Applications of Wrought Austenitic Stainless Steel Corrosion Testing to Laser Powder Bed Fusion 316L

CORROSION ◽  
10.5006/3885 ◽  
2021 ◽  
Author(s):  
Duane Macatangay ◽  
Jenna Conrades ◽  
Keegan Brunner ◽  
Robert Kelly

Recent developments in the 3-D printing of austenitic stainless steels have led to the need for standardization of electrochemical techniques used to assess the corrosion performance of these alloys. Currently, ASTM standards for austenitic stainless focus on assessing their resistance to different modes of corrosion such as pitting, crevice, and intergranular corrosion. Due to the complexity of the additive process, selective corrosion occurs in microstructural features such as cellular structures and melt pool boundaries. Standardized corrosion testing needs to incorporate these microstructural features. This study characterizes the corrosion behavior of LPBF stainless steel in a variety of ASTM standards with special attention to melt pool boundary dissolution, cellular structures, and intergranular corrosion.

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  

Abstract CarTech 347 is a niobium+tantalum stabilized austenitic stainless steel. Like Type 321 austenitic stainless steel, it has superior intergranular corrosion resistance as compared to typical 18-8 austenitic stainless steels. Since niobium and tantalum have stronger affinity for carbon than chromium, carbides of those elements tend to precipitate randomly within the grains instead of forming continuous patterns at the grain boundaries. CarTech 347 should be considered for applications requiring intermittent heating between 425 and 900 °C (800 and 1650 °F). This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1339. Producer or source: Carpenter Technology Corporation.


2019 ◽  
Vol 66 (6) ◽  
pp. 774-781 ◽  
Author(s):  
Jeetendra Kumar Malav ◽  
Ramesh C. Rathod ◽  
Vipin Tandon ◽  
Awanikumar P. Patil

Purpose The purpose of this study is to improve the anticorrosion performance of low nickel stainless steel (AISI 201) in 3.5% NaCl by electroactive polyimide/copper oxide (EPI/CuO) composites coating. Design/methodology/approach Electroactive polyimide/copper oxide (EPI/CuO) composites were prepared by oxidative coupling polymerization followed by thermal imidization method. Findings The functional and structural properties of composites were characterized by X-ray diffraction, Fourier transmission infra-red and ultra violet-visible spectroscopy and the surface topography was characterized by field emission scanning electron microscope analysis and anticorrosion performance in 3.5 Wt.% NaCl was evaluated by electrochemical techniques. The obtained results of electrochemical techniques measurement indicated that the composites coated samples give better corrosion protection against attacking electrolyte. Originality/value The ever-increasing price of nickel (Ni) is driving the industries to use low-Ni austenitic stainless steels (ASSs). However, it exhibits relatively poor corrosion resistance as compared with conventional Cr-Ni ASSs. Nonetheless, its corrosion resistance can be enhanced by polymeric (electroactive polyimide [EPI]) coating. CuO particles exhibit the hydrophobic properties and can be used as inorganic filler to incorporate in EPI to further enhance the corrosion protection. The present research paper is beneficial for industries to use low-cost AISI 201, enhance its corrosion resistance and replace the use of costly conventional Cr-Ni ASSs.


2019 ◽  
Vol 1 (1) ◽  
pp. 425-432
Author(s):  
Tomasz Lipiński ◽  
Dariusz Karpisz

Abstract Austenitic stainless steels are often used for a materials in the construction of machines and equipment for agricultural and for industrial construction. One of the most important factors constructional material is corrosion resistance. Equipment with austenitic stainless steel can be easy join by quickly welding at a not to high construction price, but one with the serious problem in aggressive environment is their corrosion resistance. A few corrosion processes in crevices and awkward corners can be avoided at the design stage (low roughness parameters, round-section and other). But still the construction material is exposed to corrosion. These steels often come into contact with an aggressive environment based on nitric acid. The main aim of this research is to investigate corrosion resistance in different time (48, 96, 144, 192, 240, 288, 336 hours). For this used weight loss of test samples and its profile roughness. The research was conducted on austenitic stainless steel in grade in Nitrate acid at 333 K. Corrosion tests confirmed that the research this steel in 65% nitrate acid as a corrosive environments is characterized through proportionate to time corrosion process whose measure may be surface roughness. In industrial practice roughness parameters for all the research times can be used for determine the stage and size of steel corrosion.


