滨海盐土中典型供水管材的腐蚀规律

Corrosion Rules of Typical Water Supply Pipes in Coastal Saline Soil

为了获得滨海土壤中球墨铸铁、灰口铸铁和碳钢3种常见供水管材料的腐蚀规律,将试片埋在现场,采用多项指标综合评价法作评价。结果显示:3种管材在滨海土壤中主要发生局部腐蚀;土壤中的Cl-含量越高,腐蚀速率越高;夏季的腐蚀速率明显高于冬季,试片表面的腐蚀产物层初期会促进腐蚀,随后有保护作用且逐渐增强;3种管材的腐蚀产物主要为铁的氧化物、羟基氧化物和羟基氯化物,高Cl-环境下生成的β-Fe OOH和铁的羟基氯化物对3种管材的腐蚀均有促进作用。

Ductile iron, grey cast iron and carbon steel are three kinds of common water supply pipe materials.The method of field buried test was used to obtain the actual corrosion rules of three kinds of materials in coastal saline soil, combined with multiple indexes comprehensive evaluation.Results showed that the localized corrosion was the main corrosion type in coastal saline soil, and the corrosion rate increased with the increase of Cl^- content in the soil. Besides, the corrosion rate in summer was obviously higher than that in winter.The corrosion product layer promoted the corrosion at the early stage of the field buried test and afterwards the protective effect gradually increased. Iron oxides, hydroxyl oxides and hydroxyl chlorides were the main corrosion products of three kinds of pipes.The β-FeOOH and hydroxyl chloride generated in the high Cl^- content environment promoted the soil corrosion of three kinds of pipes.