scholarly journals Effect of Processing Conditions on the Microstructure, Mechanical Properties, and Corrosion Behavior of Two Austenitic Stainless Steels for Bioimplant Applications

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1311
Author(s):  
Mariana-Beatriz R. Silva ◽  
Virgine Roche ◽  
Telma M. Blanco ◽  
Nguyen Hoang Viet ◽  
Oscar Balancin ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Thermomechanical Processing ◽  
Austenitic Stainless Steels ◽  
Recovery Process ◽  
Solute Drag ◽  
Processing Parameters ◽  
Austenitic Steels ◽  
Processing Times ◽  
General Terms ◽  
Hot Torsion

Hot torsion tests were carried out to simulate the industrial thermomechanical processing of two austenitic steels for bioimplant applications, namely ISO 5832-9 and ASTM F138. The former has Ti, Nb, and V in the composition, being N-rich. However, the latter is Ni-richer and without extra alloying element additions. Special attention was paid to the effect of interpass times, particularly to the soaking temperature, which was reduced to decrease processing times and costs. Optical and electron microscopy, corrosion tests, and hardness measurements were used to characterize the effect of the above processing parameters on both alloys. No significant increase in processing loads was noticed after the reduction of the reheating temperature. This was explained in terms of the balance between partial particles dissolution and the increment in the solute drag effect provided by the elements put into solution. Such an increment in solid solution favored the dynamic recovery process, delaying the dynamic recrystallization one. However, strain-induced precipitation took place at lower temperatures, by using the extra N and Cr delivered to the matrix, and limiting the recrystallization softening. The rolling schedule promoted abundant grain refinement. The final grain size ranged from 2.5 to 11 µm, depending on reheating temperature, interpass time, presence of alloying elements, and N. In general terms, the corrosion resistance of the ISO steel soaked at the lowest temperature (1200 °C) was better than when reheated to the highest one (1250 °C). On the contrary, the F138 steel had worse corrosion behavior.

scholarly journals Machine learning augmented predictive and generative model for rupture life in ferritic and austenitic steels

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Osman Mamun ◽  
Madison Wenzlick ◽  
Arun Sathanur ◽  
Jeffrey Hawk ◽  
Ram Devanathan
Keyword(s):  
Pearson Correlation ◽  
Rupture Life ◽  
Model Performance ◽  
Austenitic Stainless Steels ◽  
Generative Model ◽  
Austenitic Steels ◽  
Gradient Boosting ◽  
Variational Autoencoder ◽  
Feature Importance ◽  
Boosting Algorithm

AbstractThe Larson–Miller parameter (LMP) offers an efficient and fast scheme to estimate the creep rupture life of alloy materials for high-temperature applications; however, poor generalizability and dependence on the constant C often result in sub-optimal performance. In this work, we show that the direct rupture life parameterization without intermediate LMP parameterization, using a gradient boosting algorithm, can be used to train ML models for very accurate prediction of rupture life in a variety of alloys (Pearson correlation coefficient >0.9 for 9–12% Cr and >0.8 for austenitic stainless steels). In addition, the Shapley value was used to quantify feature importance, making the model interpretable by identifying the effect of various features on the model performance. Finally, a variational autoencoder-based generative model was built by conditioning on the experimental dataset to sample hypothetical synthetic candidate alloys from the learnt joint distribution not existing in both 9–12% Cr ferritic–martensitic alloys and austenitic stainless steel datasets.

scholarly journals Crevice Corrosion Behavior of Nitrogen Bearing Austenitic Stainless Steels

1999 ◽  
Vol 48 (3) ◽  
pp. 169-175 ◽  
Author(s):  
Alberto A. Ono ◽  
Tadashi Shinohara ◽  
Shigeo Tsujikawa
Keyword(s):  
Corrosion Behavior ◽  
Stainless Steels ◽  
Crevice Corrosion ◽  
Austenitic Stainless Steels

Effect of recrystallization on degree of sensitization in nickel free austenitic stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sourabh Shukla ◽  
Awanikumar P. Patil ◽  
Ashlesha Kawale ◽  
Anand Babu Kotta ◽  
Inayat Ullah
Keyword(s):  
Stainless Steel ◽  
Thermal Aging ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
Austenitic Stainless Steels ◽  
Content Type ◽  
High Deformation ◽  
Strain Induced Martensite ◽  
Degree Of Sensitization ◽  
Cold Worked

Purpose Effect of grain size on degree of sensitization (DOS) was been evaluated in Nickel free steel. Manganese and nitrogen contained alloy is a Ni-free austenitic stainless steels (ASS) having type 202 grade. The main purpose of this investigation is to find the effect of recrystallization on the DOS of stainless steel after the thermo-mechanical processing (cold work and thermal aging). Design/methodology/approach In the present investigation, the deformation of 202 grade analyzed using X-ray diffraction (XRD) and microstructural testing. Optical microstructure of Ni-free ASS has been done for cold worked samples with thermally aged at 900°C_6 h. Double loop electrochemical potentiodynamic reactivation test used for findings of degree of sensitization. Findings Ni-free ASS appears to be deformed more rapidly due to its higher stacking fault energy which gave results in rapid transformation from strain induced martensite to austenite in form of recrystallized grains, i.e. it concluded that as cold work percentage increases more rapidly recrystallization occurs. XRD results also indicate that more fraction of martensite formed as percentage of CW increases but as thermal aging reverted those all martensite to austenite. So investigation gives the conclusion which suggests that with high deformation at higher temperature and duration gives very less DOS. Originality/value Various literatures available for 300 series steel related to the effect of cold work on mechanical properties and sensitization mechanism. However, no one has investigated the effect of recrystallization through thermomechanical processing on the sensitization of nickel-free steel.

