FTSR薄板坯内部横裂纹形成机理的分析和预防措施  

Analysis on Forming Mechanism of Inner Cross Crack in Concasting Thin Slab Produced by FTSR Process

作　　者：冯运莉[1] 王庆双[1] 谢启川[1] 

机构地区：[1]河北理工大学金属材料工程系,唐山063009

出　　处：《特殊钢》2007年第3期22-24,共3页Special Steel

基　　金：唐山市科学技术研究与发展计划资助项目(编号04204501C-22)

摘　　要：采用Gleeble-3500热模拟机模拟FTSR薄板坯生产工艺,试验了SS330钢板坯(0.06％C)和SS400钢板坯(0.20％C)在600～1 350℃的高温塑性。结果表明,SS400钢在700～900℃的高温塑性高于SS330钢,SS400钢板坯内部产生的横向裂纹是由于柱状晶晶界处硫、氧化物的偏聚,使钢晶界的高温塑性下降所致。通过钢中硫含量由0.015％降低至0.010％,全氧含量由45×10^(-6)降至30×10^(-6),钢中Nn／S≥60,钢水过热度由30～50℃降至20～35℃,铸坯拉速由2.5～6.0 m／min改为3.0～4.5 m／min,控制二冷水量,有效地避免了薄板坯内部横裂纹的产生。The process of thin slab produced by FTSR （ Flexible Thin Slab Rolling） process has been simulated by Gleeble-3500 thermal simulation machine, and the high temperature plasticities of slab of steel SS330 （0. 06% C） and steel SS400 （0. 20% C） 600 - 1 350 ℃ were tested. Results showed that the high temperature plasticity of steel SS400 at 700- 900 ℃ was high than that of steel SS330; the high temperature plasticity decreasing of steel SS400 due to segregation and accumulation of sulphide and oxide at boundary of columnar crystal caused inner cross crack formation in slab. With controll/ng sulphur content in steel decreasing to 0.010% from 0. 015%, total oxygen content to 30 × 10-6 from 45 × 10^-6, superheating degree of molten steel to 20 - 35 ℃ from 30 - 50 ℃, Mn/S in steel ≥60 and modifying slab casting speed to 3.0 -4. 5 m/min from original 2.5 - 6.0 m/min with reasonably controlling secondary cooling water amount, the thin slab inner cross crack was avoided effectively.

关 键 词：FTSR工艺 SS400钢 薄板坯 内部横裂纹 形成机理 

分 类 号：TG142.15[一般工业技术—材料科学与工程]