Stress corrosion cracking b ehavior of 316 L manufacture d by different additive manufacturing techniques in hydrofluoric acid vapor  

作　　者：Hailong Dai Shuyao Zhang Yajing Li Jingtai Yu Yue Kuang Fuzhen Xuan Xu Chen 

机构地区：[1]School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China [2]Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology,Tianjin 300350,China [3]School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Journal of Materials Science & Technology》2024年第24期33-48,共16页材料科学技术(英文版)

基　　金：partially supported by the National Key Research and Development Program of China(Nos.2022YFC3004500,2018YFC0808600);the Ningbo Natural Science Foundation(No.2021J006);the China Postdoctoral Science Foundation(No.2023TQ0113);the Shanghai Pujiang Programme(No.23PJD022).

摘　　要：Selective laser melting(SLM)and directed energy deposition(DED),as two important additive manufacturing(AM)methods,have garnered widespread industrial applications attributing to their advantages in fabricating complex structures.Since the complex nature of microstructures produced by different AM technologies,it is necessary to carry out a thorough investigation of the stress corrosion cracking(SCC)behavior affected by these microstructures in harsh environments(i.e.hydrofluoric acid(HF)).In this study,the SCC susceptibility of DED and SLM-fabricated 316 L in HF vapor was first systematically studied by comparing it with commercial wrought(WR)316 L to reveal the effect of microstructures(columnar crystals,melt pools,δ-ferrites,and dislocation cells)on the SCC behavior.Results show that DED-316 L has excellent SCC resistance and such resistance exhibits a low correlation with loading direction.This is because the reticulated distributed skeletal δ-ferrite facilitates enhancing film protection and hindering dislocation slip transfer.In contrast,SLM-316 L exhibits high SCC sensitivity together with a strong loading direction correlation.An SLM-316L-V with melt pool boundaries oriented perpendicular to the stress exhibits a high SCC tendency.Moreover,the dislocation cells without elemental segregation in SLM-316 L activate the corrosion reactivity and favor dislocation proliferation and transport,making SCC deterioration of SLM-316L-V in HF vapor.While a proper loading relationship can shield the adverse effect of dislocation cells on the stress corrosion of SLM-316 L(e.g.SLM-316L-H).Our effort s provide import ant theoretical guidance for the rational selection of fabrication technologies and microstructural design of materials in harsh environments.

关 键 词：316 L Selective laser melting Directed energy deposition Stress corrosion cracking Dislocation cell 

分 类 号：TB383.3[一般工业技术—材料科学与工程]