超临界水中的腐蚀及其影响溶液参数概述

简介了高温超临界水中材料普遍存在的腐蚀及主要作用机制。超临界水中的腐蚀强弱主要由密度、温度、pH值、溶剂的电化学特性和作用离子的强弱决定,腐蚀包括粒间腐蚀、蚀损斑、普通腐蚀、压力破裂腐蚀。腐蚀产物和反应物的作用强弱及其在高温水中的溶解度对腐蚀起着主要作用。溶解和分解过程受到溶剂的密度、离子产物的影响,这两个参数值较高有利于离子反应,从而加快了腐蚀的电化学反应。并展望了未来的研究需求。

Corrosion in Supercritical Water and Influence of Solution Parameter

The common corrosion phenomena and the predominant corrosion mechanisms in high-temperature and supercritical water were introduced.Corrosion in aqueous systems up to supercritical temperatures was determined by several solution-dependent.Solution-depending factors were the density,temperature,pH value,and electrochemical potential of the solution,and aggressiveness of the attacking anions.Corrosion phenomena observed included intergranular corrosion,pitting,general corrosion,and stress corrosion cracking.The solubility and dissociation of both attacking species and corrosion products played the most important role for corrosion in high-temperature water.Both solubility and dissociation processes were strongly influenced by the density,and the ionic product,respectively,of the solvent.An outlook was also given for the future research needs.