scholarly journals A Comparative Study of Hydrogen-Induced Cracking Resistances of API 5L B and X52MS Carbon Steels

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Rodrigo Monzon Figueredo ◽  
Mariana Cristina de Oliveira ◽  
Leandro Jesus de Paula ◽  
Heloisa Andréa Acciari ◽  
Eduardo Norberto Codaro
Keyword(s):  
Hydrogen Permeation ◽  
Carbon Steels ◽  
Corrosion Products ◽  
Metallographic Analysis ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Standard Testing ◽  
Hydrogen Induced Cracking ◽  
Before And After

Susceptibility to hydrogen-induced cracking of API 5L B and X52MS low-carbon steels in NACE 177-A, 177-B, and 284-B solutions has been investigated by the present work. A metallographic analysis of these steels was performed before and after NACE TM0284 standard testing. Corrosion products were characterized by scanning electron microscopy and X-ray dispersive energy spectrometry, which were subsequently identified by X-ray diffraction. Thus it was found that pH directly affects the solubility of corrosion products and hydrogen permeation. Both steels showed generalized corrosion in solution 177-A, and a discontinuous film was formed on their surfaces in solution 177-B; however, only the API 5L B steel failed the HIC test and exhibited greater crack length ratio in solution 177-A. In solution 284-B whose pH is higher, the steels exhibited thick mackinawite films with no internal cracking.

scholarly journals Texture Evolution during Annealing of Warm Rolled Cr-Containing Low Carbon Steels

2007 ◽  
Vol 558-559 ◽  
pp. 295-300 ◽  
Author(s):  
Elena V. Pereloma ◽  
Azdiar A. Gazder ◽  
John J. Jonas ◽  
Chris H.J. Davies
Keyword(s):  
Texture Evolution ◽  
Shear Bands ◽  
Carbon Steels ◽  
Lower Amount ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Low Carbon Steels ◽  
X Ray ◽  
Cr Content ◽  
Back Scattering

Two low carbon steels alloyed with 0.48wt% and 0.78wt% Cr were warm rolled to 65% reduction at 640°C. Annealing was carried out at 710°C to achieve a range of recrystallized volume fractions up to 100%. Texture analysis was performed by X-ray diffraction and Electron Back Scattering Diffraction. During the initial stages of recrystallization, more recrystallized grains nucleated at shear bands than at grain boundaries in the 0.48wt%Cr steel, whereas this was not the case in the 0.78wt%Cr steel. This is associated with a decrease in the propensity to form shear bands due to the lower amount of C in solid solution in the high-Cr steel. Additionally, the nuclei showed a preference to develop the same fiber as the deformed region within which they nucleated. In both steels, an increase in the annealing time led to the deterioration of the ND (or γ) –fiber and a strengthening of both the RD (or α) –fiber and Goss component. In the fully recrystallized samples, the ND component was somewhat stronger in the steel with the higher Cr content.

Microstructure and Mechanical Properties of AISI 8620 Steel Processed by ECAP

2014 ◽  
Vol 1611 ◽  
pp. 89-94
Author(s):  
Diana M. Marulanda ◽  
Jair G. Cortés ◽  
Marco A. Pérez ◽  
Gabriel García
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Equivalent Strain ◽  
Sem Analysis ◽  
Structure Evolution ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angular Pressing ◽  
Before And After

ABSTRACTThe aim of this work is to process by equal channel angular pressing (ECAP) a low carbon – triple-alloyed steel containing 0.2% C, 0.5% Cr, 0.6% Ni, 0.2% Mo and 0.8 Mo. The process is performed at room temperature for up to four passes using route Bc with an equivalent strain of ∼0.6 after a single pass. Structure evolution before and after deformation is studied using scanning electron microscopy (SEM) and x-ray diffraction (XRD) and mechanical properties are assessed by microhardness and tensile testing. A significant improvement of the mechanical properties is found with increasing number of ECAP passes. Micro-hardness increases from 216 HV for the initial sample to 302 HV after four passes and tensile strength increases to 1200 MPa compared with 430 MPa prior to ECAP. X-ray diffraction and SEM analysis show changes in the original ferritic-perlitic structure through ferrite grain refinement and the deformation of perlite. This nickel-chromium-molybdenum alloy is used in manufacturing as gear material, and when it is hardened and formed through carburizing or boronizing it can be used to make hard-wearing machine parts. However, the ECAP process has not been used to harden this steel and to change its structure to obtain better mechanical performance.

Formation of the {111} and {111} Recrystallization Texture in Deep Drawing Low Carbon Steel

2012 ◽  
Vol 535-537 ◽  
pp. 687-691 ◽  
Author(s):  
Xiao Li ◽  
Ping Yang ◽  
Li Meng
Keyword(s):  
Recrystallization Texture ◽  
Electron Backscatter Diffraction ◽  
Early Stage ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cold Rolled ◽  
Backscatter Diffraction

The formation of 111-112 and 111-110 recrystallization textures during annealing of cold rolled low carbon steels at low heating rate was investigated by electron backscatter diffraction (EBSD) and X-ray diffraction techniques. The orientation characteristics during recrystallization of this steel were determined, results show that there is a strong competition between the 111-112 component and the 111-110 component along the γ-fiber. The former was developed from the deformed matrix with the same orientation by means of subgrain coalescence at early stage of recrystallization, while the latter nucleated at the grain boundary areas of deformed grains with 111-112 or 112-110 orientations by means of preferred nucleation and evolved into stable recrystallization texture at later stage of recrystallization.

Determination of equilibrium transformation temperatures Ae3 and Ae1 for low-carbon steels using the in situ high-temperature X-ray diffraction technique

2010 ◽  
Vol 25 (1) ◽  
pp. 31-37
Author(s):  
F. Equihua ◽  
A. Salinas
Keyword(s):  
High Temperature ◽  
Carbon Steels ◽  
Simulation Software ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Transformation Temperatures ◽  
X Ray ◽  
Diffraction Patterns ◽  
Integrated Intensities

This paper describes a method to determine the equilibrium transformation temperatures in low C steels using the in situ high-temperature X-ray diffraction technique. The samples were heated and then cooled from 1000 to 720 °C in a stepwise manner decreasing to −10 °C. Austenite and ferrite fractions were determined by a quantitative method using the integrated intensities of austenite (111)γ and ferrite (110)α peaks from X-ray diffraction patterns. The effect of the temperature on interplanar d spacings of (111) and (110) crystallographic planes was determined using 2θ maximum positions of the austenite (111)γ and ferrite (110)α peaks. The equilibrium transformation temperatures were determined to be Ae1=720 °C and Ae3=950 °C. The results are in excellent agreement with those obtained by dilatometric analysis and Thermo-Calc phase diagram simulation software. In addition, the results were supported by microstructural observations: the formation of thin ferrite films (5–10 μm) was observed at temperatures near to experimental Ae3.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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