Influence of High-Frequency Micro-Forging on Microstructure and Properties of 304 Stainless Steel Fabricated by Laser Rapid Prototyping

2013 ◽  
Vol 84 (9) ◽  
pp. 870-877 ◽  
Author(s):  
Yan Zhang ◽  
Chang Jun Qiu ◽  
Yong Chen ◽  
Jinshui Yu ◽  
Ju Zhou ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Rapid Prototyping ◽  
High Frequency ◽  
304 Stainless Steel ◽  
Microstructure And Properties

Microstructure and Properties of 304 Stainless Steel Specimen Manufactured by Cold Metal Transfer + Pulse Composite Arc Additive

2021 ◽  
Vol 13 (1) ◽  
pp. 152-160
Author(s):  
Yanjie Wang ◽  
Xuru Hou ◽  
Lin Zhao ◽  
Yun Peng ◽  
Chengyong Ma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Fracture Surface ◽  
Steel Specimen ◽  
Corrosion Current ◽  
Electrochemical Analysis ◽  
304 Stainless Steel ◽  
Cold Metal Transfer ◽  
Σ Phase ◽  
Microstructure And Properties

304 stainless steel test block was fabricated by continuous melting wire with CMT and pulse mixed mode, and the path of additive manufacturing is layered slice S-shaped. The relationship between microstructure and properties of the specimen was investigated by microscope, SEM, EBSD, XRD, tensile, impact and electrochemical experiments. The results show that molding between weld and weld is very good, and the microstructure is mainly Austenite, Ferrite and a little of σ, and there are three kinds of Ferrite morphology: cellular, wormlike and lath. σ phase precipitates easily in regions with high ferrite content and is distributed at the boundary between austenite and ferrite. The specimen has good low temperature toughness. The microscopic fracture surface is mainly dimple, and the precipitates in the fracture surface are mainly fine carbide particles. The tensile strength of the additive manufacturing 304 specimen is higher than the forged specimen, and the type of fracture is ductile fracture. The electrochemical analysis of 304 stainless steel specimens and forgings shows that CMT and pulse arc additive manufacturing specimen has excellent corrosion resistance and its corrosion current is slightly lower than the forging.

Research on Acoustic Emission Signals Characteristics of Pitting Corrosion on 304 Stainless Steel

2013 ◽  
Author(s):  
Zhongzheng Zhang ◽  
Hua Liang ◽  
Cheng Ye ◽  
Wensheng Cai ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Pitting Corrosion ◽  
High Frequency ◽  
Low Frequency ◽  
Ferric Chloride Solution ◽  
304 Stainless Steel ◽  
Flexural Wave ◽  
Higher Temperature ◽  
Ae Signals

In order to study acoustic emission (AE) signals waveform characteristics of pitting corrosion on 304 stainless steel under higher temperature than lower one, Pitting corrosion process on 304 stainless steel in 6% ferric chloride solution at 70°C was monitored by AE technology. Wavelet transform and mode acoustic emission technology were combined to deal with recorded AE signals, and micromorphologic observation was performed for further verification. The results showed that signal waveform was mainly composed of low-frequency (<100KHz) flexural wave with larger amplitude & energy and high-frequency (>100KHz) expansion wave with lesser amplitude & energy. The research results have some certain significance for AE monitoring of pitting corrosion on 304 stainless steel.

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