scholarly journals Influence of Post-Weld Heat Treatment on Microstructure and Toughness Properties of 13MnNiMoR High Strength Low Alloy Steel Weld Joint

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5336
Author(s):  
Songya Tian ◽  
Fan Xu ◽  
Genyuan Zhang ◽  
Adnan Saifan ◽  
Bassiouny Saleh ◽  
...  

Weld and base metals require hot or cold working during the steel equipment manufacturing process. As a result, the components should be subjected to a normalizing heat treatment in order to recover their mechanical properties. In this study, the submerged-arc welding of the high strength low alloy (HSLA) thick steel plate(13MnNiMoR) is adapted for the vessel head under the normalizing and tempering heat treatment. The findings showed that the material toughness decreases after heating to simulate a vessel head forming process. The stamping process is carried out under the conditions of 980 °C for one hour, normalizing at 920 °C for 1 h and tempering between 600–660 °C for 2 h, respectively. The martensite-austenite (M-A) constituent is distributed in granular bainite and the boundary of austenite in island constituent. Therefore, it was deemed to be the most detrimental to Charpy-V impact toughness. Between normalizing and tempering, intercritical normalizing at 740 °C was added. As a result of the ferrite with fine particles M-A constituent, the toughness increases significantly.

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.


2018 ◽  
Vol 108 (10) ◽  
pp. 639-645
Author(s):  
P. Groche ◽  
J. Günzel ◽  
T. Suckow

Zur Ausnutzung der hohen spezifischen Festigkeit und folglich Eignung als Leichtbauwerkstoff von EN AW-7075 bedarf es neben den Umform- auch Wärmebehandlungsprozessen, die im Folgenden in den Umformprozess integriert werden und die Prozesskette somit deutlich kürzer und effizienter gestalten. Dieser Fachbeitrag zeigt, welches Produktivitäts- und Leichtbaupotenzial durch eine Inline-Wärmebehandlung erschlossen werden kann.   To be able to exploit the high specific strength and thus suitability of EN AW-7075 as a lightweight construction material, it requires not only forming but also heat treatment processes. The latter become integrated into the forming process and thus make the process chain significantly shorter and more efficient. This paper points out the potential for productivity and lightweight construction to be tapped by inline heat treatment.


1987 ◽  
Vol 3 (02) ◽  
pp. 111-118
Author(s):  
John C. West

Steels with 50 ksi and up yield points usually acquire their strength from some form of heat treatment. Most of these steels, 11/2 in. thick and up, must be welded using sustained preheat and controlled interpass temperatures, plus controlled welding heat input of approximately 50 to 60 kJ/in. These two items can add as much as 50 percent to the cost of submerged-arc welding, and increases of up to 30 percent are common for manual welding when compared with lower-strength steels previously used. To reduce costs, a quenched and precipitation-hardened steel, ASTM A710 Grade A Class 3, with a high degree of weldability, was tested. This steel, which can be welded without sustained preheat and almost unlimited heat input, has been extensively tested in thicknesses from 21/4 through 6 in. Although this steel costs more than the usual quenched-and-tempered plates at these strength levels, reductions of 40 to 75 percent in welding labor costs are probable. In addition, sizeable material savings should be realized when these items are used in place of HY-80 and HY-100.


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


Author(s):  
Qing Li ◽  
Guangxu Cheng ◽  
Mu Qin ◽  
Zaoxiao Zhang

In this paper, the mechanical properties and microstructural changes of 2.25Cr1Mo0.25V steel under different heat treatment and welding process were investigated. The heat treatment of steel during practical processing is taken as a reference. Different heat treatment time are used to obtain samples with different condition. Automatic submerged arc welding was used to obtain welding sample. The mechanical properties of different samples are obtained by tensile test; the evolution of microstructure and precipitates of different sample with heat treatment and welding was studied on scanning electron microscopy. The experimental results show that with the increase of heat treatment time, the strength of the samples decreases and the plasticity remains nearly constant. Heat treatment also affects the precipitation of carbides; the longer the heat treatment time is, the more precipitates are. Compared with the base metal, the welding metal sample has higher strength. The amount of precipitates in welding metal is much larger than it in base metal. The research on precipitation shows that there are different kinds of precipitates which have different morphologies in welding metal.


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