Post-weld Heat Treatment and Groove Angles Affect the Mechanical Properties of T92/Super 304H Dissimilar Steel Weld Joints

2018 ◽  
Vol 37 (7) ◽  
pp. 649-654 ◽  
Author(s):  
Wang Shuo ◽  
Wei Limin ◽  
Cheng Yi ◽  
Tan Shuping
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Weld Metal ◽  
Arc Welding ◽  
Post Weld Heat Treatment ◽  
Steel Weld ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
Gas Tungsten Arc ◽  
Weld Heat

AbstractThe microstructures and mechanical properties of dissimilar weld joints between T92 and Super 304H steels were investigated. Dissimilar weld joints with four groove angles were constructed using gas tungsten arc welding. The results showed that post-weld heat treatment improved the mechanical properties of the dissimilar weld joints. The optimal groove angle for T92/Super 304H dissimilar weld joints was found to be 20°, considering mechanical properties. Furthermore, the transformation from equiaxed dendrites to columnar dendrites was observed in the weld metal. Epitaxial growth and delta ferrites were found around the fusion line between the Super 304H and the weld metal.

scholarly journals Post-Weld Heat Treatment of API 5L X70 High Strength Low Alloy Steel Welds

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5801
Author(s):  
Houman Alipooramirabad ◽  
Anna Paradowska ◽  
Shahrooz Nafisi ◽  
Mark Reid ◽  
Reza Ghomashchi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Arc Welding ◽  
High Strength ◽  
Post Weld Heat Treatment ◽  
Slight Reduction ◽  
Weld Joints ◽  
Flux Cored Arc Welding ◽  
Weld Heat

High Strength Low Alloy (HSLA) steels are the materials of choice in pipeline construction with the API X70 grade as the steel for the majority of pipeline networks constructed during the late 20th and early this century. This paper reports on the influence of Post-Weld Heat Treatment (PWHT) on the reduction of residual stresses, resulting changes in the microstructure, and mechanical properties of a multi-pass, X70 HSLA steel, weld joints made by a combined Modified Short Arc Welding (MSAW) and Flux Cored Arc Welding (FCAW) processes. Neutron diffraction results highlighted high magnitude of tensile residual stresses, in excess of yield strength of both parent and weld metal, in the as-welded specimen (~650 MPa), which were decreased substantially as a result of applying PWHT (~144 MPa). Detailed microstructural studies are reported to confirm the phase transformation during PWHT and its interrelationship with mechanical properties. Transmission Electron Microscopy (TEM) analysis showed polygonization and formation of sub-grains in the PWHT specimen which justifies the reduction of residual stress in the heat-treated weld joints. Furthermore, microstructural changes due to PWHT justify the improvement in ductility (increase in the elongations) with a slight reduction in yield and tensile strength for the PWHT weld joint.

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.

Effect of Post Weld Heat Treatment on Weld Hardness Quality of P91 Welded Pipes

2015 ◽  
Vol 799-800 ◽  
pp. 377-381
Author(s):  
Mohd Amin Abd Majid ◽  
Muhammad Sarwar
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welded Joint ◽  
Post Weld Heat Treatment ◽  
Bead Geometry ◽  
Construction Sites ◽  
Weld Heat

Quality of a weld produced is generally evaluated by different parameters such as weld size, bead geometry, deposition rate, hardness and strength. A common problem that has been faced at the construction sites is to obtain a good welded joint having the required strength with minimal detrimental residual stresses to avoid any premature cracking due to high variation of hardness. In order to address this issue and to attain good weld quality, this study has been made to comprehend the effect of the post weld heat treatment on P91 material welds produced by TIG welding. Findings from the studies indicate that the PWHT has significant influence on the weld hardness of Alloy Steel-A335 P91 pipes. It is eminent that during cooling, after welding of P91, quenched martensite was formed in the HAZ that results in an increased hardness to an undesirable level of more than 250HB. PWHT at temperature of 760°C for 2 hours has good influence on mechanical properties as the hardness decreases and turns out to be uniformly distributed. If the PWHT is correctly carried out, the hardness of parent metals, heat affected zones and weld metal can be brought into the required limits to avoid any premature cracking due to high variation of hardness.

