Normalizing Effect of Heat Treatment Processing on 17-4 PH Stainless Steel Manufactured by Powder Bed Fusion

Metals

Tae Bum Kim¹  Jongcheon Yoon¹  Yong Son¹  Si-Mo Yeon¹  Kyunsuk Choi²  Tea-Sung Jun³  Seung Ho Lee⁴ 

[1] Advanced Joining & Additive Manufacturing R&D Department, Korea Institute of Industrial Technology, Siheung 15014, Korea;Department of Industry-University Convergence, Hanbat National University, Yuseong, Daejeon 34158, Korea;Department of Mechanical Engineering, Incheon National University, Yeonsu, Incheon 22012, Korea;HYU-KITECH Joint Department, Hanyang University, Ansan 15588, Korea;

关键词: 17-4 PH stainless steel;    selective laser melting;    laser powder bed fusion;    heat treatment;    microstructure;    mechanical properties;   

DOI  :  10.3390/met12050704

来源: DOAJ

【 摘 要 】

Laser powder bed fusion (L-PBF)-processed 17-4 PH stainless steel (SS) generally exhibits a non-equilibrium microstructure consisting mostly of columnar δ-ferrite grains and a substantial fraction of retained austenite and martensite, contrary to 17-4 PH SS wrought with a fully martensite structure and coarse grains. Despite the different microstructures of L-PBF and wrought 17-4 PH SS, post-processing is typically performed using the conventional heat treatment method. The insufficient effect of the heat treatment on the L-PBF product produces a δ-ferrite phase in the microstructure. To obtain improved mechanical properties, the addition of a normalizing treatment to the conventional heat treatment after L-PBF in a nitrogen gas environment was investigated. The fully martensitic matrix developed by adding the normalizing treatment contained homogeneous Cu precipitates and exhibited a similar or improved strength and elongation to failure compared to the wrought SS.

【 授权许可】

Unknown