PCrNi3MoV高强钢带状组织在调质工艺中的显微特征  

Microscopic characteristics of banded structure in PCrNi3MoV high-strength steel in quenching and tempering

作　　者：杜云飞 白瑞 吴璞 张亚琴 Du Yunfei;Bai Rui;Wu Pu;Zhang Yaqin(Department of Mechanical Engineering,Taiyuan Institute of Technology,Taiyuan Shanxi 030008,China)

机构地区：[1]太原工业学院机械工程系,山西太原030008

出　　处：《金属热处理》2024年第3期135-140,共6页Heat Treatment of Metals

基　　金：山西省基础研究计划(自由探索类)青年项目(202303021212278);山西省高等学校科技创新项目(2022L546);太原工业学院引进人才科研资助项目(2023KJ006)。

摘　　要：PCrNi3MoV高强钢中合金元素在提升淬透性和力学性能的同时,也会在钢中因合金元素偏析形成带状组织。采用光学显微镜、扫描电镜、透射电镜及电子探针研究了PCrNi3MoV钢中带状组织在不同热处理工艺下的显微特征,结果表明,带状组织在PCrNi3MoV钢的不同热处理阶段始终存在,其微观组织构成及表现形式各不相同;淬火态下,PCrNi3MoV钢带状组织呈大尺寸晶粒和小尺寸晶粒交替分布的显微特征;回火态下,带状组织细晶区马氏体板条束尺寸细小,碳化物析出密度高。带状组织细晶区的显微硬度高于其粗晶区,主要与C元素及Cr、Mo、Mn和V等合金元素的在细晶区偏聚,从而使得该区域内细晶强化及析出强化效应增强。Alloying elements in PCrNi3MoV high-strength steel can improve the hardenability and mechanical properties, but also lead to banded structure by their segregation. Microscopic characteristics of banded structure in the PCrNi3MoV steel in different heat treatment processes were studied by means of optical microscope, scanning electron microscope, transmission electron microscope and electron probe microanalysis. The results show that the banded structure presents at different heat treatment stages of the tested steel, though the microscopic composition and characteristics are different. In the quenched state, the banded structure is characterized by alternating distribution of large and small size grains. In the tempered state, the size of martensitic lath in fine-grained region of the banded structure is smaller, the precipitation density of the carbides is higher, and the microhardness of the fine-grained region is higher than that in the coarse-grained region, which is attributed to the segregation of C and Cr, Mo, Mn and V elements in the fine-grained region, the grain strengthening and precipitation strengthening effects are more pronounced than those in the coarse-grained region.

关 键 词：Cr-Ni-Mo-V系钢 带状组织 调质处理 元素偏析 

分 类 号：TG156[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]