scholarly journals Changes of the Magnetic Properties during Heat Treatment in AISI 304

2018 ◽  
Vol 47 (4) ◽  
pp. 290-294 ◽  
Author(s):  
Tatiana Oršulová ◽  
Peter Palček ◽  
Jozef Kúdelčík
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Structural Changes ◽  
Austenitic Stainless Steels ◽  
Hardness Test ◽  
Optical Microscope ◽  
Cold Forming ◽  
Aisi 304 ◽  
Light Optical Microscope ◽  
Steel Aisi

The aim of this study was to evaluate changes of the magnetic properties during heat treatment in austenitic stainless steel AISI 304. Investigated changes were caused by plastic deformation in material. Specific composition of alloying elements in austenitic stainless steels has got influence on their deformation behavior. Samples were heat treated before measurement of magnetic properties in different intervals of temperatures. The first series of measurements has shown, that it is necessary to make more precise analysis of temperature intervals in the second part of experiment. For verification of structural changes in material there was used hardness test Vickers method and observation by light optical microscope. There was proven that AISI 304 is slightly magnetic after cold forming, although in general it is considered as non-magnetic.

Structural changes and physical properties of Fe–Ni-based metallic glasses rapidly heated by pulsed electrical currents

1991 ◽  
Vol 6 (5) ◽  
pp. 1028-1034 ◽  
Author(s):  
L. Zaluski ◽  
A. Zaluska ◽  
M. Kopcewicz ◽  
R. Schulz
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Metallic Glasses ◽  
Structural Changes ◽  
Annealing Treatment ◽  
Electrical Current ◽  
Liquid Nitrogen Temperature ◽  
Alpha Phase ◽  
Thermal Spike ◽  
Electrical Currents

Fe–Ni–Si–B metallic glasses have been annealed and crystallized using short electrical current pulses. Two types of electrical heat treatment have been used. The first one is an isothermal annealing treatment using a very high initial heating rate while the second one is a thermal spike applied on an amorphous sample held at various initial temperatures. The microstructure of the alloys after heat treatment has been characterized by x-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy. The thermal and magnetic properties of the samples measured by DSC and hysteresis loop tracer have been studied after the various heat treatments and correlated with the microstructure of the alloys. The crystallization at high temperatures produces the gamma phase only, while at low temperatures, a mixture of the gamma and alpha phases (the alpha phase being predominant) is usually observed. The samples initially held at liquid nitrogen temperature and heat treated with a thermal spike remain amorphous and show improved magnetic properties (lower coercive field and higher induction at saturation) without loss of ductility.

Effect of Ageing Treatment on the Microstructures of Ti-50.7at.%Ni Shape Memory Alloy

2013 ◽  
Vol 686 ◽  
pp. 180-191
Author(s):  
Kurnia Hastuti ◽  
Esah Hamzah ◽  
Jasmi Hashim
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Ageing Time ◽  
Solution Treatment ◽  
Hardness Test ◽  
Optical Microscope ◽  
Atomic Diffusion ◽  
Ageing Treatment ◽  
The Matrix ◽  
One Step

In this study, a commercial Ti-50.7at.%Ni was subjected to solution treatment at 800oC and 900oC for one hour followed by ageing at 300oC, 400oC, 500oC and 600oC for 1 hour, 2 hours and 4 hours respectively. Characterization of the material using optical microscope, XRD, FESEM and EDX has shown that the presence of Ti2Ni and Ti-rich precipitates in the as-received material remained unchanged even after heat treatment. The presence of oxygen in the air condition heat treatment has stabilized Ti2Ni since this condition causing the formation of Ti4Ni2O which is also determined as Ti2Ni due to their same crystal structure. The formation of Ti3Ni4 precipitates during ageing encouraged the establishment of R phase instead of martensite due to the depletion of Ni content in the matrix. Ageing treatment at 300oC generates two steps of R phase transformation due to the differences in Ni composition in the matrix at the grain boundary and grain interior region. However, for samples subjected to ageing at higher temperature, 400-500oC, only one step of R phase transformation occurred because Ni atomic diffusion was not forbidden in the high temperature. Hardness test performed on the samples revealed that increasing the ageing time will increase the hardness of material; however for the sample aged at 600oC, increasing the ageing time would reduce the hardness due to dissolution of Ti3Ni4 precipitaes into the matrix.

