电焊机2026，Vol.56Issue(8)：80-88,9.DOI:10.7512/j.issn.1001-2303.2026.08.08
稀土Pr对800MPa级高强钢焊接熔敷金属组织和性能的影响
Influence of Rare Earth Pr on Microstructure and Properties of Weld Deposited Metal of 800 MPa Grade High-Strength Steel
摘要
Abstract
The effects of rare earth praseodymium(Pr)on the growth behavior of austenite,ferrite,bainite and martensite as well as inclusion nucleation in the microstructure of weld deposited metal of 800 MPa grade high-strength steel were investi-gated via in-situ observation,and the correlations among chemical composition,microstructure and mechanical properties were systematically characterized.The results show that the weld metal without Pr6O11 addition exhibits coarsened austenite grains,with inclusions segregated at grain boundaries.Upper bainite nucleates and grows along grain boundaries,which hin-ders the growth of acicular ferrite,leading to the lowest impact toughness of 44 J for the deposited metal.The addition of 1％Pr6O11 facilitates the refinement and spheroidization of inclusions and austenite grains in deposited metal.Acicular ferrite preferentially nucleates and grows inside austenite grains to partition the original austenite matrix,restraining the formation and growth of upper bainite and martensite,thereby generating a multiphase partitioned microstructure,and the optimal im-pact toughness reaches 72 J.When the addition amount of Pr6O11 rises to 2％,excessive rare earth elements reduce the oxy-gen content within inclusions and decrease the number of nucleation sites for acicular ferrite.The volume fractions of upper bainite and martensite increase correspondingly,which deteriorates the mechanical properties of deposited metal and reduces the impact toughness to 61 J.关键词
高强钢/Pr6O11/熔敷金属/微观组织/力学性能/原位观察Key words
high-strength steel/Pr6O11/weld deposited metal/microstructure/mechanical property/in-situ observation分类
矿业与冶金引用本文复制引用
石雨龙,张天理,方乃文,王伟光,刘淇,李伟,马青军,信国松..稀土Pr对800MPa级高强钢焊接熔敷金属组织和性能的影响[J].电焊机,2026,56(8):80-88,9.基金项目
泰山产业领军人才工程(2024001) （2024001）
国家自然科学基金项目(51804196) （51804196）
