EVALUATION OF THE RELATIONSHIPS BETWEEN METALLIC IONS MIGRATED FROM AISI304 AND AISI321 STAINLESS STEEL SAMPLES INTO FOOD SIMULANT SOLUTIONS AT VARIOUS STIRRING DEGREES

Abstract

The  objective  of  this  work  was  to  assess  through  statistical  methods  the  relationship between  metallic  ions  migrated  from  AISI304  and  AISI321  stainless  steel  food  samples  into  acid simulant solutions depending on the stirring degrees of corrosive environments. Principal Component Analysis method (PCA) was used to fulfill the purpose aimed at. The metallic samples were immersed into corrosive solutions at diferent stirring  degrees: 0 r/min (stationary environment), 125 r/min and 250  r/min.  Acetic  acid  solutions  in  bidistilled  water  were  used  as  food  simulant  environment.  After
conducting  the  migration  tests, the  concentration  of Cr,  Mn,  Fe  and Ni  ions  migrated  from  AISI304 stainless steel samples into corrosive solutions and Ti, Cr, Mn, Fe and Ni ions concentration migrated from  AISI321  stainless  steel  samples  were  analyzed.  These  concentrations  were  analyzed  by  mass spectrometry  with  inductively  coupled  plasma  (ICP-MS).  In  order  to  characterize  the  diffusion processes  occurring  under  accelerated  corrosion,  the  experimental  data  obtained  were  statistically processed in two  steps: analysis of the correlation  between variables based on Pearson’s  correlation matrix  and  analysis  of  relationships  between  variables  through  the  Principal  Component  Analysis.
PCA method has identified the two significant principal components that explain more than 93% of the original  data  variance.  Significant  correlations  between  the  metallic  ions  migrated  into  corrosive solutions stirred at 125 and 250 r/min were found.