烧结机箅条腐蚀损耗原因分析及改进措施

Cause analysis and improvement measures for corrosive bured-out of sinter machine grate bar

针对烧结机配用酸泥后,箅条腐蚀烧损加剧、消耗量异常升高、生产过程中掉箅条次数显著增加等造成工况波动和成本升高的情况,采用化学成分分析、微观腐蚀形貌观察和金相组织结构分析等手段对箅条腐蚀烧损加剧的原因进行了分析。分析结果表明:酸泥中的硫化物是导致箅条发生腐蚀失效的主要原因,而箅条中含碳量较高导致部分晶界附近贫铬严重是加速箅条腐蚀的另一原因。通过采取烧结停配酸泥、箅条成分优化调整、铺底料厚度调整、箅条压辊位置调整、强化隔热套维护等有效措施,使得箅条消耗量降低,每月生产过程中补炉条次数控制在3次左右,烧结机运行稳定性得到提升。

Aiming at such situations as acceleration of the corrosive burned-out rate,exceptional consumption and increasingly breaking down of grate bar during sintering production after adding proportion of acid sludge in the sintering raw mix,which lead to vibration of sintering process and increase of product cost,the cause of the abnormal corrosive burned-out rate of grate bar was analyzed by means of chemical analysis,micro corrosive morphology inspection and the metallurgical microstructure analysis. The research result shows that the sulfide in the acid sludge is the main cause of the grate bar failure,and the higher carbon content in the grate bar material which leads to severe poor chromium phenomenon near the grain boundary also speeds up the corrosion of the grate bar. A series of effective measures such as no addition of acid sludge,optimization of the grate bar chemical contents,adjustment of the hearth layer height and the position of the grate bar push roller,enhancement of the maintenance of the heat insulation set,etc. have been taken to reduce the consumption of the grate bar,the breaking down times of the sintering machine for replacing the failed grate bars has been reduced to about 3 times per month,and the stabilization of the sintering process was improved.