Effect of Retained Austenite and Non-Metallic Inclusions on the Mechanical Properties of Resistance Spot Welding Nuggets of Low-Alloy TRIP Steels
Autor: | Ignacio Mejía Granados, Víctor H. Baltazar Hernández, Víctor H. Vargas Cortés, Gerardo Altamirano Guerrero, Cuauhtémoc Maldonado Zepeda |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
lcsh:TN1-997
Heat-affected zone Materials science Weldability resistance spot welding low-alloy trip steel non-metallic inclusions 02 engineering and technology Welding 020501 mining & metallurgy law.invention chemistry.chemical_compound law Formability General Materials Science Spot welding lcsh:Mining engineering. Metallurgy Tensile testing Austenite retained austenite Metallurgy Metals and Alloys 021001 nanoscience & nanotechnology x-ray microdiffraction and magnetometry 0205 materials engineering chemistry Non-metallic inclusions 0210 nano-technology |
Zdroj: | Metals, Vol 9, Iss 10, p 1064 (2019) Metals Volume 9 Issue 10 |
ISSN: | 2075-4701 |
Popis: | The combination of high strength and formability of transformation induced plasticity (TRIP) steels is interesting for the automotive industry. However, the poor weldability limits its industrial application. This paper shows the results of six low-alloy TRIP steels with different chemical composition which were studied in order to correlate retained austenite (RA) and non-metallic inclusions (NMI) with their resistance spot welded zones to their joints&rsquo final mechanical properties. RA volume fractions were quantified by X-ray microdiffraction (µ SXRD) while the magnetic saturation technique was used to quantify NMI contents. Microstructural characterization and NMI of the base metals and spot welds were assessed using scanning electron microscopy (SEM). Weld nuggets macrostructures were identified using optical microscopy (OM). The lap-shear tensile test was used to determine the final mechanical properties of the welded joints. It was found that NMI content in the fusion zone (FZ) was higher than those in the base metal and heat affected zone (HAZ). Whereas, traces of RA were found in the HAZ of highly alloyed TRIP steels. Lap-shear tensile test results showed that mechanical properties of spot welds were affected by NMI contents, but in a major way by the decomposition of RA in the FZ and HAZ. |
Databáze: | OpenAIRE |
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