摘要
采用阶梯式循环淬火+调质工艺对AISI 4330钢中产生的带状缺陷进行了均匀化处理,并探究均匀化处理过程的组织演变及其对力学性能的影响规律。结果表明,原始带状缺陷试样为铁素体+珠光体组织,带状组织评级为3级,EPMA结果显示存在较为严重的C、Cr、Mo元素偏析。经过多次高温淬火+调质,带状缺陷组织转变为由铁素体和含Cr碳化物以及回火索氏体组成的均匀组织,元素偏析得到一定程度的改善,C元素扩散明显,Cr、Mo元素偏析仍存在,阶梯式循环淬火的多次相变过程使得组织得到明显细化。此外,试验钢的力学性能得到提升,抗拉强度达到1200 MPa以上,硬度达到350 HBW左右,-40℃冲击吸收能量达到64.2 J左右,组织细化同时提高了试样的强度及塑韧性,碳化物的大量析出也有利于提高钢的强度。强度和韧性的提升更能满足压裂泵产品使用要求,提高AISI 4330钢使用寿命。
Homogenization treatment of AISI 4330 steel with banding defects was carried out through a step-by-step cyclic quenching and tempering heat treatment processes.The microstructure evolution and its effect on mechanical properties was studied during homogenization process.The results show that the original specimen with banded defects consists of ferrite and pearlite,with a banded structure level of 3.The element segregation of C,Cr,and Mo is significantly revealed by means of electron probe micro-analysis(EPMA).After undergoing multiple high-temperature quenching+quenching and tempering cycles,the microstructure transforms into a homogeneous structure consisting of ferrite,carbides containing Cr,and tempered sorbite.The element segregation is improved to a certain extent.Although the diffusion of C element is evident,segregation of Cr and Mo elements still exists.The step-by-step cyclic quenching process leads to lots of phase transformation,resulting in the refinement of microstructure of the steel.Furthermore,the mechanical properties of the steel are enhanced,resulting in tensile strength exceeding 1200 MPa,hardness of about 350 HBW,and impact absorbed energy at-40℃of about 70 J.The refinement of microstructure contributes to the improvement in both strength and toughness of the specimen.Additionally,the large amount of precipitated carbonitride plays a beneficial role in increasing the strength of the steel.The enhanced strength and toughness characteristics fulfill the requirements of fracturing pump products and their service life.
作者
史长鑫
谷国超
崔树刚
许文花
肖桂勇
吕宇鹏
Shi Changxin;Gu Guochao;Cui Shugang;Xu Wenhua;Xiao Guiyong;Lu Yupeng(School of Materials Science and Engineering,Shandong University,Jinan Shandong 250061,China;Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials,Ministry of Education,Shandong University,Jinan Shandong 250061,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2023年第12期1-6,共6页
Heat Treatment of Metals
基金
国家自然科学基金(52233018)
山东省重点研发(重大创新工程)项目(2020CXGC010305,2021ZLGX01)。
关键词
AISI
4330钢
带状组织
均匀化
组织
性能
AISI 4330 steel
band structure
homogenization
microstructure
properties
