Welding Metallurgy of
01 Jan 1987-
About: The article was published on 1987-01-01 and is currently open access. It has received 991 citations till now. The article focuses on the topics: Welding.
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Journal Article•
TL;DR: In this article, the effect of small differences in flux basicity on the microstructure and mechanical properties of submerged arc weld metal of Navy HY-100 steel has been investigated, and it was found that an increase in the flux Basicity index from 2.5 to 3.0 (calculated by the formula proposed by Tuliani, Boniszewski and Eaton, 1969, Weld. Met. and Fab. 37 (8): 327-329) led to a decrease in the total oxygen content of the weld metal from 0.034 to 0.027 wt
Abstract: The effect of small differences in flux basicity on the microstructure and mechanical properties of submerged arc weld metal of Navy HY-100 steel has been investigated. It was found that an increase in the flux basicity index from 2.5 to 3.0 (calculated by the formula proposed by Tuliani, Boniszewski and Eaton, 1969, Weld. Met. and Fab. 37 (8): 327-329) led to a decrease in the total oxygen content of the weld metal from 0.034 to 0.027 wt-%. This decrease in weld metal oxygen content led to increasing average nonmetallic inclusion size and an increased propensity for acicular ferrite formation, which were found to increase both the strength and toughness of the weld metal. These results suggest that careful control of the chemistry of both the filler metal and flux is necessary to produce consistently high strength and toughness in weld metal during the submerged arc welding of HY-100 steel.
14 citations
01 Jan 2010
TL;DR: In this paper, the weldability of BA-160 was evaluated using phase transformation techniques to identify martensite as the only austenitic transformation product in the heat-affected zone (HAZ) for both single-pass Low Heat-Input (LHI) and High Heat Input (HHI) conditions.
Abstract: BlastAlloy160 (BA-160) is a high-strength transformation-toughened steel that was developed to meet the material property requirements for blast-resistant Naval applications. The nominal composition of BA-160 is Fe 0.05C 3.65Cu 6.5Ni 1.84Cr 0.1V wt%. Weldability testing techniques were employed to evaluate and quantify the weldability of BA-160 in relation to Naval alloys HY-100, HSLA-100, and HSLA-65. Heat-Affected Zone (HAZ) simulations of BA-160 employed phase transformation techniques to identify martensite as the only austenitic transformation product in the HAZ. The HAZ hardness profile was similar for both single-pass Low Heat-Input (LHI) and High Heat-Input (HHI) conditions; slightly higher hardness was observed for the LHI samples. The maximum hardness of 436 HV and minimum hardness of 347 HV were observed in the Inter-Critical HAZ (ICHAZ) and Coarse-Grained HAZ (CGHAZ) regions, respectively. Slight hardness decreases were observed in both the Sub-Critical HAZ (SCHAZ) and Fine-Grained HAZ (FGHAZ) regions when compared to the Base Metal (BM) hardness of 402 HV. The hardness values were in good agreement with measurements from a Gas Tungsten Arc (GTA) spot weld. The observed hardness trend was attributed to lath martensite and Cu precipitation strengthening mechanisms, as quantified by the Electron Backscatter Diffraction (EBSD) and Atom Probe Tomography (APT) techniques, respectively. Copper segregation to a maximum concentration of 20 at% was measured in the CGHAZ. Hardness recovery in a multi-pass CG + SC HAZ sample, similar to that observed during Postweld Heat Treatment (PWHT), was attributed to the reprecipitation of Cu precipitates during the SCHAZ thermal cycle. Single-pass
14 citations
Cites background from "Welding Metallurgy of"
...Many of these reactions, or complex combinations of reactions, may cause a detrimental effect on the properties of the weld region [11, 13]....
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...The weld thermal cycle is characterized by rapid heating and cooling rates, with negligible hold time at peak temperature [11]....
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...Two major mechanisms responsible for HAZ liquation cracking are the penetration and segregation mechanisms [11]....
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...Solidification cracking is most prevalent in alloys that solidify in the FCC crystal structure, such as Al alloys, austenitic stainless steels, and Ni-base alloys [11]....
