scholarly journals Effect of Heat Treatment on the Phase Composition and Corrosion Resistance of 321 SS Welded Joints Produced by a Defocused Laser Beam

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3720 ◽  
Author(s):  
Sergey Vyacheslavovich Kuryntsev
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Laser Beam ◽  
Welded Joints ◽  
Intergranular Corrosion ◽  
Alloying Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Δ Ferrite

The effect of heat treatment of welded joints made of steel 321 on corrosion resistance, phase composition, residual stresses, and distribution of alloying elements was studied using optical microscope (OM) and scanning electron microscope (SEM), electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and intergranular corrosion testing (IGC). Samples previously obtained by the authors using defocused laser beam, which led to the formation of directionally crystallized austenite with lathy and skeletal δ-ferrite, were investigated. Based on X-ray diffraction studies in the base metal, the maximum number of peaks of various phases was presented, which decreased after exposure to the heating effect of the welding process and subsequent heat treatment. The distribution of alloying elements, in particular, Ti and Si, was significantly affected by heat treatment depending on the regimes. A spot chemical analysis showed that the nickel content differs in δ-ferrite and austenite by 1.5%–2% whereas the chromium content in these phases is not significantly different. Tests have shown that all samples have high resistance to intergranular corrosion, which can be explained by the insufficient dissolution of titanium carbides in austenite and the absence of chromium carbides formation along austenite grain boundaries, due to high cooling rates when welding by a defocused laser beam, and as a result, the high δ-ferrite content in which chromium dissolves.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Ni-B-W-Mo COATING DEPOSITED BY ELECTROLESS METHOD

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Sodium Molybdate ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Heat Treated ◽  
Electroless Coatings

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.

Research on Properties of Amorphous Cr-C Alloy Coating in Crystallization Evolution

2012 ◽  
Vol 184-185 ◽  
pp. 1175-1180
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Bi Xue Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Adhesion Force ◽  
Alloy Coating ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Proper Values ◽  
Peak Value

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.

Effect of Heat Treatment on Microstructure and Corrosion Resistance of Ni-Cr-Mo-Fe Alloys

2012 ◽  
Vol 581-582 ◽  
pp. 773-776
Author(s):  
Er Chao Ding ◽  
Zhen Yong Man ◽  
Xin Xin Yang ◽  
Jing Tai Zhao
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Homogeneous Microstructure ◽  
X Ray ◽  
Arc Melting ◽  
Distribution Of Elements ◽  
Microstructure Morphology ◽  
Fe Alloys

The effects of heat treatment on microstructure and corrosion resistance of Ni-Cr-Mo-Fe nickel-based alloys were investigated by X-ray diffraction (XRD), metallographic microscope (MM), scanning electron microscopy (SEM) and electrochemical analysis, respectively. Experimental results indicated that the samples which were prepared via electric arc melting shielded by argon were pure solid solutions with homogeneous microstructure. Segregation of chromium element and slightly smaller grain size were found after heat treatment. Better corrosion resistance of samples was achieved after heat treatment, due to improvement of microstructure, morphology and distribution of elements.

scholarly journals Influence of Different Heat Treatment Temperatures on the Microstructure, Corrosion, and Mechanical Properties Behavior of Fe-Based Amorphous/Nanocrystalline Coatings

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 858
Author(s):  
Shenglin Liu ◽  
Yongsheng Zhu ◽  
Xinyue Lai ◽  
Xueping Zheng ◽  
Runnan Jia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Treatment Temperature ◽  
Annealing Treatment ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Different Temperatures ◽  
Sprayed Coating

Fe-based amorphous/nanocrystalline coatings with smooth, compact interior structure and low porosity were fabricated via supersonic plasma spraying (SPS). The coatings showed outstanding corrosion resistance in a 3.5% NaCl solution at room temperature. In order to analyze the effect of annealing treatment on the microstructure, corrosion resistance and microhardness, the as-sprayed coating was annealed for 1 h under different temperatures such as 350, 450, 550 and 650 °C, respectively. The results showed that the number of oxides and cracks in the coatings presented an obvious increase with increasing annealing temperature, and the corrosion resistance of the coatings showed an obvious reduction. However, the microhardness of coatings showed an important increase. The microhardness of the coating could reach 1018 HV when the heat treatment temperature reached 650 °C. The X-ray diffraction (XRD) results showed that there appeared a number of crystalline phases in the coating when the heat treatment temperature was at 650 °C. The crystalline phases led to the increase of the microhardness.

