On the Failure Mode of Resistance Spot Welded Hsla 420 Steel / Tryb Uszkodzenia Zgrzewanych Spoin Stali Hsla 420

Failure mode of resistance spot welds (interfacial vs. pullout) is a qualitative measure of resistance spot weld performance. Considering adverse effect of interfacial failure mode on the vehicle crashworthiness, process parameters should be adjusted so that the pullout failure mode is guaranteed ensuring reliability of spot welds during vehicle lifetime. In this paper, metallurgical and mechanical properties of HSLA 420 resistance spot welds are studied with particular attention to the failure mode. Results showed that the conventional weld size recommendation of 4t0:5 (t is sheet thickness) is not sufficient to guarantee pullout failure mode for HSLA steel spot welds during the tensile-shear test. Considering the failure mechanism of spot welds during the tensileshear test, minimum required fusion zone size to ensure the pullout failure mode was estimated using an analytical model. Fusion zone size proved to be the most important controlling factor for peak load and energy absorption of HSLA 420 resistance spot weld.

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Minimum fusion zone size required to ensure pullout failure mode of resistance spot welds during tensile-shear test

Metallic Materials ◽

10.4149/km_2010_3_197 ◽

2021 ◽

Vol 48 (03) ◽

pp. 197-202

Author(s):

M. POURANVARI ◽

S. P. MARASHI

Keyword(s):

Failure Mode ◽

Fusion Zone ◽

Shear Test ◽

Zone Size ◽

Tensile Shear ◽

Spot Welds ◽

Resistance Spot ◽

Resistance Spot Welds ◽

Pullout Failure

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Effect of weld nugget size on failure mode and mechanical properties of microscale resistance spot welds on Ti–1Al–1Mn ultrathin foils

Advances in Mechanical Engineering ◽

10.1177/1687814018785283 ◽

2018 ◽

Vol 10 (7) ◽

pp. 168781401878528 ◽

Cited By ~ 3

Author(s):

Feng Chen ◽

Shiding Sun ◽

Zhenwu Ma ◽

GQ Tong ◽

Xiang Huang

Keyword(s):

Mechanical Properties ◽

Failure Mode ◽

Failure Modes ◽

Mechanical Performance ◽

Weld Nugget ◽

Interfacial Failure ◽

Spot Welds ◽

Resistance Spot ◽

Resistance Spot Welds ◽

Pullout Failure

We use tensile–shear tests to investigate the failure modes of Ti–1Al–1Mn microscale resistance spot welds and to determine how the failure mode affects the microstructure, microhardness profile, and mechanical performance. Two different failure modes were revealed: interfacial failure mode and pullout failure mode. The welds that fail by pullout failure mode have much better mechanical properties than those that fail by interfacial failure mode. The results show that weld nugget size is also a principal factor that determines the failure mode of microscale resistance spot welds. A minimum weld nugget size exists above which all specimens fail by pullout failure mode. However, the critical weld nugget sizes calculated using the existing recommendations are not consistent with the present experimental results. We propose instead a modified model based on distortion energy theory to ensure pullout failure. Calculating the critical weld nugget size using this model provides results that are consistent with the experimental data to high accuracy.

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