The effect of coordinated deformation on the microstructure and corrosion performance of 316L stainless steel/20# carbon steel composite pipes during hot compression

• Published in: Materials letters 2024-12, Vol.377, p.137374, Article 137374
• Main Authors: Guo, Meitong, Gao, Zhiming, Song, Junlin, Liu, Zhihong, Wu, Zhong, Lv, Chuantao, Hu, Wenbin
• Format: Article
• Language: English
• Subjects: Corrosion; Crystal structure; Recrystallization
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2024.137374

[Display omitted] •Higher hot compression temperature decrease critical strain for recrystallization.•Coordinated deformation of 20# in composite pipe reduces 316 recrystallization.•Increasing hot compression temperature and 316L thickness refine grain structure.•Grain refinement and microstructural homogenization enhance corrosion resistance. Through hot compression experiments under different deformation conditions (0.1 s−1 at 900 °C/1050 °C/1200 °C), the effect of coordinated deformation on microstructure evolution was studied, and the influence of different initial microstructures on corrosion performance was subsequently investigated. As a result, strain preferentially concentrated in 20#, resulting in dynamic recrystallization (DRX). Subsequently, grain refinement and DRX occurred in 316L. Additionally, the farther from the interface, the weaker the coordinated deformation effect. Compared to only 316L, the 316L in composite pipes has higher density of dislocations and low-angle grain boundaries. Corrosion resistance is related to the microstructure after coordinated deformation, decreasing with the increase in dislocation density, low-angle grain boundaries, and recrystallized grain size. At 1200 °C, the effect of coordinated deformation on 316L is significantly reduced. The passivation film resistance is 2.14 × 106 Ω·cm2, similar to that of only 316L. Therefore, appropriately increasing the hot rolling temperature and the thickness of 316L in the billet can reduce the effect of coordinated deformation on the DRX of 316L, thereby maintaining the pitting corrosion resistance of 316L.