Synthesis of nanocomposite coating of electrodeposed amorphic layers of the Ni–P–W system

2020 ◽  
pp. 53-60
Author(s):  
A. V. Krasikov
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Differential Scanning Calorimetry ◽  
Phase Composition ◽  
Diffraction Analysis ◽  
Nanocomposite Coating ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The processes of the formation of the nanocomposite coating of Ni–11.5% P–5%W were studied during the heat treatment of amorphous electrodeposited layers. Using the method of differential scanning calorimetry, the temperature of the onset of crystallization of the nanocrystalline phase Ni3P was determined. X-ray diffraction analysis showed that heat treatment produces Ni3P phosphides and, presumably, Ni5P2, the size of which, according to electron microscopy, is 5–50 nm. The influence of the duration of heat treatment on the phase composition and microhardness of coatings is investigated.

scholarly journals Effect of Heat Treatment on the Microstructure and Phase Composition of ZrB2–MoSi2 Coating

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 779
Author(s):  
Marina Kovaleva ◽  
Igor Goncharov ◽  
Vseslav Novikov ◽  
Maxim Yapryntsev ◽  
Olga Vagina ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Lamellar Structure ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mosi2 Coating ◽  
Α Al2o3 ◽  
Sprayed Coating ◽  
Scanning Electron

Composite ZrB2–MoSi2 coating modified by Y2O3 and Al was prepared by a new multi-chamber detonation accelerator (MCDS) on carbon/carbon composites. Postdeposition heat treatment of the samples at 1500 °C for 1 and 6 h was carried out in air. The effect of heat treatment on the microstructure and phase composition of the ZrB2–MoSi2 coating was investigated by scanning electron microscopy and X-ray diffraction phase analysis. The as-sprayed coating presented as a dense lamellar structure, composed of m-ZrO2, t-ZrO2, some hexagonal ZrB2, and cubic Al phases. The m-ZrO2, c-ZrO2, and h-(α-Al2O3) formed at 1500 °C. The coatings after heat treatment (1 and 6 h) exhibited a structure without cracks. The porosity (~1%) of the coating did not change after heat treatment. Thin, continuous, silica-rich film covered the surfaces of ZrO2 and Al2O3 particles, and could have played a role during heat treatment by acting as a grain lubricant for particle rearrangement.

Effect of Mineralizers on MnNb2O6 Powder Prepared by Hydrothermal Method

2010 ◽  
Vol 156-157 ◽  
pp. 1010-1013
Author(s):  
Yong Ping Pu ◽  
Yong Yong Zhuang ◽  
Kai Chen ◽  
Ning Xu
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Phase Composition ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Dispersed ◽  
Scanning Electron

Pure MnNb2O6 powders was successfully prepared by hydrothermal method using Nb2O5•nH2O and Mn(NO3)2 as precursors and HCl, HF, NaOH, NH4OH solutions as mineralization agent. The phase composition and morphology of the prepared powder were characterized by X-ray diffraction and scanning electron microscopy. The effect of mineralizers on phase formation was investigated. The results show that the MnNb2O6 powders with crystallite size of ~24nm can be obtained with Mn(NO3)2 and Nb2O5•nH2O as precursors in neutral and alkaline solution at 200 for 168h. The particle size of the MnNb2O6 powder was ~300nm after heat treatment at a temperature of 600 . The SEM photographs show that the morphology of the MnNb2O6 powder are rod-like particles and the MnNb2O6 powders are highly dispersed.