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TL;DR: In this paper, the effect of welding speed on solidification cracking susceptibility in type 310S stainless steel using Trans-Varestraint test during laser welding was investigated, and the results showed that the number of solidification cracks and total crack length per bead width increased with welding speeds greater than 1.0 m/min.
Abstract: Solidification cracking occurs as a result of thermal strain and solidification behavior that is determined by welding conditions, especially welding speed. Brittle temperature range (BTR), an important index for evaluating solidification cracking, is used to quantity the effect of welding speed on susceptibility to solidification cracking. However, measurement of BTR using Trans-Varestraint test during laser welding has rarely been studied. The purpose of this work is to investigate the effect of welding speed on solidification cracking susceptibility in type 310S stainless steel using Trans-Varestraint test during laser welding. Solidification cracking and ductility-dip cracking were distinguished by observing fracture surfaces. Compared with traditional Trans-Varestraint test carried out for gas tungsten arc welding, the number of solidification cracks and total crack lengths during laser welding were lower; however, the number density of solidification cracks and total crack length per bead width during laser welding were higher. Both of these values had a tendency to first increase and then decrease slightly with increasing welding speed: the maximum values occurred at approximately 1.5 m/min. Temperature profiles at 0.2 and 1.0 m/min during laser welding were measured by an optical-fiber radiation thermometer combined with in-situ observation using a high-speed camera. BTR was measured using the center crack length along the heat flow in the welding direction. BTR at 1.0 m/min was less than that at 0.2 m/min during laser welding because the maximum crack length appeared at the side of molten pool at welding speeds greater than 1.0 m/min.
14 citations
TL;DR: In this paper, an investigation was conducted to correlate process variables in shielded metal-arc welding (SMAW) and post weld heat treatment on some mechanical properties of low carbon steel weld, and they concluded that there is correlation between the welding current and mechanical proper-ties of weld metal on one hand and normalising temperatures and mechanical properties on the other hand.
Abstract: This investigation was conducted to correlate process variables in shielded metal-arc welding (SMAW) and post weld heat treatment on some mechanical properties of low carbon steel weld. Three hundred and sixty pieces of weld samples were prepared. The samples were welded together using AWS E6013 electrodes with DC arc welding process. Varying welding currents of 100 A, 120 A, 140 A were used with a terminal voltage of 80 V. The weld samples were prepared for hardness, tensile and impact test. The prepared samples were then subjected to normalising heat treatment operation at temperatures of 590°C, 600°C, 620°C, 640°C, 660°C, 680°C, and 700°C. It was observed that increase in welding current led to an increase in hardness and ultimate tensile strength values of as-weld samples while impact strength de-creases. After post heat treatment operation the hardness and ultimate tensile strengths decreases while impact strength increases. From this outcome we conclude that there is correlation between the welding current and mechanical proper-ties of weld metal on one hand and normalising temperatures and mechanical properties on the other hand. As the cur-rent increases the hardness and strength increases but impact strength reduces, while hardness and strength continuously reduces but impact strength increases as normalising temperatures increases.
14 citations
Cites background from "Welding Metallurgy of"
...This favours the formation of columnar dendrites in the weld metal and also increases the level of residual stress in the weld metal [18]....
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TL;DR: In this article, the variation of weld metal chemistry in the multi-pass GMA and P-GMA weld depositions are studied by spark emission spectroscopy, and it is observed that the narrow groove GMA weld joint shows significant variation of welding metal chemistry compared to the conventional V-groove GMA welding joint since the dilution of base metal extends from the deposit adjacent to groove wall to weld center through dissolution by fusion and solid state diffusion.
14 citations
Cites background from "Welding Metallurgy of"
...It is often found that the heterogeneity of weld metal chemical composition, especially for multi-pass welding of thick sections, gives the different weld joint properties primarily due to the repetitive influence of subsequent weld passes on thermal cycles and the dilution of base metal [1,2]....
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...The most significant changes in the properties of weld joints are due to adverse development of residual stress, microstructure and corrosion resistance, etc [2]....
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References
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TL;DR: In this article, the fundamental understanding of structure-properties relationship in automotive steels resistance spot welds is discussed. And a brief review of friction stir spot welding, as an alternative to RSW, is also included.
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