Residual Stress Fields after Heat Treatment in Cladded Steel of Process Vessels

2011 ◽  
Vol 681 ◽  
pp. 364-369
Author(s):  
Maria José Marques ◽  
António Castanhola Batista ◽  
Joana Rebelo-Kornmeier ◽  
Michael Hofmann ◽  
Joao P. Nobre ◽  
...  

The influence of the heat treatment on the residual stress fields of weld cladded samples is discussed in this paper. The samples were elaborated from carbon steel plates, cladded in one of the faces with stainless steel filler metals by submerged arc welding. After the cladding process some of the samples were submitted to heat treatments with different parameters: one at 620° C for a holding time of 1 hour and the other at 540° C for a period of ten hours. The in‑depth residual stress profiles were determined by neutron diffraction. The results shown that the sample treated to 620 °C, presented the highest residual stress relaxation. The corresponding heat treatment has the industrial benefit to be shorter than the other heat treatment.

2017 ◽  
Vol 1143 ◽  
pp. 52-57
Author(s):  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Bogdan Georgescu ◽  
Octavian Mircea ◽  
Melat Bormambet

The paper addresses the development of advanced welding technologies with two and three solid wires for joining of HSLA API-5l X70 (High-strength low-alloy) steel plates with thickness of 19.1 mm. The experiments were performed using a multi-wire Submerged Arc Welding (SAW) system that was developed for welding of steels with solid, tubular and cold wires, in different combinations. The main goal of the research was to assess the mechanical performances of the welded joints achieved by multi-wire SAW technology and then to compare them with the single wire variant, as reference system. The welded samples were firstly subjected to NDT control by examinations with liquid penetrant, magnetic particle, ultrasonic and gamma radiation, with the aim of detecting the specimens with flaws and afterwards to reconsider and redesign the corresponding Welding Procedure Specifications (WPS). The defect-free welded samples were subjected to tensile, Charpy V-notch impact and bending testing in order to analyse and report the mechanical behaviour of API-5l X70 steel during multi-wire SAW process. The experimental results were processed and comparatively discussed. The challenge of the investigation was to find the appropriate welding technology which responds simultaneously to the criteria of quality and productivity. Further research on metallurgical behaviour of the base material will be developed, in order to conclude the complete image of the SAW process effects and to understand how the multi-wire technologies affect the mechanical and metallurgical characteristics of the API-5L X70 steel used in pipelines fabrication.


Author(s):  
J. A. Francis ◽  
H. J. Stone ◽  
S. Kundu ◽  
R. B. Rogge ◽  
H. K. D. H. Bhadeshia ◽  
...  

Residual stress in the vicinity of a weld can have a large influence on structural integrity. Here the extent to which the martensite-start temperature of the weld filler metal can be adjusted to mitigate residual stress distributions in ferritic steel welds has been investigated. Three single-pass groove welds were deposited by manual-metal-arc welding on 12mm thick steel plates using filler metals designed to have different martensite-start temperatures. Their residual stress distributions were then characterised by neutron diffraction. It was found that a lower transformation temperature leads to a potentially less harmful stress distribution in and near the fusion zone. The experimental method is reported and the results are interpreted in the context of designing better welding consumables.


2014 ◽  
Vol 783-786 ◽  
pp. 859-866 ◽  
Author(s):  
Dong Sheng Liu ◽  
Chong Xiang Yue ◽  
Huan De Chen ◽  
Bing Gui Cheng

Key parameters for thermomechanical control process (TMCP) and integrated welding operations have been determined to industrialize extra high strength micro-alloyed low carbon SiMnCrMoNiCu steel plates for bridge applications. Confocal Scanning Microscope was used to make In-situ observation on austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate transformation behavior of the TMCP conditioned austenite. Integrated industrial rolling trial was conducted to correlate the laboratory observations and commercial production of the plates. Microstructure factors affecting the toughness of the steel were analyzed. Submerged-Arc Welding (SMAW) trails were conducted and the structures and mechanical properties of the weld joints characterized. The representative plate with thickness of 60 mm consisted of acicular ferrite (AF) + refined polygonal ferrite (PF) + granular bainite (GB) across the entire thickness section exhibit yield strength (YS) greater than 560 MPa in transverse direction and excellent Charpy V Notch (CVN) impact toughness greater than 100 J at-40 °C in the parent metal and the weld joints. These provide useful integrated database for producing advanced high strength steel plates via TMCP. Keywords: Thermo-Mechanical Control Process;Weathering Steel Plate for Bridge; Submerged-Arc Welding without Preheating


