摘要
在“双碳”战略驱动下,82B盘条生产工艺由传统长流程向电炉短流程的转型已成必然,但对短流程工艺生产的盘条近芯部出现马氏体异常组织的成因尚缺乏系统研究。为此,通过金相组织观察和对宏、微观偏析的定量分析与热模拟试验,并与传统长流程工艺生产的82B盘条组织进行对比分析,研究了再生钢铁原料+电炉短流程工艺生产的82B盘条中出现马氏体异常组织的成因,并提出了改进措施。结果表明:短流程-82B盘条近芯部附近Mn、Cr元素的偏析程度较长流程-82B盘条的严重,且残余元素Ni含量偏高使得82B盘条的C曲线右移,将马氏体生成的临界冷速由7℃/s降低至3℃/s,使相同冷速下短流程-82B盘条的马氏体含量均高于长流程-82B盘条。基于实验结果,对盘条的生产工艺进行调控,即将钢坯均热段温度由(1 120±10)℃提高至(1 160±10)℃、加热和均热段保温时间保持在100~120 min,盘条宏观偏析现象得到了明显改善,抑制了马氏体异常组织的生成。
Driven by the"dual-carbon"strategy,the transformation of 82B wire rod production processes from traditional long-process to electric furnace short-process has become inevitable.However,there is still a lack of systematic research on the causes of abnormal martensite structures near the core of wire rods produced by short-process technology.To address this,this study investigated the causes of abnormal martensite structures in 82B wire rods produced by recycled steel materials+electric furnace short-process through metallographic observation,quantitative analysis of macro/micro-segregation,and thermal simulation tests,combined with comparative analysis of 82B wire rod structures produced by traditional long-process technology.The results show that the segregation levels of Mn and Cr elements near the core of short-process 82B wire rods are more severe than those of long-process 82B wire rods.This segregation,along with the higher residual Ni content,shifts the C-curve of 82B steel to the right,reduces the critical cooling rate for martensite formation from 7°C/s to 3°C/s.As a result,the martensite content of short-process 82B wire rods under the same cooling rate is higher than that of long-process 82B wire rods.Based on experimental results,process adjustments were applied,including increasing the soaking temperature of billets from(1120±10)℃to(1160±10)°C and maintaining the heating and soaking holding times at 100-120 min.These adjustments significantly improved macro-segregation and suppressed the formation of abnormal martensite structures.
作者
李东升
吕普明
吴咏锦
狄增文
朱子轩
张朝磊
LI Dongsheng;LÜPuming;WU Yongjin;DI Zengwen;ZHU Zixuan;ZHANG Chaolei(Xuansteel Company,HBIS Group Co.,Ltd.,Xuanhua 075100,China;Institute for Carbon Neutrality,University of Science and Technology Beijing,Beijing 100083,China;Institute of Steel Sustainable Technology,Liaoning Academy of Materials,Shenyang 110169,China)
出处
《轧钢》
北大核心
2025年第4期79-85,118,共8页
Steel Rolling
基金
河钢集团有限公司重点科技项目(No.HG2023236)。
关键词
长流程工艺
短流程工艺
82B盘条
马氏体
异常组织
宏观偏析
微观偏析
long-process technology
short-process technology
82B wire rod
martensite
abnormal structure
macro-segregation
micro-segregation
