Investigation of liquid metal embrittlement during resistance spot welding of martensitic steel with zn jet vapor-deposited coating

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F21%3A43922976" target="_blank" >RIV/60461373:22310/21:43922976 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mdpi.com/1996-1944/14/5/1125#cite" target="_blank" >https://www.mdpi.com/1996-1944/14/5/1125#cite</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/met11111813" target="_blank" >10.3390/met11111813</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Investigation of liquid metal embrittlement during resistance spot welding of martensitic steel with zn jet vapor-deposited coating

Popis výsledku v původním jazyce

Advanced high-strength steels protected by zinc coatings have contributed to a reduction in CO2 emissions in the automotive industry. However, the liquid metal embrittlement (LME) of the Fe/Zn couple induced by simultaneously acting stresses and high temperatures during resistance spot welding could be the cause of unexpected failure. We investigated the possible risk of LME in spot-welded martensitic steel with Zn jet vapor-deposited coating and its influence on weld strength. The weld nugget cross-sections were analyzed (optical microscopy, SEM-EDS), and their tensile shear strengths were compared with their uncoated counterparts. LME cracks were observed in all samples meeting the process window (6, 6.5, 7 kA) located at the edge of the sheet/electrode indentation area. The frequency and length of cracks increased with current, and the occurrence of Zn within cracks indicated the LME mechanism. The shear tests showed the Zn-coated sample underwent a decrease in tensile shear strength that was most evident at a welding current of 7 kA (13.2%). However, LME was excluded as a cause of lower strength. The decrease was attributed to the smaller nugget diameter and the thin slit of Zn coating remaining in the weld notch. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Název v anglickém jazyce

Investigation of liquid metal embrittlement during resistance spot welding of martensitic steel with zn jet vapor-deposited coating

Popis výsledku anglicky

Advanced high-strength steels protected by zinc coatings have contributed to a reduction in CO2 emissions in the automotive industry. However, the liquid metal embrittlement (LME) of the Fe/Zn couple induced by simultaneously acting stresses and high temperatures during resistance spot welding could be the cause of unexpected failure. We investigated the possible risk of LME in spot-welded martensitic steel with Zn jet vapor-deposited coating and its influence on weld strength. The weld nugget cross-sections were analyzed (optical microscopy, SEM-EDS), and their tensile shear strengths were compared with their uncoated counterparts. LME cracks were observed in all samples meeting the process window (6, 6.5, 7 kA) located at the edge of the sheet/electrode indentation area. The frequency and length of cracks increased with current, and the occurrence of Zn within cracks indicated the LME mechanism. The shear tests showed the Zn-coated sample underwent a decrease in tensile shear strength that was most evident at a welding current of 7 kA (13.2%). However, LME was excluded as a cause of lower strength. The decrease was attributed to the smaller nugget diameter and the thin slit of Zn coating remaining in the weld notch. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Metals

ISSN

2075-4701

e-ISSN

—

Svazek periodika

11

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

14

Strana od-do

—

Kód UT WoS článku

—

EID výsledku v databázi Scopus

2-s2.0-85118745773