scholarly journals Analysis of Recrystallization and Strain-Induced Precipitation on High Nb- and N-Bearing Austenitic Stainless Steel

2014 ◽  
Vol 922 ◽  
pp. 700-705 ◽  
Author(s):  
Mariana B.R. Silva ◽  
J. Gallego ◽  
Jose María Cabrera ◽  
O. Balancin ◽  
Alberto Moreira Jorge
Keyword(s):  
Thermomechanical Processing ◽  
Extraction Replica ◽  
Carbon Extraction Replica ◽  
Thin Foils ◽  
Transmission Electron ◽  
Hot Torsion ◽  
Deformation Pass ◽  
Mechanical Properties And Corrosion ◽  
Multiple Deformation ◽  
Soaking Temperature

The mechanical properties and corrosion resistance of stainless steels are due to the combined effect of chemical composition and thermomechanical processing. The objective of this study was to investigate the interaction precipitation-recrystallization of an austenitic steel with high additions of nitrogen and niobium through continuous-cooling multiple deformation hot-torsion tests. Samples were heated up to a soaking temperature of 1250oC and kept at this temperature for 5 minutes, and then deformed during cooling. The deformation pass was 0.3 with a strain rate of 1 s-1and interpass times of 20 or 50 s. The evolution of the microstructure was investigated by optical, EBSD and transmission electron microscopy, using thin foils and carbon extraction replica samples. The results showed that some precipitates were not dissolved after reheating and the presence of niobium-and chromium-rich particles after processing was confirmed. The strain accumulation with the interpass time of 20 s yielded finer precipitation and improved grain refinement than observed after 50 s. Some interaction of the precipitates with dislocations and grain boundary could be evidenced.

The Effect of Water Pressure Variation on Cut Surfaces Quality during Abrasive Waterjet Cutting of Austenitic Steels

2014 ◽  
Vol 1029 ◽  
pp. 176-181 ◽  
Author(s):  
Ion Aurel Perianu ◽  
Ion Mitelea ◽  
Viorel Aurel Şerban
Keyword(s):  
Water Pressure ◽  
Austenitic Stainless Steels ◽  
Water Jet ◽  
Pressure Variation ◽  
Austenitic Steels ◽  
Abrasive Waterjet ◽  
Abrasive Water Jet ◽  
Effect Of Water ◽  
Water Jet Cutting ◽  
Abrasive Water Jet Cutting

In this paper research elements regarding the effect of water pressure variation on cut surfaces quality are presented in the field of abrasive water jet cutting of materials hard to process by machining such as austenitic stainless steels, in this case with a thickness of 20 mm. Selection of the optimal cutting process based on technical and economic criteria takes into consideration the type and thickness of the targeted material and also the physical and geometrical quality requirements. The present paper contains experimental research results regarding abrasive water jet cutting of austenitic stainless steel EN 1.4306 (ASTM 304 L) at different values of water pressure. The abrasive material used is Garnet with particle granulation 80 Mesh. By making roughness measurements and hardness examinations of the cut surface an evaluation will be made of the surface quality defining the optimal pressure values.

Microstructural evolution and corrosion behavior of Sanicro 28 during thermomechanical processing

2020 ◽  
Vol 24 ◽  
pp. 101228
Author(s):  
Niloofar Eftekhari ◽  
Waqas Muhammad ◽  
Farahnaz Haftlang ◽  
Abbas Zarei-Hanzaki ◽  
Étienne Martin
Keyword(s):  
Corrosion Behavior ◽  
Microstructural Evolution ◽  
Thermomechanical Processing ◽  
Sanicro 28

Conversaziones and Receptions, 1964

1964 ◽  
Vol 19 (2) ◽  
pp. 113-118
Keyword(s):  
Austenitic Stainless Steels ◽  
Austenitic Steels ◽  
Research Association ◽  
Cavendish Laboratory ◽  
Iron And Steel ◽  
Partial Dislocations ◽  
Steel Research ◽  
Metallurgy Department ◽  
Dislocation Movement ◽  
The Subject

THE conversazione held on 9 July to mark the quater-centenary of the birth of Galileo is described on page 119. The usual conversaziones were held on 7 May and 22 October at which the following exhibits were shown. The strength and fracture of metals was the subject of three exhibits. It is known that the strength of metals is far below its theoretical limit due to the presence of dislocations in the crystal structure. All strengthening processes introduce barriers to dislocation movement but many of these reduce ductility and make metals brittle. The British Iron and Steel Research Association demonstrated how modern physical metallurgical research is indicating new ways in which steel can be strengthened without impairment of ductility or toughness. Miss J. M. Silcock of the Central Electricity Research Laboratories and Mr W. J. Tunstall of the Cavendish Laboratory arranged an exhibit showing stacking fault precipitation in austenitic stainless steels. Electron microscopy has shown that stacking faults appear and grow during the precipitation of carbides in certain austenitic steels. Systematic observations coupled with new calculations have established the nature of the associated partial dislocations and have led to the conclusion that the faults are extrinsic. The Chemistry, Physics and Metallurgy Department of the Royal Aircraft Establishment arranged an exhibit on the fracture of metals. Various forms of fracture were exhibited and research observations and tentative conclusions of the causes of fracture were made known.

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