CHARACTERIZATION OF THE SINTERED Nd15Fe77B8 ALLOY

2011 ◽  
Vol 25 (06) ◽  
pp. 877-884
Author(s):  
L. HADJADJ
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Optical Microscope ◽  
The Other ◽  
Average Value ◽  
Nd15fe77b8 Alloy

In this work the purpose is, in addition to the determination of microhardness, to get some information about the effect of heat treatment on the microstructure of the magnetic Nd 15 Fe 77 B 8 alloy. For this study we have used an optical microscope and an electronic microprobe. The results show that the structure of the Nd 2 Fe 14 B phase, which confers good mechanical and magnetic properties on the alloy, is well tetragonal, as mentioned in several works. The morphology, the concentration and the quantity of this phase depend on the temperature of annealing. The microhardness of the phase has an average value between those of the other involved phases.

Grain Boundary Engineering of Metals by Thermo-Mechanical Treatment

2010 ◽  
Vol 659 ◽  
pp. 349-354
Author(s):  
Péter János Szabó
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stainless Steels ◽  
Mechanical Treatment ◽  
Austenitic Stainless Steels ◽  
Grain Boundary Engineering ◽  
Aisi 304 ◽  
Relative Fraction ◽  
Heat Treated ◽  
Thermo Mechanical Treatment

The relative fraction of the special grain boundaries can be increased by thermo-mechanical treatments. During this work, AISI 304-type austenitic stainless steels were plastically deformed and heat treated under different conditions, and then the grain boundary network, which developed during the treatments was investigated. Results showed that cyclic application of large cold rolling (30% reduction of thickness) and quick heat treatment at high temperature (800 °C, 2 minutes) gave the best grain boundary network. A possible reason of this behaviour is that grains which did not recrystallize after the first cycle, stored a high elastic energy, which helped the grain boundary motions in the next cycles. To characterize the developed grain boundary network, different parameters are also suggested in this paper.

scholarly journals Electron Beam Brazing of Austenitic Stainless Steel AISI 304

2021 ◽  
Author(s):  
Krzysztof Kwieciński ◽  
Piotr Śliwiński
Keyword(s):  
Stainless Steel ◽  
Electron Beam ◽  
Structural Changes ◽  
High Efficiency ◽  
Aisi 304 ◽  
Brazed Joints ◽  
Steel Aisi ◽  
Wetting Process ◽  
Filler Metals ◽  
Stainless Steel Aisi

Electron beam brazing is a joining technology combining the advantages of a precisely controlled heat source and those of vacuum brazing process. The oxide layer decomposes in high-temperature vacuum conditions, which improves the wetting process and, consequently, leads to the obtainment of more favourable properties of the brazed joint. In comparison with brazing in vacuum furnaces, the electron beam brazing process enables the precise heating of selected areas without the necessity of heating the entire element, which, in turn, results in smaller structural changes in the brazed material and the lower consumption of energy. During tests discussed in this article, sheets made of stainless steel AISI 304 were brazed using various copper and silver filler metals. Brazed joints were subjected to microstructural tests and shear strength tests. The results revealed the high efficiency of the electron beam brazing of corrosion-resistant steel sheets using filler metals.

scholarly journals ANALISIS PENGARUH PARAMETER PENGELASAN GTAW PADA STAINLESS STEEL AISI 304 TERHADAP SIFAT MEKANIS DAN STRUKTUR MIKRO

POROS ◽  
2018 ◽  
Vol 15 (1) ◽  
pp. 53
Author(s):  
Tumpal Ojahan Rudy ◽  
Yusup Hendronursito ◽  
Daniel Anggi S
Keyword(s):  
Stainless Steel ◽  
Gas Flow ◽  
Hardness Test ◽  
Taguchi Methods ◽  
Rockwell Hardness ◽  
Aisi 304 ◽  
Steel Increase ◽  
Steel Aisi ◽  
Best Parameter

