  
Welding Process ◽  
Potential Method ◽  
Structural Features ◽  
Gas Composition ◽  
Metal Solidification ◽  
High Toughness ◽  
Low Temperature Creep ◽  
Metal Properties ◽  
Welding Consumables

Utilizing alternating welding process parameters, deposition practices, and welding consumables, particularly during multiple pass welding, it is possible to improve a variety of weld metal properties. There are available a number of phenomena occurring during welding that allow weld metal designers the ability to generate macro- and micro-structural features amenable to implementation of composite theory. These phenomena include solidification microsegregation during dendrite growth, gas-metal reactions between the selected alternating shielding gas composition and weld pool, and solidification microstructural orientation during welding. Additional methods of producing composite welds including specially designed weld compositions, weld metal solidification modification by arc pulsing, and dual wire deposition may be utilized to achieve single pass and multipass composite weld metal deposition. Composite welds are a potential method to solve challenging demands such as high-toughness at low temperature, creep strength at high temperature, and customized design for corrosion, wear, or cracking resistance.

The effect of welding process and shielding atmosphere on the AlMg4.5Mn weld metal properties

2013 ◽  
Vol 104 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Radica Prokić Cvetković ◽  
Olivera Popović ◽  
Meri Burzić ◽  
Radomir Jovičić ◽  
Sandra Kastelec Macura ◽  
...  
Keyword(s):  
Weld Metal ◽  
Welding Process ◽  
Metal Properties

Effect of the FCAW Welding Process and Post Weld Heat Treatment on the Properties and Microstructure of the Weld Joints of Heat Treated 4330V Steel

2015 ◽  
Vol 809-810 ◽  
pp. 437-442
Author(s):  
Jacek Górka ◽  
Michał Miłoszewski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Weld Metal ◽  
Heat Input ◽  
Large Diameter ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
High Toughness ◽  
Interpass Temperature ◽  
Weld Heat

4330V is a high strength, high toughness, heat treatable low alloy steel for application in the oil, gas and aerospace industries. It is typically used for large diameter drilling parts where high toughness and strength are required. The research describes the effect of preheat temperature, interpass temperature, heat input, and post weld heat treatment on strength, hardness, toughness, and changes to microstructure in the weld joint. Welding with the lower heat input and no post weld heat treatment resulted in optimal mechanical properties in the weld metal. Austempering at 400 °C resulted in optimal mechanical properties in the HAZ. Increasing preheat and interpass temperature from 340 °C to 420 °C did not improve Charpy V-notch values or ultimate tensile strength in the weld metal or heat affected zones. The higher temperature increased the width of the heat affected zone. Austempering at 400 °C reduced HAZ hardness to a level comparable to the base metal. Both tempering and austempering at 400 °C for 10 hours reduced toughness in the weld metal.

A New Method for Reducing Diffusible Hydrogen in Weld Metal

2012 ◽  
Author(s):  
Susan Fiore ◽  
Steve Barhorst ◽  
Mario Amata ◽  
Joe Bundy
Keyword(s):  
Weld Metal ◽  
Raw Materials ◽  
Shielding Gas ◽  
Feeding Problems ◽  
Diffusible Hydrogen ◽  
Flux Cored Arc Welding ◽  
Hydrogen Assisted Cracking ◽  
Wire Feeding ◽  
Metal Properties ◽  
Welding Consumables

The effect of hydrogen on weld metal and weld heat-affected zones (HAZ) has been well established over many years. The potential for hydrogen-assisted cracking increases as the strength of the steel increases. High fuel costs have driven the need for lower weights in the transportation and shipbuilding industries, and increased regulations have driven the need for higher safety factors in the pipeline industry. As a result, many industries are requiring higher and higher base metal strengths. The push for higher strength steels has resulted in an increased demand for ultra-low hydrogen welding consumables and processes. Manufacturers of flux-cored arc welding (FCAW) electrodes have generally attacked the problem of weld metal hydrogen through the use of raw materials that react with hydrogen to take it out of solution, by baking the wires in-process, and by using special drawing techniques and lubricants to minimize hydrogen pick-up. Unfortunately, many of the potential solutions result in electrodes that have poor operability, wire feeding problems, and/or increased welding fume. Hobart Brothers has recently developed a method of producing very low-hydrogen weld deposits, which utilizes fluorine-containing gas compounds in the weld shielding gas. The modified shielding gas has no effect on the weld metal properties or the operation of the welding electrodes. This paper provides details of the method, along with test results that have been achieved using a number of flux- and metal-cored electrodes representing a variety of American Welding Society (AWS) classifications.

TIG Overlap Welding Affecting Hard-Faced Weld Metal Properties on JIS-S50C Carbon Steel

2020 ◽  
Vol 861 ◽  
pp. 52-56
Author(s):  
Kittipong Kimapong ◽  
Voraya Wattanajitsiri ◽  
Sakchai Chantasri ◽  
Surat Triwanapong
Keyword(s):  
Wear Resistance ◽  
Carbon Steel ◽  
Weld Metal ◽  
Metal Layer ◽  
Welding Process ◽  
Welding Current ◽  
Dilution Effect ◽  
Tig Welding ◽  
Cored Wire ◽  
Metal Properties

This paper aimed to study an overlap distance (OL) of hard-faced welding bead in a tungsten inert gas (TIG) welding on the JIS-S50C carbon steel surface. Hard-faced weld metal was produced on an outside surface of the cylinder, using TIG welding with a high chromium flux-cored wire electrode. Welding process parameters were a welding current of 150–210 A and a hard-faced layer of 1–3. The experimental results were summarized as follows. An increase in welding current increased the weld width and the penetration but decreased the weld convex. It also increased the hardness and wear resistance of hard-faced weld metal. The increase of a weld overlap distance resulted in a decrease in the dilution effect in weld metals and an increase in the hardness and wear resistance. An increase in the hard-faced weld metal layer also resulted in a decrease in the dilution effect, resulting in an increase in the hardness and wear resistance.

