Effect of Heat Treatment on Impact Strength of Welded Joint Metal Made by Submerged-Arc Welding

The present study aims at investigating the effect of submerged arc welding fluxes for enhanced corrosion resistance of structural steel welds. By varying the basicity index of submerged arc welding fluxes the corrosion resistance and mechanical properties of weld metal such as tensile strength, impact strength, microhardness in submerged arc weldments were evaluated. The result shows that with the increase in bascity index tensile strength of weld specimen reduced while impact strength and microhardness value increased. Maximum microhardness (288 HV) was observed for flux 2 while base metal show minimum microhardness value (205 HV). Flux 5 gives maximum impact strength (94.17 J) as compared to the base metal (80 J). This is due to the reduced content of oxygen in weld metal which increases the weld metal impact toughness. Corrosion resistance of weld specimen increased as compared to the base metal. Ductile fracture mode and shear lip or tears were observed in the weld zone. Shear dimples and shear lips were more severe in base metal as well as weld metal impact specimens due to the rapid effect of external forces on the impact test. The banded microstructure of delta ferrite and austenite was observed in the base metal. Fine grains of ferrite and pearlite at the center and edges were present in the weld zone.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.681.364 ◽

2011 ◽

Vol 681 ◽

pp. 364-369

Author(s):

Maria José Marques ◽

António Castanhola Batista ◽

Joana Rebelo-Kornmeier ◽

Michael Hofmann ◽

Joao P. Nobre ◽

...

Keyword(s):

Heat Treatment ◽

Residual Stress ◽

Arc Welding ◽

Submerged Arc Welding ◽

The Other ◽

Steel Plates ◽

Stress Fields ◽

Stress Profiles ◽

Filler Metals ◽

Submerged Arc

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.

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Microstructure and Mechanical Properties of Submerged Arc Welding Filled with Ni Wire Dissimilar Joints Comprising SUS304 and Q245R

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1780 ◽

2014 ◽

Vol 936 ◽

pp. 1780-1785

Author(s):

Peng Xian Zhang ◽

Peng Zhao ◽

Yan Quan Cui

Keyword(s):

Mechanical Properties ◽

Weld Metal ◽

Alloy Steel ◽

Arc Welding ◽

Molten Pool ◽

Welded Joint ◽

Submerged Arc Welding ◽

Low Alloy Steel ◽

Allocation Process ◽

Submerged Arc

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.

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