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

作　　者：刘运娜 孙笠灿 戴观文 刘献达 宋仁伯[2] 张朝磊[3] Liu Yunna;Sun Lican;Dai Guanwen;Liu Xianda;Song Renbo;Zhang Chaolei(HBIS Group Shijiazhuang Iron and Steel Co.,Ltd.,Shijiazhuang Hebei 050031,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Institute for Carbon Neutrality,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[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

出　　处：《金属热处理》2024年第8期31-36,共6页Heat Treatment of Metals

基　　金：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)。

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。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 

分 类 号：TG142.1[一般工业技术—材料科学与工程]