Author(s):  
D. N. Wasnik ◽  
V. Kain ◽  
I. Samajdar

Grain boundaries play a very important role in intergranular corrosion. They determine whether the material is prone to intergranular corrosion or not. A study has been carried out to determine the influence of grain boundaries on the degree sensitization of Type 304 stainless steel (SS) and Type 316L stainless steel. The alloys were different thermomechanical treatment to obtain a variation in grain boundaries. They were then annealed and sensitized. The degree of sensitization was evaluated by using the Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) technique and intergranular corrosion was evaluated by ferric sulfate-sulfuric acid test. In these tests, the degree of sensitization was measured by determining the ratio of the maximum current generated by a reactivation scan to that of the anodic scan, i.e. Ir: Ia, and intergranular corrosion was measured from weight loss of specimens. The grain boundary character distribution was measured with the help of Orientation Imaging Microscope (OIM). The degree of sensitization was then related to the grain boundary measurements. It was found that the degree of sensitization and intergranular corrosion is low at high angle grain boundaries in both types of stainless steel.


2013 ◽  
Vol 794 ◽  
pp. 517-529 ◽  
Author(s):  
Vivekanand Kain ◽  
Shagufta Khan ◽  
A.V.R. Reddy ◽  
P.K. Wattal

The austenitic stainless steels are used in nuclear spent fuel reprocessing and waste management plants and the process fluid is nitric acid at temperature up to boiling point. However incorporation of oxidizing ions e.g. fission products as well as corrosion products, in nitric acid stream make the environment highly corrosive to stainless steels. Present work aims to investigate role of process parameters and material parameters (composition and microstructure) on corrosion behaviour of stainless steels. The process parameters studied are temperature, acid concentration and oxidizing ions. It has been shown that the potential attained on stainless steel is a function of acid concentration and temperature and is further strongly affected by addition of oxidizing ions. This developed potential determines the corrosion behaviour of stainless steel. Increasing the temperature and concentration of nitric acid and concentration of oxidizing species increased the developed potential. Potentials were applied to types 304 L (nitric acid grade - NAG), 304 L (commercial purity) and 310 L stainless steels in boiling 6 M nitric acid for a period of 48 h. The corrosion rates measured in such experiments were plotted as a function of applied potential. The form of corrosion was established by microstructural examination. A clear demarcation was observed between uniform corrosion and intergranular corrosion at a potential of 960-980 mVSCE. Above this potential range corrosion rate increased exponentially and the form of corrosion is shown to be intergranular corrosion. Below this potential range, uniform and low rate of corrosion occurred. The influence of microstructure (step, dual and ditch) of type 304 L was also studied and is described in this paper.


2012 ◽  
Vol 1372 ◽  
Author(s):  
R. Galvan-Martinez ◽  
M. Flores-Cocuyo ◽  
R. Orozco-Cruz ◽  
A. Contreras

ABSTRACTAn electrochemical study was carried out in order to obtain the effects of the turbulent flow condition on the stainless steel corrosion immersed in natural seawater using an electrochemical corrosion technique like electrochemical impedance spectroscopy (EIS). A three-electrode electrochemical glass cell was used to obtain the electrochemical measures, where a cylinder of the AISI 410 stainless steel was used as working electrode, a saturated calomel electrode as reference electrode and a synthesised graphite rod as auxiliary electrode. 24 hours was the total exposure time. In order to control the hydrodynamic conditions a rotating cylinder electrode (RCE) was used and, a scanning electron microscope (SEM) was used in order to obtain the superficial analyses of the metallic surface after tests. The results of the electrochemical techniques shown that at 1000 rpm of the rotation speed, the corrosion rate (CR) increased as the exposure time also increased. In additions, in the other rotations speed (2000, 3000 and 5000 rpm), the CR was affected by the corrosion products formed on metallic surface. t is important to point out that the corrosion morphology found in the steel sample was localized corrosion.


Author(s):  
Ikuo Ioka ◽  
Chiaki Kato ◽  
Kiyoshi Kiuchi ◽  
Junpei Nakayama

Austenitic stainless steels suffer intergranular attack in boiling nitric acid with oxidants. The intergranular corrosion is mainly caused by the segregation of impurities to grain. An extra high purity austenitic stainless steel (EHP alloys) was developed with conducting the new multiple refined melting technique in order to suppress the total harmful impurities less than 100ppm. The basically corrosion behavior of type 310 EHP alloy with respect to nitric acid solution with highly oxidizing ions was investigated. The straining, aging and recrystallizing (SAR) treated type 310 EHP alloy showed superior corrosion resistance for intergranular attack. The segregated boron along the grain boundaries was one of main factor of intergranular corrosion from fission track etching results. The SAR treatment was effective to restrain the intergranular attack for type 310 EHP alloy with B less than 7ppm.


Author(s):  
R. Gonzalez ◽  
L. Bru

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.


Author(s):  
Ya.G. Avdeev ◽  
◽  
Yu.B. Makarychev ◽  
D.S. Kuznetsov ◽  
L.P. Kazanskii ◽  
...  

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