Microstructure and Solute Segregation around the Melt-Pool Boundary of Orientation-Controlled 316L Austenitic Stainless Steel Produced by Laser Powder Bed Fusion

被引：12

作者：

Sato, Kazuhisa ^{[1
]}

Takagi, Shunya ^{[1
]}

Ichikawa, Satoshi ^{[1
]}

Ishimoto, Takuya ^{[2
,3
,4
]}

Nakano, Takayoshi ^{[2
,3
]}

机构：

[1] Osaka Univ, Res Ctr Ultrahigh Voltage Electron Microscopy, 7-1 Mihogaoka, Ibaraki 5670047, Japan

[2] Osaka Univ, Grad Sch Engn, Div Mat & Mfg Sci, 2-1 Yamadaoka, Suita 5650871, Japan

[3] Osaka Univ, Anisotrop Design & Addit Mfg Res Ctr, 2-1 Yamadaoka, Suita 5650871, Japan

[4] Univ Toyama, Aluminium Res Ctr, 3190 Gofuku, Toyama 9308555, Japan

来源：

MATERIALS | 2023年 / 16卷 / 01期

关键词：

additive manufacturing; laser powder-bed fusion; cellular microstructure; solidification segregation; transmission electron microscopy; CORROSION;

D O I：

10.3390/ma16010218

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

For this article, we studied the microstructure and solute segregation seen around the melt pool boundary of orientation-controlled 316L austenitic stainless steel produced by laser powder bed fusion, using transmission electron microscopy and energy-dispersive x-ray spectroscopy. We found that the solidification cellular microstructures could be visualized with the aid of solute segregation (Cr and Mo) during solidification. Mn-Si-O inclusions (10-15 nm in diameter) were distributed along the lamellar boundaries, as well as in the dislocation cell walls. It is believed that the grain growth of the inclusions can be effectively suppressed by rapid quenching during the laser powder-bed fusion process. A thin region without cellular microstructures was observed at the melt-pool boundary. The cellular spacing widened near the bottom of the melt-pool boundary, owing to the decrease in the cooling rate. Atomic-structure analysis at the lamellar boundary by high-resolution transmission electron microscopy revealed a local interfacial structure, which is complementary to the results of electron back-scatter diffraction.

引用

页数：10