冷却速率和Nb微合金化对25MnV非调质钢组织和硬度的影响
Effects of cooling rate and Nb microalloying on microstructure and hardness of 25MnV non-quenched and tempered steel
刘运娜 1孙笠灿 2戴观文 1刘献达 1宋仁伯 2张朝磊3
作者信息
- 1. 河钢集团石钢公司,河北 石家庄 050031
- 2. 北京科技大学材料科学与工程学院,北京 100083
- 3. 北京科技大学碳中和研究院,北京 100083
- 折叠
摘要
设计了含V和含V-Nb两种成分体系的非调质锻钢,在Gleeble-3800热模拟机上进行了单次压缩试验,研究了冷却速率对V和V-Nb微合金非调质钢组织和硬度的影响.结果表明,冷却速率对钢的显微组织和硬度有显著影响.V钢和V-Nb钢在连续冷却条件下,在0.1～0.5℃/s冷却速率范围内,随着冷却速率的增加,铁素体含量减少,珠光体含量增多,组织得到细化;在1～3 ℃/s冷却速率范围内,随着冷却速率的增加,组织进一步细化,同时开始发生贝氏体相变,促进了硬度的提高.Nb元素的加入生成了大尺寸的(V,Nb)(C,N)沉淀颗粒,通过钉扎晶界和诱导晶内铁素体生成进一步细化了晶粒,同时Nb元素对C原子的溶质拖拽效应降低了V-Nb钢中的珠光体含量.在0.1～0.5 ℃/s冷却速率范围内,V钢较高的硬度(218～242 HV)是因为其更高的珠光体含量;在1～3 ℃/s冷却速率范围内,V-Nb钢较高的硬度(256～291 HV)是因为组织细化作用和更高的贝氏体含量.
Abstract
Effect of cooling rate on microstructure and hardness of two non-quenched and tempered forged steels microalloyed with V and V-Nb was studied by single compression test carried out on a Gleeble-3800 thermal simulator.The results show that the cooling rate has a significant effect on the microstructure and hardness of the tested steels.Under the condition of continuous cooling,with the increase of cooling rate in the range of 0.1-0.5 ℃/s,the ferrite content decreases,the pearlite content increases,and the microstructure is refined.With the increase of cooling rate in the range of 1-3 ℃/s,the microstructure is further refined,and bainite transformation begins to occur,which promotes the increase of hardness.The addition of Nb element generates large-size(V,Nb)(C,N)precipitated particles,which further refines the grains by pinning the grain boundary and inducing the formation of intragranular ferrite.At the same time,the solute drag effect of Nb atom on C atom reduces the content of pearlite in the V-Nb steel.The higher hardness(218-242 HV)of the V steel in the cooling rate range of 0.1-0.5 ℃/s is due to its higher content of pearlite,and the higher hardness(256-291 HV)of the V-Nb steel within the cooling rate range of 1-3 ℃/s is due to the refinement of the microstructure and higher bainite content.
关键词
非调质钢/Nb微合金化/冷却速率/微观组织/硬度Key words
non-quenched and tempered steel/Nb microalloying/cooling rate/microstructure/hardness引用本文复制引用
基金项目
河北省重大科技成果转化专项(22281004Z)
河钢集团重点科技项目(HG2022114)
出版年
2024
NETL
NSTL
万方数据