Effect of Post Weld Heat Treatment on Mechanical Properties of 17-4-PH Stainless Steel Welds

2015 ◽  
Vol 830-831 ◽  
pp. 181-184
Author(s):  
A. Sam Prabhakar ◽  
M. Agilan ◽  
T. Venkateswaran ◽  
D. Sivakumar ◽  
P.G. Venkatakrishnan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Heat Treatment Condition ◽  
Post Weld Heat Treatment ◽  
Thick Sheet ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Steel Welds ◽  
Weld Heat

Precipitation hardening stainless steel (17-4-PH) of 3 mm thick sheet was welded by gas tungsten arc welding (GTAW) process using a matching composition filler wire of ER 630. The welds were subjected to various post weld heat treatment (PWHT) cycles viz., H900, H1025 and H1150. Tensile properties (UTS, 0.2% YS, and % EL.), hardness survey across the weld and detailed optical microscopy have been carried-out on as-welded and after different PWHT conditions samples. Results showed that H900 heat treatment condition attained higher mechanical properties than H1025 and H1150.

TEM Investigations of the Microstructure of 7CrMoVTiB10-10 Steel Weld Metal

2015 ◽  
Vol 231 ◽  
pp. 101-106
Author(s):  
Krzysztof Pańcikiewicz ◽  
Anna Zielińska-Lipiec
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Weld Metal ◽  
Important Implication ◽  
Post Weld Heat Treatment ◽  
Steel Weld ◽  
Technological Properties ◽  
Cooling Conditions ◽  
Steel Weld Metal ◽  
Weld Heat

7CrMoVTiB10-10 (T24) steel is recommended for fabrication of boiler components such as water walls, water panels or headers without post weld heat treatment (PWHT). The chemical composition of this steel and cooling conditions after welding influence the susceptibility to cracking in weld metal during and after welding. TEM investigations showed that in the as-welded microstructure mixtures of bainite and martensite were dominating. This has an important implication for technological properties.

The Causes of Low Impact Strength of T23 Steel Weld Joints

2015 ◽  
Vol 226 ◽  
pp. 103-106
Author(s):  
Janusz Adamiec ◽  
Izabela Pikos ◽  
Michał Stopyra
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Weld Metal ◽  
Post Weld Heat Treatment ◽  
Weld Joints ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
The Impact ◽  
Welding Technique ◽  
Weld Heat

T23 is modern bainitic steel designed for use in supercritical boilers. According to producer’s data weldability of this steel is good enough to avoid post-weld heat treatment. However, some of the T23 weld joints in as-welded condition have not met the minimal ductility requirement. The impact test revealed significant differences between the joints in as-welded and heat treated condition. Metallographic and fractographic examinations have been conducted in order to explain those differences. The specimens with low impact strength were characterized by brittle fracture and non-tempered martensite presence in weld metal. It was concluded that avoiding formation of disadvantageous structure in weld metal requires conducting of post weld heat treatment or applying multi-pass welding technique with annealing run.

Microstructural Evolution and Resulting Mechanical Properties of Weld Joints upon Flux Cored Arc Welding and Post-Weld Heat Treatment

2009 ◽  
Vol 283-286 ◽  
pp. 439-446 ◽  
Author(s):  
Hui Yu ◽  
Kee Sam Shin ◽  
Ji Ling Dong ◽  
Dae Hwang Yoo ◽  
Woong Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Impact Toughness ◽  
Arc Welding ◽  
Compositional Analysis ◽  
Post Weld Heat Treatment ◽  
Grain Structure ◽  
Automatic Welding ◽  
Weld Joints ◽  
Flux Cored Arc Welding ◽  
Weld Heat

The objective of this study is to determine the mechanism of the dramatic increase of impact toughness at low temperatures after post-weld heat treatment on weld joints. In this study, weld joints using two semi-automatic welding consumables were fabricated by flux cored arc welding with subsequent PWHT at 660°C for 65 min and 195 min, respectively. Tests of the tensile and yield strength, microhardness and impact toughness, were carried out. The microstructure was inspected by optical, scanning electron, and transmission electron microscopy in addition to compositional analysis using energy dispersive spectrometry. PWHT was observed to result in grain coarsening, sub-grain structure formation and decrease of the dislocation density. The increase of impact toughness is attributed to the relieved thermal stress, the inclusions and precipitations, softening of the structure, dislocation recovery and sub-grain structure.

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