scholarly journals Resistance of Aluminide Coatings on Austenitic Stainless Steel in a Nitriding Atmosphere

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 162
Author(s):  
Karolina Wierzbowska ◽  
Agnieszka Elżbieta Kochmańska ◽  
Paweł Kochmański
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Oxidation Process ◽  
Protective Coatings ◽  
Reference Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Nitriding ◽  
Aluminide Coatings ◽  
Gas Corrosion

A new slurry cementation method was used to produce silicide-aluminide protective coatings on austenitic stainless steel 1.4541. The slurry cementation processes were carried out at temperatures of 800 and 1000 °C for 2 h with and without an additional oxidation process at a temperature of 1000 °C for 5 min. The microstructure and thickness of the coatings were studied by scanning electron microscopy (SEM). The intention was to produce coatings that would increase the heat resistance of the steel in a nitriding atmosphere. For this reason, the produced coatings were subjected to gas nitriding at a temperature of 550–570 °C in an atmosphere containing from 40 to 60% of ammonia. The nitriding was carried out using four time steps: 16, 51, 124, and 200 h, and microstructural observations using SEM were performed after each step. Analysis of the chemical composition of the aluminide coatings and reference sample was performed using wavelength (WDS) and energy (EDS) dispersive X-ray microanalysis, and phase analysis was carried out using X-ray diffraction (XRD). The resistance of the aluminide coatings in the nitriding atmosphere was found to depend strongly on the phase composition of the coating. The greatest increase in resistance to gas corrosion under nitriding atmosphere conditions was achieved using a manufacturing temperature of 1000 °C.

scholarly journals Residual Stress Tensor Distributions in Cracked Austenitic Stainless Steel Measured by Two-Dimensional X-Ray Diffraction Method

2014 ◽  
Vol 996 ◽  
pp. 128-134 ◽  
Author(s):  
Youichi Saito ◽  
Shunichiro Tanaka
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Tensor ◽  
Equivalent Stress ◽  
Diffraction Method ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Stress Concentrations ◽  
X Ray

The residual stress tensor for cracked austenitic stainless steel was measured by a two-dimensional X-ray diffraction method. Higher von Mises equivalent stress concentrations, attributed to hot crack initiation, were obtained at both crack ends. The stress of 400 MPa at the crack end in the columnar grain region was about two-fold larger than that of 180 MPa in the equiaxed grain region. This difference was caused by a depression in the cast slab.

Measuring residual stresses in stainless steel—recent experiences within a VAMAS exercise

2009 ◽  
Vol 24 (S1) ◽  
pp. S41-S44 ◽  
Author(s):  
A. T. Fry ◽  
J. D. Lord
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Residual Stresses ◽  
Best Practice ◽  
Test Procedure ◽  
Industrial Plant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Industrial Sectors

Residual stresses impact on a wide variety of industrial sectors including the automotive, power generation, industrial plant, construction, aerospace, railway and transport industries, and a range of materials manufacturers and processing companies. The X-ray diffraction (XRD) technique is one of the most popular methods for measuring residual stress (Kandil et al., 2001) used routinely in quality control and materials characterization for validating models and design. The VAMAS TWA20 Project 3 activity on the “Measurement of Residual Stresses by X-ray Diffraction” was initiated by NPL in 2005 to examine various aspects of the XRD test procedure in support of work aimed at developing an international standard in this area. The purpose of this project was to examine and reduce some of the sources of scatter and uncertainty in the measurement of residual stress by X-ray diffraction on metallic materials, through an international intercomparison and validation exercise. One of the major issues the intercomparison highlighted was the problem associated with measuring residual stresses in austenitic stainless steel. The following paper describes this intercomparison, reviews the results of the exercise and details additional work looking at developing best practice for measuring residual stresses in austenitic stainless steel, for which X-ray measurements are somewhat unreliable and problematic.

scholarly journals X-ray diffraction characterization of ion-implanted austenitic stainless steel

2005 ◽  
Vol 195 (1) ◽  
pp. 8-16 ◽  
Author(s):  
M.J. Marques ◽  
J. Pina ◽  
A.M. Dias ◽  
J.L. Lebrun ◽  
J. Feugeas
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Implanted

Effect of Hydrogen on the Micro- and Macro-Strain near the Surface of Austenitic Stainless Steel

2014 ◽  
Vol 936 ◽  
pp. 1298-1302 ◽  
Author(s):  
Osamu Takakuwa ◽  
Yuta Mano ◽  
Hitoshi Soyama
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Compressive Stress ◽  
Parameter Method ◽  
Fundamental Parameter ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Hydrogen Charging

The objective of this study is to evaluate the effect of hydrogen on the micro-and macro-strain of austenitic stainless steel using X-ray diffraction. When hydrogen is trapped in lattice sites, it can affect both the micro-and macro-strain. The micro-strain was evaluated through fitting profiles to measured X-ray diffraction profile using a fundamental parameter method. The macro-strain, i.e., the residual stress, was evaluated by a 2D method using a two-dimensional PSPC. The experimental samples were charged with hydrogen by a cathodic charging method. The results revealed that the induced residual stress was equi-biaxial and compressive, and that the micro-strain increased. Both of these varied rapidly with increasing hydrogen charging time. Saturation occurred at a compressive stress of around 130 MPa. On reaching saturation, the hydrogen charging was terminated and desorption of hydrogen began at room temperature. Then, the strains decreased and the compressive stress reverted, ultimately, to a tensile stress of 180 MPa. Martensitic transformation occurred due to hydrogen charging and this had a significant effect on the X-ray diffraction profile.

Residual Stress by X-Ray Diffraction and Microstructure for Multi-Pass Girth Welded Pipe Joint in Austenitic Stainless Steel Type 316L

2011 ◽  
Author(s):  
Tadafumi Hashimoto ◽  
Shigetaka Okano ◽  
Shinro Hirano ◽  
Masahito Mochizuki ◽  
Kazutoshi Nishimoto
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Diffraction Method ◽  
Incident Beam ◽  
Austenitic Stainless Steels ◽  
Secondary Phase ◽  
Primary Phase ◽  
X Ray Diffraction ◽  
X Ray

Residual stress due to welding can result in brittle fracture, fatigue failure, and stress corrosion cracking in welded structures. Measuring residual stresses are of great importance, if crack propagation needs to be evaluated. However, it is especially known that the X-ray diffraction method makes remarkable different for austenitic stainless steel, because the microstructures in welds change from the original microstructures during welding thermal cycle. That is, there are the preferred orientation due to the unidirectional solidification and the grain growth in the heat-affected zone. In order to average the sin2Ψ plots to exclude them, Ψ oscillation of ±3 deg was performed and the incident beam size was broadened to 4 by 4 mm. Consequently, typical residual stress distributions due to welding were obtained to various conditions. The residual stress distribution measured by X-ray diffraction agrees very well with that the estimated by thermal-elastic-plastic analysis, if the spatial resolution is correlated. It is attributed that the δ-ferrite grows as the primary phase and the austenite precipitates or crystallizes as the secondary phase. When the secondary austenite nucleates with the Kurdjiumov-Sachs relationship which satisfy δ{110}//γ{111} and δ<111>//γ<110>, plate-like austenite grows randomly into the ferrite and austenite grains are braked up. That is, Specific systems in austenitic stainless steels should be classified, as a material that residual stress can be measured accurately by X-ray diffraction.

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