Investigation on Deposited Metal Properties of Homemade Nickel and Nickel-Free Electrodes and Fluxes for Submerged Arc Welding of SA-508 Gr.3 Cl.1

Author(s):  
Le Mei ◽  
Junbao Zhang ◽  
Yifeng Huang ◽  
Yan Yu ◽  
Yong Jiang ◽  
...  

Up to now, two kinds of filler metal with or without nickel element for submerged arc welding have been largely used in the reactor pressure vessel (RPV) manufacturing. In order to study the effect of nickel element on weld metal properties of SA-508 Gr.3 Cl.1, submerged arc welding material with nickel (AWS classification F8P4-EGN-F2N, F2 for short) and welding material without nickel (F8P4-EA3N-A3N, A3 for short) were used; and conventional mechanical properties, low-cycle fatigue test, and proton irradiation analysis of the two weld metals were studied. Results show that the mechanical properties of the two different weld metals are similar, except that the Charpy V-notch impact property of the weld metal with nickel is better than that without nickel; the micro-structures of F2 and A3 weld metals are both composed of ferrite base and granular bainite, but the columnar grain size of F2 weld metal is smaller relatively, which results in better impact property. In addition, the irradiated A3 weld metal has fewer dislocation loops than the irradiated F2 weld metal after the same proton irradiation dose; the irradiated weld metals both have higher micro-Vickers hardness than before.

2014 ◽  
Vol 936 ◽  
pp. 1780-1785
Author(s):  
Peng Xian Zhang ◽  
Peng Zhao ◽  
Yan Quan Cui

Aim at the issue that the bending crack is easy to generate inside dissimilar welded joint of low alloy steel and stainless steel, a new process of submerged arc welding filled with Ni wire is put forward. The influence mechanism of filling quantity of Ni wire to the joint of microstructure evolutions and mechanical properties is mainly explored based on the contrast test of non-filling Ni wire and three different filling speeds of Ni wire. The experiment results indicate that, the filling process of Ni wire supplies austenite forming element, and alters heat allocation process of molten pool. The filling quantity of Ni wire is the quantitative parameter, it is used to control the transition width between low alloy steel and weld metal, also to adjust the peak temperature and holding time at elevated temperature of molten pool. When the value of the filling quantity of Ni wire is determined, the problem of bending crack in the fusion zone of low alloy steel can be solved, and also the overheat damage can be eliminated. At the same time, the grains of weld metal and heat affected zone are refined. And on this basis the plasticity, toughness and microhardness of welded joint can be guaranteed.


Author(s):  
Ramakrishnan Mannarsamy ◽  
S. K. Shrivastava ◽  
Piyush Thakor ◽  
Gautam Chauhan ◽  
S. K. Joshi ◽  
...  

For achieving high productivity multiple wire submerged arc welding such as tandem wire, three wires and five wires submerged arc welding was introduced in recent past years. Due to adding of additional wires in a pipe mill faced process difficulties such as controlling the current supply to each wire and further challenges for consumable design in order to give effective slag characteristics and bead shape control at these higher welding speeds and heat inputs. To gain maximum productivity, welding speed must be as fast as possible (in excess of 2 m/min) consistent with reliable high speed wire feeding and the characteristics of the SAW flux considering these factors in determining the balance of heat input, penetration, bead shape, dilution, weld metal chemistry and mechanical properties such as toughness. Steels containing high strength low alloying elements like Manganese, Molybdenum, Titanium and boron have favorable physical properties such as higher subzero toughness, resistance to improve the mechanical properties because of which there is substantial saving in the material. High strength low alloy steels materials are utilized in offshore and onshore at critical services. However, such benefits can be exploited provided these steels can be welded with appropriate development of welding process such as cold wire addition® in multi wires with process controller using WINCC programmer, Z5 version to give better weldments, which will not compromise the integrity, and operating condition. To obtain higher productivity and quality, it is necessary to develop a welding procedure for butt joint of line pipe steels. This paper describes the recent work carried out by Welspun, in this regard to establish the welding procedure using GMAW and submerged arc welding process and evaluation of mechanical properties. Macro and micro structural analysis were also made to characterize the weld metal properties.


2011 ◽  
Vol 314-316 ◽  
pp. 1163-1166 ◽  
Author(s):  
Zhong Yi Chen ◽  
Yong Lin Ma ◽  
Shu Qing Xing

To research effect of welding thermal cycle on the microstructure and mechanical properties of welded joint, two pieces of 60mm thick plates were welded together using automatic submerged-arc welding (SAW) method with suitable welding parameters. After 17 passes welding, the microstructures and phases of the welded joint was carefully observed and analyzed by using a Carl Zeiss optical microscope in different zones of welded joint, and the surface micro-hardness of the welded joint was measured systematically by using microscopic-hardness tester Lycra. Afterwards, the mechanical properties of the weld metals were measured through stretching. Through a series of measurements and observations, the welding experiment results indicate that effect of welding thermal cycle on the microstructure and mechanical properties of welding joint is great, the grains of the bottom of the weld metal are certainty smaller and more uniform, and the bottom of the weld metal have more excellent mechanical properties.


1996 ◽  
Vol 14 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Kazutoshi ICHIKAWA ◽  
Yukihiko HORII ◽  
Ryuichi MOTOMATSU ◽  
Masami YAMAGUCHI ◽  
Nobutaka YURIOKA

2018 ◽  
Vol 226 ◽  
pp. 03029
Author(s):  
Nikolay V. Kobernik ◽  
Alexander S. Pankratov

The influence of nanoscale refractory titanium carbide particles on the structure and properties of weld metal in automatic submerged arc welding is considered. Composite granules based on nickel were used to introduce the compound into the composition of the weld pool. Two schemes for introducing granules into the weld pool were tested, characterized by different temperature conditions: to the head part of the welding pool with the help of “ligature” and to the tail section with the help of additional filler wire. The prospects of introducing nano-sized titanium carbide into the tail part of the weld pool as part of a flux-cored wire are shown. With this method, the structure of the weld metal is observed to modify: the average size of the primary crystals of the weld metal is reduced by almost 50%. At the same time, the value of the toughness of the weld metal increases: the average value of this index increases by 36%. When titanium carbide is introduced as part of the “ligature” into the head of the weld pool, despite the effect of modifying (reducing the width of the primary crystals by 30%), the average value of the toughness of the weld metal decreases.


2019 ◽  
Vol 53 (2) ◽  
pp. 176-176
Author(s):  
N. P. Aleshin ◽  
M. V. Grigor’ev ◽  
N. V. Kobernik ◽  
R. S. Mikheev ◽  
A. S. Pankratov ◽  
...  

2018 ◽  
Vol 52 (5) ◽  
pp. 440-445
Author(s):  
N. P. Aleshin ◽  
M. V. Grigor’ev ◽  
N. V. Kobernik ◽  
R. S. Mikheev ◽  
A. S. Pankratov ◽  
...  

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