Open AccessPickling behavior of 2205 duplex stainless steel hot-rolled strips in mixed solutions of HNO3-HF
Author(s) -
Jinghua Peng,
Yong Yang,
Moucheng Li
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab81c0
Subject(s) - pickling , dissolution , passivation , materials science , metallurgy , oxide , electrochemistry , annealing (glass) , metal , nuclear chemistry , chemistry , electrode , composite material , layer (electronics)
The pickling behaviour of 2205 DSS hot-rolled strips after annealing and sand blasting was studied in the mixed solutions of HNO 3 -HF using weight loss rate, surface analysis, corrosion potential, and electrochemical impedance spectroscopy measurements. The pickling rate decreased as the concentration of HNO 3 increased in the mixed solutions of x HNO 3 + 25 g l −1 HF ( x = 40 ∼ 200 g l −1 ) at 50 °C due to passivation. The passivating effect of HNO 3 became weak as its concentration was less than 80 g l −1 . The pickling rate increased noticeably when the concentration of HF in the mixed solutions of 120 g l −1 HNO 3 + y HF ( y = 5 ∼ 80 g l −1 ) at 50 °C was increased. The dissolution of the metal under the oxide scale may have changed from the passive state to the active state as the HF concentration was higher than 25 g l −1 . The pickling dissolution accelerated noticeably as the temperature rose from 40 to 60 °C. With the optimised pickling process, 2205 DSS hot-rolled strips can be pickled industrially with good efficiency and surface topography.