La对低合金超高强度钢40CrNi2Si2MoVA的夹杂物及断裂韧性的影响
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第一作者：龚伟
通讯作者：李花兵
合写作者：王承,王鹏飞,姜周华,王瑞
发表刊物：钢铁研究学报(英文版)
卷号：28
DOI码：10.1007/s42243-021-00579-1
刊物所在地：中国
摘要：The effect of La on inclusions and fracture toughness of 40CrNi2Si2MoVA steel was investigated via the optical
microscope, scanning electron microscope, image software and electronic universal testing machine. The results reveal that
the inclusions in steel without La are mainly MnS and Al2O3–MnS, while the inclusions in steels with La primarily contain
La–O–S, La–S and other rare earth complex inclusions contain P and As. La–O–S and La–S are formed under the
steelmaking temperature and act as the nucleation core of rare earth complex inclusions containing P and As. According to
the segregation model, La–O–S–P–As and La–S–P–As are formed through chemical reactions during the solidification
stage. As La content in steels increases from 0 to 0.032 mass%, the average spacing of inclusions is gradually increased
from 5.28 to 15.91 lm. The volume fraction of inclusions in steels containing less than 0.018 mass% La approaches
0.006%; however, it is significantly improved to 0.058% when La content is increased to 0.032 mass%. With the increase
in La content, the fracture toughness is firstly improved from 63.1 to 80.0 MPa m1/2 due to the increase in average spacing
of inclusions and then decreases to 69.6 MPa m1/2 owing to the excessive increase in volume fraction of inclusions. The
optimal fracture toughness is found in 40CrNi2Si2MoVA steel with 0.018 mass% La.
项目来源：国家自然科学基金委面上项目
关键字：40CrNi2Si2MoVA steel; La; Inclusion; Thermodynamic calculation; Fracture toughness
论文类型：SCI
学科门类：工学
文献类型：JCR 三区
一级学科：冶金工程
页面范围：1408–1416
是否译文：否