Independence of EPR and PAP tests performed on resistance spot welding joints

ABSTRACT

In the present paper, the possible relationships among the variables of the potentiodynamic anodic polarisation (PAP) test and the electrochemical potentiokinetic reactivation (EPR) test, both performed on resistance spot welding joints of AISI 304 stainless steel, are investigated. Results show that PAP variables are statistically independent from those of EPR, which implies independence between the pitting corrosion behaviour and the degree of sensitisation of the material. Parameters from PAP test are dependent among them, but this association is found noisy since the current density along the passive zone is not exactly constant. The parameters from the EPR test are confirmed as very related, presenting a linear relationship and a high coefficient of determination.

KEYWORDS:

• Resistance spot welding
• AISI 304 stainless steel
• pitting potential
• reactivation charge
• electrochemical potentiokinetic reactivation test
• potentiodynamic anodic polarisation test
• maximal information coefficient
• distance correlation

Acknowledgement

The authors would like to thank Dr L.R. Izquierdo for some advice and comments on this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Virginia Ahedo http://orcid.org/0000-0002-9812-388X

Óscar Martín http://orcid.org/0000-0001-9200-5797

José Ignacio Santos http://orcid.org/0000-0002-6653-043X

Pilar De Tiedra http://orcid.org/0000-0003-2026-3476

José Manuel Galán http://orcid.org/0000-0003-3360-7602

Additional information

Funding

The authors acknowledge support from the Spanish Ministerio de Ciencia e Innovación (MICINN) Project CSD2010-00034 (SimulPast CONSOLIDER-INGENIO 2010).