Surface characterization and pickling characteristics of the oxide scale on duplex stainless steel
Površinska karakterizacija in lastnosti luženja oksidne plasti na dupleksnem nerjavnem jeklu

english

2011

volume 45, issue 4

Inštitut za kovinske materiale in tehnologije
(Obvezni izvod spletne publikacije)

Mixtures of hydrofluoric (HFsub(aq)) and nitric acids (HNOsub3) used for the pickling of stainless steels to remove thick oxide scale generate waste liquids with a high HF concentration. The oxide formation during production annealing and the subsequent pickling response in mixed acids have been studied. A cost reduction and a procedure optimization can be achieved by the use of the proper concentration of mixed acids and a low pickling temperature. In this work, new mixtures of both with a high pickling efficiency for solutions designed for duplex stainless steel are checked. The experiments were carried with mixtures consisting of mass fractions 0.5-4.0 % HFsub(aq) and 12.5-22.0 % HNOsub3 at room and elevated temperatures. The goal of the presented work was to determine the optimal pickling time with respect to the temperature and the acid mixture concentration.

14.08.2012