Dramatic improvement of impact toughness for the fabricating of low-carbon steel components via submerged arc additive manufacturing

The present work investigated the effects of Al, Si, and N content on the impact toughness of the coarse-grained heat-affected zone (CGHAZ) of Ti-containing low-carbon steel. Simulated CGHAZ of differing Al, Si, and N contents were prepared, and Charpy impact toughness was determined. The results were interpreted in terms of microstructure, especially martensite-austenite (M-A) constituent. All elements accelerated ferrite transformation in CGHAZ but at the same time increased the amount of M-A constituent, thereby deteriorating CGHAZ toughness. It is believed that Al, Si, and free N that is uncombined with Ti retard the decomposition of austenite into pearlite and increase the carbon content in the last transforming austenite, thus increasing the amount of M-A constituent. Regardless of the amount of ferrite in CGHAZ, its toughness decreased linearly with an increase of M-A constituent in this experiment, indicating that HAZ toughness is predominantly affected by the presence of M-A constituent. When a comparison of the effectiveness is made between Al and Si, it showed that a decrease in Si content is more effective in reducing M-A constituents.

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Effect of Ti, Al and Mg Addition on the Impact Toughness of Heat Affected Zone in Low Carbon Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.143 ◽

2009 ◽

Vol 79-82 ◽

pp. 143-146

Author(s):

Jiang Hua Ma ◽

Dong Ping Zhan ◽

Zhou Hua Jiang ◽

Ji Cheng He

Keyword(s):

Carbon Steel ◽

Impact Toughness ◽

Heat Affected Zone ◽

Low Carbon Steel ◽

Optical Microscope ◽

Carbon Steels ◽

Low Carbon ◽

Welding Simulation ◽

Mg Addition ◽

The Impact

In order to understand the effects of deoxidizer such as aluminium, titanium and magnesium on the impact toughness of heat affected zone (HAZ), three low carbon steels deoxidized by Ti-Al, Mg and Ti-Mg were obtained. After smelting, forging, rolling and welding simulation, the effects of Al, Ti and Mg addition on the impact toughness of HAZ in low carbon steel were studied. The inclusion characteristics (size, morphology and chemistry) of samples before welding and the fracture pattern of the specimens after the Charpy-type test were respectively analyzed using optical microscope and scanning electron microscopy (SEM). The following results were found. The density of inclusion in Ti-Mg deoxidized steel is bigger than Ti-Al deoxidized steel. The average diameter is decreased for the former than the latter. The addition of Ti-Mg can enhance the impact toughness of the HAZ after welding simulation. The maximal value of the impact toughness is 66.5J/cm2. The complex particles of MgO-TiOx-SiO2-MnS are most benefit to enhance impact toughness. The improvement of HAZ is attributable to the role of particle pinning and the formation of intergranular ferrite.

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Environmental Behavior of Low Carbon Steel Produced by a Wire Arc Additive Manufacturing Process

Metals ◽

10.3390/met9080888 ◽

2019 ◽

Vol 9 (8) ◽

pp. 888 ◽

Cited By ~ 7

Author(s):

Ron ◽

Levy ◽

Dolev ◽

Leon ◽

Shirizly ◽

...

Keyword(s):

Corrosion Resistance ◽

Additive Manufacturing ◽

Carbon Steel ◽

Stress Corrosion ◽

Environmental Behavior ◽

Low Carbon Steel ◽

General Corrosion ◽

Low Carbon ◽

Corrosion Performance ◽

Wire Arc Additive Manufacturing

: Current additive manufacturing (AM) processes are mainly focused on powder bed technologies, such as electron beam melting (EBM) and selective laser melting (SLM). However, the main disadvantages of such techniques are related to the high cost of metal powder, the degree of energy consumption, and the sizes of the components, that are limited by the size of the printing cell. The aim of the present study was to evaluate the environmental behavior of low carbon steel (ER70S-6) produced by a relatively inexpensive AM process using wire feed arc welding. The mechanical properties were examined by tension testing and hardness measurements, while microstructure was assessed by scanning electron microscopy and X-ray diffraction analysis. General corrosion performance was evaluated by salt spray testing, immersion testing, potentiodynamic polarization analysis, and electrochemical impedance spectroscopy. Stress corrosion performance was characterized in terms of slow strain rate testing (SSRT). All corrosion tests were carried out in 3.5% NaCl solution at room temperature. The results indicated that the general corrosion resistance of wire arc additive manufacturing (WAAM) samples were quite similar to those of the counterpart ST-37 steel and the stress corrosion resistance of both alloys was adequate. Altogether, it was clearly evident that the WAAM process did not encounter any deterioration in corrosion performance compared to its conventional wrought alloy counterpart.

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