Abstract: Stainless steel common worn in industry because it has the mechanical properties of a strong, the physical properties of a good, can be recycled without reducing the quality of its constituent compound, decorative and easily cleared, resistant to corrosion, capable of preventing contamination so that the use of stainless steel increase significantly. The use of stainless steel can not be separated from the process of welding, hence writer do research by varying discharge a stream of gas (13,17,21 liter per minute), current (70,130,180 ampere) And types of electrodes (EWLa-1.5, EWTh-2, EWCe-2) With the design Taguchi L9. The purpose of research to know the influence of parameter against the force pull, violence and structure micro, using of GTAW welding with Taguchi methods. The results of tensile test: yield stress dust the highest to parameter stream of gas 17 liters per minutes, the current 70 ampere, electrodes EWLa-1.5 gold with the 387 MPa, maximum stress to the flow of gas 21 liters per minutes, the current 70 ampere, electrodes EWLa-1.5 gold with the 648 MPa and strain to the low of gas 17 liters per minutes, the current 70 ampere, electrodes EWTh-2 red with the 62,2 %. The Rockwell hardness regional of weld to gas flow is 17 liters per minutes, the current 130 ampere, electrodes EWCe-2 grey the hardness poin is 74,2 HRb. Regional HAZ to the gas flow is17 liters per minutes, the current 180 ampere, electrodes EWLa-1.5 gold of 77,3 HRb. Best parameter with the taguchi method to tensile streng of gas flow 21 liter per minutes, the current 70 ampere and types of electrodes EWLa-1.5. Against rockwell hardness test (HRb) found in a stream of gas 17 liter per minutes, the current 130 ampere and types of electrodes EWCe-2.The phase that is formed before welding at micro structure is the phase austenite and the crom, nickel through welding there are adding the phase carbide crom, only the size of the widening weld and haz different. 

Quantitative Analysis of the Sensitization of an Austenitic Stainless Steel Aged between 600 and 900°C through Electrochemical and Microstructural Measurements

2020 ◽  
Vol 1012 ◽  
pp. 430-435
Author(s):  
Ramaiany Carneiro Mesquita ◽  
Ariele Rebeca Martins Ribeiro ◽  
Cintia Leite Gonçalves ◽  
Diogo Marcelo Lima Ribeiro ◽  
Sarah Caroline Gomes Caldas
Keyword(s):  
Stainless Steel ◽  
Quantitative Analysis ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Microstructural Analysis ◽  
Austenitic Stainless Steels ◽  
Aisi 304 ◽  
Temperature Range ◽  
Steel Aisi ◽  
Stainless Steel Aisi

Is the concern with latent phenomenon of sensitization, as it exposes austenitic stainless steels to one of the most severe types of corrosion, intergranular, caused by chrome impoverishment in some regions after the material has been treated thermally in a temperature range between 450°C and 850°C. The aim of this study is to identify the conditions under which the stainless steel AISI 304 austenitic will sensitize, microstructural analysis and reactivation potentiodynamics technique by Double cycle method (DL-EPR). In steel samples were subjected to different ranges of time and temperature. The behavior of the degree of sentiment reveals that the rainfall happens so intense under the conditions under study with the exception of 900oC - 1, 2, and 6, which was observed and proven both by microstructural analysis and the DL-EPR.

Effect of Heat Treatment on Deformation Induced Martensite in Austenitic Stainless Steel

2012 ◽  
Vol 510-511 ◽  
pp. 214-220
Author(s):  
Aamer Nusair Khan ◽  
S.K. Mehmood ◽  
K. Mehmood
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Texture Component ◽  
Structural Control ◽  
Aisi 304 ◽  
Heat Treated ◽  
Steel Aisi

Austenitic stainless steel with submicron gain size has been attracted due to fine structural control of mechanical properties. In order to achieve a submicron grain size, meta-stable austenitic steel AISI 304 is severely cold deformed and then annealed to different heat treatment cycles. The heat treated samples were then tested for metallurgical phase change, texture components and hardness. It was observed that at 750°C, all the martensite transformed completely into austenite. Further, at the same temperature, it was observed that the texture component {221}<232> was the dominant texture component.

Quenching Heat Treatment Effects on the Mechanical and Microstructure Properties of AISI 304 Type Welded by GMAW Process Using Different Shielding Gases

2013 ◽  
Vol 465-466 ◽  
pp. 983-987
Author(s):  
Rasdi Deraman ◽  
M.N. Berhan
Keyword(s):  
Heat Treatment ◽  
Arc Welding ◽  
Treatment Process ◽  
Gas Metal Arc Welding ◽  
Shielding Gas ◽  
Aisi 304 ◽  
Metal Arc Welding ◽  
Operation Process ◽  
Steel Aisi ◽  
Stainless Steel Aisi

As-received samples of an austenitic stainless steel AISI 304 type was welded by Gas metal arc welding (GMAW) robotic operation process using ER308L-Si filler metal wire. Two different atmospheres were used: 68% Argon plus 32% CO2, and 100% Argon. The aim of this study is investigates the influence of quenching heat treatment on the mechanical and microstructure properties of AISI 304 type which welded by GMAW under different shielding gas compositions. The fractured surfaces of the tensile test specimens examined using scanning electron microscopy (S.E.M). The results showed that the welding using shielding gas of 68% Argon plus 32% CO2stronger than 100% Argon. After performed quenching heat treatment process, both specimens experienced a slight decreased in hardness.

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