焦炉上升管换热器内筒用310S不锈钢高温腐蚀行为研究

Research on high-temp.corrosion to 310S stainless steel for inner tube of heat exchanger in standpipe

焦炉上升管余热利用作为焦化工序节能减碳、降本增效的重要手段,其换热器内筒材质是关系到上升管安全稳定运行及寿命的关键。选取310S耐热钢,在焦炉上升管内进行了14天的挂片试验,通过观察挂片前后组织与表面氧化腐蚀情况,得出:310S钢板经挂片试验后表面出现厚度约3~5μm的氧化层,氧化层含Cr、Fe、O、Si、Al等元素;且表层有明显的渗氮现象;钢板表层未观察到高温硫化反应现象,也未观察到硫化物腐蚀开裂特征;无明显的组织转变及组织粗化现象,组织中的部分孪晶消失,偏析程度减轻。

The utilization of waste heat from the coke oven standpipe plays an important role in energy saving,carbon reduction,cost reduction,and efficiency enhancement in the coking process.The material of the inner tube of the heat exchanger is crucial to the safe and stable operation and service life of the standpipe.310S heat-resistant steel was selected for 14 day hanging test inside coke oven standpipe.By observing the microstructure and surface oxidation and corrosion before and after hanging,the result demonstrated that the surface of 310S steel plate showed a thickness of about 3~5μm oxidized layer,containing elements such as Cr,Fe,O,Si,Al,etc.;And there is obvious nitriding phenomenon on the surface;No high-temperature vulcanization reaction or sulfide corrosion cracking characteristics were observed on the surface of the steel plate;There is no obvious tissue transformation or coarsening phenomenon,some twinning in the tissue disappears,and the degree of segregation is reduced.