scholarly journals Heat Treatment Effect in the Corrosion Resistance of the Al-Co-Mn Alloys Immersed in 3 M KOH

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
J. G. Pereyra-Hernández ◽  
I. Rosales-Cadena ◽  
R. Guardián-Tapia ◽  
J. G. González-Rodríguez ◽  
R. López-Sesenes
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Chemical Analysis ◽  
Polarization Resistance ◽  
Electrochemical Techniques ◽  
Corrosion Current ◽  
Heat Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Concentration

Al-based alloys named M1, M2, M3, M4, and M5 doped with different atomic percentage (at%) of cobalt and manganese as cast and submitted at two heat treatments (600°C and 1100°C) were analyzed by using electrochemical techniques to evaluate their corrosion resistance immersed in 3 M KOH. With the heat treatments applied to the alloys, the sample M2 (65% Al, 20% Co, and 15% Mn) observed the highest corrosion resistance with R p values of 3.0 × 10 2 , 6.2 × 10 2 , and 1.61 × 10 3   Ω · c m 2 as cast, 600°C, and 1100°C, respectively. The latter was in agreement with the I corr calculated from the polarization curves where the values decrease based on the heat treatment applied as follows: 1.60 × 10 3 > 6.16 × 10 2 > 3.07 × 10 2   mA / c m 2 for 1100, 600, and as cast, respectively. Co concentration above 20% increases the corrosion current ( I corr ) and decreases the polarization resistance of the remain samples. The chemical analysis done with EDS and X-ray diffraction made confirmed the presence of compounds such as CoAl, Co2Al5, Co2Al9, MnAl4, and MnAl6.

Microstructure and Phase Composition of (Ce, Mg)-PSZ Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1194-1196
Author(s):  
Zhi Ping Shen ◽  
Shu Cai ◽  
Zhen Dong
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Monoclinic Phase ◽  
Processing Method ◽  
Nanoporous Structure ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
X Ray ◽  
Heat Treated

Magnesia, ceria partially stabilized zirconia (Ce,Mg)-PSZ ceramics with net shape microstructure are prepared using a processing method similar to that of conventional Mg-PSZ ceramics, then heat-treated at 1500°C for different time. Microstructure and phase composition of (Ce, Mg)-PSZ samples with different amount of CeO2 doped were investigated using SEM and X-ray diffraction. The addition of CeO2 could impede the formation of monoclinic phase and inhibit the growth of cubic grains. A microstructure with net-shape cubic grains, in which tetragonal precipitates interweave to a nanoporous structure is obtained by adding 4∼8 mol% CeO2 in 10mol% MgO doped zirconia matrix and then heat treatment at 1500°C for different time. The precipitate morophology might be related with the addition of CeO2 and the heat treatment temperatures.

Effect of Heat Treatment on the Corrosion Behaviour of a Mg-Y Alloy in Chloride Medium

2010 ◽  
Vol 636-637 ◽  
pp. 491-496 ◽  
Author(s):  
M. Carboneras ◽  
Claudio J. Múnez ◽  
Pilar Rodrigo ◽  
M. Dolores Escalera ◽  
Maria Dolores López ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Corrosion Behaviour ◽  
X Ray Diffraction ◽  
Chloride Medium ◽  
X Ray ◽  
Technology Applications ◽  
Mechanical Properties And Corrosion ◽  
Surface Examination

Corrosion behaviour of a Mg-Y alloy (commercial WE54) has been studied. This alloy presents excellent retention of mechanical properties and corrosion resistance at elevated temperatures, a combination of properties that can be of interest in many technology applications. To evaluate the effect of heat treatment on the corrosion resistance, WE54 samples in extruded state and after T6 heat treatment were studied. Corrosion behaviour was evaluated by electrochemical and immersion tests in 3.5 wt.% NaCl solution at room temperature and neutral pH. Surface examination was carried out by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). It was found that corrosion resistance of the magnesium alloy WE54 in chloride medium was improved by applying the heat treatment to the material, a fact that was correlated with the developed microstructure in T6 condition.

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