2012 ◽  
Vol 3 (3) ◽  
pp. 228-233
Author(s):  
R. Dhollander ◽  
S. Vancauwenberghe ◽  
W. De Waele ◽  
N. Van Caenegem ◽  
E. Van Pottelberg

The assembly of large structures made out of thick steel plates requires a welding process bywhich multiple wires can be used simultaneously. To reproduce these industrial processes in a researchenvironment, OCAS has invested in a multiwire submerged arc welding (SAW) setup. In this multiwiresetup, up to five wires in tandem configuration can be used.The objective of this master thesis is to establish a deeper knowledge of process parameters used to weldsteel plates in a thickness range of 12,7 up to 25 mm, by means of the submerged arc welding process.Based on literature, a test matrix is composed in which the number of wires, the plate thickness and otherweld parameters are the variables. In addition, a specific plate preparation for each plate thickness isderived from the literature. The preformed weld trails will be evaluated on weld bead geometry andmetallographic properties. There is further experimental examination required, which will result in therevising of the matrix.


Author(s):  
K. Satyambabu ◽  
N. Ramachandran

Many important engineering applications such as nuclear reactors, ships, pipes and pressure vessels are shell-like structures made with weldments. For such a structure, a major problem is the development of residual stress and distortion due to welding. Residual stresses in weldments significantly affect stress corrosion cracking, hydrogen-induced cracking and fatigue strength in welded structures. As-welded components generally have certain amount of residual stresses caused by the application of intense heat or thermal loading at the weld joint, formed due to non-uniform cooling rates at different points in the weld metal and heat affected zones. Presence of residual stresses in a component is detrimental as they may lead to failure below the design stress value and also affect many important properties including the life of a welded component. Welding induced residual stresses can significantly increase the fracture driving force in a weldment and also contribute to brittle fracture. The thermal cycle imposed on any welded object causes thermal expansions and contractions which are not uniform. Quantitative measurement of residual stresses is essential to take remedial measures such as change in the welding technique, optimizing welding parameters (heat input, electrode diameter etc,), change in the weld groove design and post-weld heat treatment for minimizing the residual stresses. Residual stress measurements after post-weld treatment would also ensure the adequacy of stress relief treatment. To have an investigation into these aspects, residual stresses due to Manual Metal Arc Welding and Submerged Arc Welding were measured nondestructively with Ultrasonic technique. Residual stress distribution for Shielded Metal Arc Welding and Submerged Arc Welding were compared and the present studies emphasized, that Shielded Metal Arc Welding gave higher compressive stresses than Submerged Arc Welding. Further, to substantiate the studies, commercial finite element analysis software ANSYS 5.6 was used for modeling of manual metal arc welded joint. The results obtained by ANSYS were compared with those by Ultrasonic method.


2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Enlin Yu ◽  
Yi Han ◽  
Haixiang Xiao ◽  
Ying Gao

As oil and gas pipelines develop toward large throughput and high pressure, more and more attention has been paid to welding quality of oil pipelines. Submerged arc welding is widely applied in manufacturing of large-diameter welded pipes, and the welding quality has an impact on pipeline safety. With a multiwire submerged arc welding test platform and real-time temperature measurement system, temperature measurement has been done for multiwire submerged arc welding process with and without flux coverage, respectively. As a result, thermal cycling curves in both cases have been obtained, and convection and radiation coefficients of flux-covered X80 pipeline steel in air-cooled environment have been corrected. By using sysweld software, a finite-element computational model was set up for microstructure and residual stress in the weld zone of multiwire longitudinal submerged arc welding. Comparative experiment has been done to obtain welding temperature field with relatively high accuracy. Calculation and analysis of residual stress versus preheat residual stress decreased with increasing preheat temperature up to 100 °C, meanwhile content of bainite in microstructure fell, facilitating reduction in residual stress to some extent. This study provides quantitative reference for further optimization of welding parameters and improvement in weld mechanical properties.


Metallurgist ◽  
2018 ◽  
Vol 62 (3-4) ◽  
pp. 254-260 ◽  
Author(s):  
L. A. Efimenko ◽  
T. S. Esiev ◽  
D. V. Ponomarenko ◽  
S. P. Sevast’yanov ◽  
I. Yu. Utkin

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