Heat Treatments to Desensitize and Remove Delta Ferrite from a 21Cr-6Ni-9Mn Stainless Steel Intended for the Fabrication of Aerofoil Models for Cryogenic Wind Tunnels

Author(s):  
D. A. Wigley
2013 ◽  
Vol 773-774 ◽  
pp. 785-794
Author(s):  
Amir Mahmoudi ◽  
Mohammad Esmailian ◽  
Seyed Eshagh Aghamiri

In this investigation, AISI321 steel was solution - stabilizing post heat treated in various temperatures and times after SMAW welding. Results show, increasing of temperature in solution and stabilizing heat treatment, raise sensitization; in addition, by increasing of the solution heat treatment time, sensitization enhances. However, increasing the time of stabilizing heat treatment creates less chrome carbides, so the sensitization decreases. These heat treatments reduce the amount of delta ferrite and change its morphology from narrow and acicular shape to discontinues and separate globular particles. Moreover, more carbide and carbonitrid of Ti and Nb are also created.


2016 ◽  
Vol 58 (6) ◽  
pp. 489-494 ◽  
Author(s):  
Panyasak Phakpeetinan ◽  
Amnuysak Chianpairot ◽  
Ekkarut Viyanit ◽  
Fritz Hartung ◽  
Gobboon Lothongkum

Alloy Digest ◽  
1991 ◽  
Vol 40 (8) ◽  

Abstract LESCALLOY 15-5 VAC-ARC is a precipitation hardening martensitic stainless steel with minimal delta ferrite. Vacuum arc remelting in the production of the alloy provides a low gas content, clean steel with optimum transverse properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-522. Producer or source: Latrobe Steel Company.


2018 ◽  
Vol 7 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Cesar G. Camerini ◽  
Vitor Manoel A. Silva ◽  
Iane A. Soares ◽  
Rafael Wagner F. Santos ◽  
Julio Endress Ramos ◽  
...  

2012 ◽  
Vol 159 ◽  
pp. 346-350
Author(s):  
Shu Min Liu ◽  
Jian Bin Zhang

The elevated temperature short-time tensile test with the sample of casting low nickel stainless steel was conducted on SHIMADZU AG-10 at ten temperatures 300, 500, 600, 700, 800, 950, 1000, 1050, 1100, and 1250°C, respectively. The stress-strain curves with the thermal deformation at the different temperatures, the peak stress intensity-temperature curve, and the reduction percentage of cross sectional area-temperature curve were obtained. Metallographic test samples were prepared and the morphology of deforming zone was observed by optical microscopy. The experimental results show that the tensile strength of the test samples decreases with increasing temperature. From 300 to 800°C, the work harding occurred and the tensile strength increases with increasing strain. The work softening occurred and the tensile strength decreases with increasing strain at temperatures of 800 to 1250°C. The minimum value of reduction percentage was measured at 800 °C. The austenite and delta-ferrite are the main phase in the tested samples. When the tensile temperatures are increased to 1200°C, the delta-ferrite became thinner and broke down to be spheroidized.


1964 ◽  
Vol 50 (10) ◽  
pp. 1509-1511
Author(s):  
Tadamichi TAKEI ◽  
Haruo SHIMADA

2022 ◽  
Vol 60 (1) ◽  
pp. 46-52
Author(s):  
Young Woo Seo ◽  
Chan Yang Kim ◽  
Bo Kyung Seo ◽  
Won Sub Chung

This study evaluated changes in delta-ferrite content depending on the preheating of AISI 316L stainless steel. We also determined the reasons for the variation in delta-ferrite content, which affects corrosion resistance. Changes in delta-ferrite content after preheating was confirmed using a Feritscope, and the microstructure was analyzed using optical microscopy (OM). We found that the delta-ferrite microstructure size decreased when preheating time was increased at 1295 oC, and that the delta-ferrite content could be controlled through preheating. Potentiodynamic polarization test were carried out in NaCl (0.5 M) + H2SO4 (0.5 M) solution, and it was found that higher delta-ferrite content resulted in less corrosion potential and passive potential. To determine the cause, an analysis was conducted using energy-dispersive spectroscopy (EDS), which confirmed that higher delta-ferrite content led to weaker corrosion resistance, due to Cr degradation at the delta-ferrite and austenite boundaries. The degradation of Cr on the boundaries between austenite and delta-ferrite can be explained by the difference in the diffusion coefficient of Cr in the ferrite and austenite. A scanning electron microscopy (SEM) analysis of material used for actual semiconductor piping confirmed that corrosion begins at the delta-ferrite and austenite boundaries. These results confirm the need to control delta-ferrite content in AISI 316L stainless steel used for semiconductor piping.


2021 ◽  
Vol 42 ◽  
pp. 57-62
Author(s):  
Maria Stoicănescu

The 1.4301 stainless steel is part of the category of austenitic stainless steels, steels which do no undergo heat treatments in general, as they are intended for hot plastic deformation in particular. The aim of the research presented in this paper was to obtain significantly improved characteristics of the resistance properties in relation to the values obtained under classical conditions, by applying heat treatments. Samples taken from the delivery state material underwent annealing, quenching and ageing heat treatments. Subsequently, the samples thus treated were subjected to tests enabling the determination of the correlations between the heat treatment parameters, the structure and the properties.


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