The Effect of Double Pass GMAW Process on Microstructure and Mechanical Properties of Aa 6061-T6 Joining Plates

2012 ◽  
Vol 510-511 ◽  
pp. 98-104 ◽  
Author(s):  
S.R.S. Bakar ◽  
M.Y. Ahmad ◽  
Muhammad Faizol Ahmad Ibrahim ◽  
A. Jalar ◽  
S.J.S. Djalil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Base Metal ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Double Pass ◽  
Metal Solidification ◽  
Microstructure And Mechanical Properties ◽  
First Pass ◽  
Welding Technique

This paper presents an investigation on microstructure and mechanical properties of welded AA 6061-T6 plate using filler metal ER 4043 in the Gas Metal Arc Welding (GMAW) process. Double pass welding technique on both sides of 5 mm thick plate or more is required to provide sufficient weld pool in the joint. The weld metal of the first welding pass exhibits finer microstructure than the second welding pass. The size of Mg2Si precipitations in the heat-affected zone (HAZ) region is larger than in the base metal due to the welding process that reheats the alloy from the T6 condition above the eutectic temperature. Rapid cooling of the first pass and moderate cooling rate for the second pass during weld metal solidification eventually resulted in significantly change the shape and size in the microstructure that had affected the hardness and mechanical properties. Comparisons made to the base metal on the hardness test results found that the hardness of first pass weld metal dropped by 15%, and by 37.5% for the second weld metal, while the hardness at the boundaries of the first and second weld metals dropped by 32.5%. The ultimate tensile strength and strain of the weld joint with ER 4043 also decreased by 48% and 94% respectively. Based on the findings of the study, it is concluded that even though the double sided welding technique is able to overcome shallow weld penetration to avoid stress concentration that leads to the fatigue failure, the metallurgical changes eventually contributes to degradation of mechanical properties.

Fundamental Prediction of Steel Weld Metal Properties

1991 ◽  
Vol 113 (4) ◽  
pp. 327-333
Author(s):  
S. Ibarra ◽  
D. L. Olson ◽  
S. Liu
Keyword(s):  
Weld Metal ◽  
Heat Input ◽  
Plate Thickness ◽  
Carbon Equivalent ◽  
Steel Weld Metal ◽  
Functional Forms ◽  
Metal Properties ◽  
Welding Consumables ◽  
And Behavior ◽  
Selection Of

Empirically derived expressions are commonly used to predict specific steel weldment properties. These expressions usually consider only constitutional considerations and are limited to their ability to predict the influence of the thermal experience (heat input, weld preparation, and plate thickness). Carbon equivalent and basicity index are examples of such predictive expressions. This paper reviews some of the existing expressional forms and introduces new functional forms that are based on metallurgical engineering concepts. Forms for equations which can predict weld metal properties and behavior as a function of composition are proposed. Methodology for including cooling rate in the predictive equations is also suggested. The concept of developing iso-property diagrams that allow better selection of welding consumables with variations in heat input is introduced and discussed.

Effect of Shield Gas Composition on Cold Cracking Susceptibility of YS 600 MPa Flux Cored Arc Weld Metal

2015 ◽  
Vol 53 (7) ◽  
pp. 480-487 ◽  
Author(s):  
Namhyun Kang ◽  
Guo Xian ◽  
Myungjin Lee ◽  
Junghoon Lee
Keyword(s):  
Weld Metal ◽  
Cold Cracking ◽  
Gas Composition

Combining CaO–SiO2–TiO2 and CaO–SiO2–Al2O3 ternary phase systems for design of bimetallic welds

2021 ◽  
Vol 235 (8) ◽  
pp. 1271-1283
Author(s):  
Deepak Bhandari ◽  
Rahul Chhibber ◽  
Lochan Sharma ◽  
Navneet Arora ◽  
Rajeev Mehta
Keyword(s):  
Weld Metal ◽  
Power Plants ◽  
Ternary Phase ◽  
Desirability Function ◽  
Manganese Content ◽  
Research Work ◽  
Welding Process ◽  
Delta Ferrite ◽  
Electrode Coating ◽  
Phase Systems

The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants. The occurrences of welding defects generally depend on the filler electrode as well as the electrode coatings during shielded metal arc welding process. This study involves the design of austenitic stainless steel welding electrodes for SS304L–SA516 bimetallic welds. The objective of research work includes the novel design of Al2O3–TiO2–CaO–SiO2 coatings by combining two ternary phase systems using extreme vertices mixture design methodology to analyze the effect of key coating constituents on the weld metal chemistry and mechanical properties of the welds. The significant effect of electrode coating constituent CaO on weld metal manganese content is observed which further improves the toughness of bimetallic weld joints. Various regression models have been developed for the weld responses and multi objective optimisation approach using composite desirability function has been adopted for identifying the optimized set of electrode coating compositions. The role of delta ferrite content in promoting the favourable solidification mode has been studied through microstructural examination.

scholarly journals Residual stresses in thermite welded rails: significance of additional forging

2020 ◽  
Vol 64 (7) ◽  
pp. 1195-1212
Author(s):  
B. Lennart Josefson ◽  
R. Bisschop ◽  
M. Messaadi ◽  
J. Hantusch
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welding Process ◽  
Surface Zone ◽  
Fe Model ◽  
Uneven Surface ◽  
Residual Stress Field ◽  
High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

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