Influence of annealing treatment on the microstructure and mechanical performance of cold sprayed 304 stainless steel coating

Results of study on the laser welding process of pillow plates heat exchangers are presented in the article. The influence of basic parameters of CO2laser welding on the quality of overlap joints of AISI 304 stainless steel plates 2.0 and 4.0 mm thick was determined. The range of optimal parameters of welding, providing the highest quality and high mechanical performance of the test joints was determined. The technological conditions elaborated during the study were applied for manufacturing of the real pillow plates heat exchangers with dimensions of 1.5 x 1.5 m.

Download Full-text

Superior Strength and Ductility of 304 Austenitic Stainless Steel with Gradient Dislocations

Nanomaterials ◽

10.3390/nano11102613 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2613

Author(s):

Qingsong Pan ◽

Song Guo ◽

Fang Cui ◽

Lijun Jing ◽

Lei Lu

Keyword(s):

Stainless Steel ◽

Mechanical Performance ◽

Uniform Elongation ◽

Deformation Mechanisms ◽

Coarse Grained ◽

304 Stainless Steel ◽

Deformation Twins ◽

304 Austenitic Stainless Steel ◽

Multiple Deformation ◽

Strength And Ductility

Materials with designed gradient nanograins exhibit unprecedented mechanical properties, such as superior strength and ductility. In this study, a heterostructured 304 stainless steel with solely gradient dislocation structure (GDS) in micron-sized grains produced by cyclic-torsion processing was demonstrated to exhibit a substantially improved yield strength with slightly reduced uniform elongation, compared with its coarse grained counterparts. Microstructural observations reveal that multiple deformation mechanisms, associated with the formation of dense dislocation patterns, deformation twins and martensitic phase, are activated upon straining and contribute to the delocalized plastic deformation and the superior mechanical performance of the GDS 304 stainless steel.

Download Full-text

Microstructure and mechanical performance of dissimilar metal joints of aluminium alloy and stainless steel by cutting-assisted welding-brazing

10.21203/rs.3.rs-844889/v1 ◽

2021 ◽

Author(s):

Huibin Xu ◽

Wei Cong ◽

Donghua Yang ◽

Yanlong Ma ◽

Wanliang Zhong ◽

...

Keyword(s):

Stainless Steel ◽

Aluminium Alloy ◽

Cutting Tool ◽

Mechanical Performance ◽

Interfacial Structure ◽

304 Stainless Steel ◽

Small Scale ◽

Joint Interface ◽

Micro Scale ◽

Macro Scale

Abstract The 5052 aluminium alloy and 304 stainless steel were successfully joined by cutting-assisted welding-brazing (CAWB) method without using flux. Dual-scale interfacial structures were achieved by manipulating the cutting tool profile. Results indicated that the macro-scale interfacial structure was produced at the joint interface when the taper step-shape cutting tool was adopted. As the cutting tool step was increased to 6-step, the micro-scale interface took on serrated morphology and a layer of continuous and wavy intermetallic compound (IMC) with an average thickness of 3.3 μm was formed at the interface. The τ 4 IMC particles and the FeAl 6 phases on a small scale were dispersed homogeneously in the welded seam. The maximum tensile strength of the joints reached 152.3 MPa upon tensile loading, 75% that of the 5052 aluminium base metal. The strong and reliable Al/steel dissimilar joints were attributed to the particle reinforced weld metal and the macro- and micro-scale dual self-locking structure at the interface.

Download Full-text

Sensitization of an austenitic stainless steel due to the occurrence of δ-ferrite

Corrosion Reviews ◽

10.1515/corrrev-2018-0036 ◽

2019 ◽

Vol 37 (2) ◽

pp. 179-186 ◽

Cited By ~ 1

Author(s):

Carlos R. Arganis-Juárez ◽

Audi Vázquez ◽

Nelson F. Garza-Montes-de-Oca ◽

Rafael Colás

Keyword(s):

Stainless Steel ◽

Annealing Treatment ◽

304 Stainless Steel ◽

Solution Temperature ◽

Force Microscopy ◽

Ferrite Number ◽

Δ Ferrite ◽

Phase Images ◽

Degree Of Sensitization ◽

High Degree

AbstractA series of analyses were conducted on samples of an austenitic type 304 stainless steel that exhibited a high degree of sensitization (DOS) after being subjected to a solution annealing treatment at 1050°C. The DOS was detected by electrochemical potentiokinetic tests. Examination by scanning electron microscopy of etched samples revealed the presence of δ-ferrite within the austenitic matrix, and of the segregation of chromium and nickel in either phase; images obtained by atomic force microscopy revealed localized attack at the austenite/δ-ferrite interface. It was found that the DOS and the ferrite number of the steel were reduced as the material was held at the solution temperature for longer times. Aging at 650°C showed precipitation of chromium carbides at grain boundaries and at the austenite/δ-ferrite interface; this treatment increased the DOS.

Download Full-text