厚大断面高炉冷却壁组织及力学性能的控制

Microstructure and Mechanical Properties Control of Blast Furnace Stave Heavy Section

介绍了高炉冷却壁的结构及技术要求,详细阐述了该铸件的生产工艺及过程控制:(1)合理选择炉料,控制主要微量元素总和,使其低于0.15%;(2)根据微量元素总量来控制w(Ce)量;(3)采取低温快速熔炼方式,高温快速短时过热处理工艺,保证冶金质量;(4)铁液出炉前进行适当的铁液预处理,采用含重RE的球化剂,延缓球化衰退,采用堤坝包以及覆盖铁屑的方式,保证球化处理效果。生产结果显示:铸件心部球化级别为3~5级,石墨大小≥4级,铁素体体积分数≥80%,抗拉强度≥415 MPa,伸长率≥7%,符合技术要求。

The structure and the technical requirements of blast furnace stave was introduced. Casting production technology and process control were elaborated.（ 1 ）Choice charge reasonably. Control major trace elements and make it less than 0.15%. （2）Control Ce amount according to all trace elements. （3）Use tow temperature fast melting method and short-term high- temperature rapid over-heat processing technology to ensure metallurgical quality. （4）Use pretreatment before liquid iron pouring. Use nodulizer containing heavy RE to slow the decline of nodulizer. Dam package and covering iron filings were used to ensure nodulizer treatment effect. Production results showed：Nodularity rate on casting core part was level 3-5. The size of graphite was over 4 grade. The volume of ferrite was more than 80%. Tensile strength and elongation were more than 415 MPa and 7%. That were in line with technical requirements.