from the conferences organized by TANGER Ltd.
Household appliances often utilize polymer-metal bonding, typically achieved through adhesive bonding or press-fitting techniques. Corrosion resistance is a major factor in household appliances, as corrosion can compromise the functionality and aesthetics of household appliances. Stainless steels are a natural choice. However, the nature of polymer-stainless steel bonds can cause susceptibility to crevice corrosion. Crevice corrosion, a localized attack on stainless steel in confined spaces. This study investigates crevice corrosion in mixer heads fabricated with two different grades of stainless steel (1.4016 and 1.4021). Metallographic analysis revealed a ferritic microstructure with higher chromium content for 1.4016, contributing to its superior corrosion resistance compared to the martensitic structure of 1.4021. Both materials exhibited a critical crevice width of 9-10 µm between the plastic head and the steel shaft, facilitating the entrapment of corrosive solutions (confirmed by EDS analysis) and subsequent crevice corrosion. The PREN (pitting resistance equivalent number) calculation further supported the observed behavior, with 1.4016 boasting a higher value (16-18) compared to 1.4021 (12-14). While PREN offers a valuable indicator, it highlights the importance of design considerations to minimize crevice formation. Here, eliminating the gap between plastic and steel through improved design or sealants emerges as a crucial preventive strategy. This study emphasizes the interplay between material selection and design in mitigating crevice corrosion in household appliances. By understanding the factors influencing corrosion susceptibility, manufacturers can optimize material choices and implement design solutions to ensure the longevity and performance of their products.
Keywords: Crevice corrosion, stainless steel, mixer heads© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.