On the Influence of Crystallographic Texture on HIC

2006 ◽  
Author(s):  
F. Caleyo ◽  
V. Venegas ◽  
J. M. Hallen ◽  
J. E. Araujo ◽  
T. Baudin
Keyword(s):  
Crystallographic Texture ◽  
Coincidence Site Lattice ◽  
Orientation Imaging Microscopy ◽  
Controlled Rolling ◽  
Grain Boundary Engineering ◽  
Low Carbon ◽  
Texture Measurement ◽  
Pipeline Steels ◽  
Orientation Imaging ◽  
Low Sulfur

This work presents the results of ongoing investigations aimed at determining the influence of crystallographic texture, microtexture and mesotexture on hydrogen induced cracking (HIC) in low carbon pipeline steels. HIC samples of two steels were investigated using X-ray diffraction texture measurement and Orientation Imaging Microscopy (OIM™). The first steel is a low strength API 5L X46 retired from service and the second is a low sulfur ASTM A106 steel. The results of this work confirm the feasibility of improving the HIC resistance of pipeline steels through crystallographic texture control and grain boundary engineering. Controlled rolling schedules can be proposed in order to induce a crystallographic texture dominated by the {112}//ND, {111}//ND and {011}//ND fibres. Such a texture is expected to decrease significantly the steel susceptibility to HIC by: (i) reducing the number of available transgranular and intergranular low resistance cleavage paths provided by the {001}//ND oriented grains, (ii) reducing the probability of crack coalescence and stepwise HIC propagation and (iii) increasing the number of high resistance intergranular crack paths provided by coincidence site lattice (CSL) and low angle boundaries with the lowest possible energy.

Ultra Grain Refinement of Low C Steels by Accumulative Roll Bonding

2006 ◽  
Vol 503-504 ◽  
pp. 311-316 ◽  
Author(s):  
I. Salvatori
Keyword(s):  
Accumulative Roll Bonding ◽  
Orientation Imaging Microscopy ◽  
Low Carbon Steel ◽  
Small Samples ◽  
Low Carbon ◽  
High Angle ◽  
Misorientation Distribution ◽  
Roll Bonding ◽  
Orientation Imaging ◽  
Annealing Conditions

Refinement of grain size is one of the biggest challenges to produce steels with improved combination of strength and toughness. Ultrafine structures are being produced world-wide on various materials, including low carbon steel, using different types of processes. However, the majority of these processes also exhibit severe limitations because they are generally restricted to small samples and are difficult to be implemented on an industrial scale. A promising technique for industrial implementation is the Accumulative Roll Bonding (ARB), a process able to supply large samples, even in the laboratory scale. In this paper, warm intense straining (ε = 4) by ARB was applied to a plain low-C steel in order to develop ultrafine grains, aiming at sizes around 1-2 μm, suitable to maintain an adequate combination of strength and ductility. The effect of annealing conditions on the evolution of the work-hardened microstructure and the bonding behaviour after each pass were investigated. Orientation Imaging Microscopy was used to investigate the microstructure and give a quantitative assessment of high angle and low angle boundaries. It is showed that the frequency of high angle grain boundaries increases with the strain but the misorientation distribution remained far from that typical of a recrystallised material.

Hydrogen-Induced Crack Interaction and Coalescence: The Role of Local Crystallographic Texture

2010 ◽  
Author(s):  
V. Venegas ◽  
F. Caleyo ◽  
J. M. Hallen ◽  
T. Baudin
Keyword(s):  
Fracture Mechanics ◽  
Crystallographic Texture ◽  
Mixed Mode ◽  
Orientation Imaging Microscopy ◽  
Mixed Mode Fracture ◽  
Crack Interaction ◽  
Elastic Materials ◽  
Pipeline Steels ◽  
Linear Elastic

The role of local crystallographic texture (microtexture) in hydrogen-induced crack interaction and coalescence is investigated in pipeline steels using stress simulation and orientation imaging microscopy. It is shown that, depending on the material’s microtexture, crack interaction and coalescence can significantly depart from the conditions predicted by the mixed-mode fracture mechanics of isotropic linear elastic materials. The results of stress simulations and microtexture analyses conducted on several observed crack interaction zones show that the presence of cleavage planes and slip systems favorably oriented to the mixed-mode stresses can activate low-resistance transgranular paths along which cracks can merge. In such situations, the response of the material to the mixed-mode stress state resulting from crack interaction produces results drastically different to that predicted by the fracture mechanics of isotropic linear elastic materials. This evidences the need for considering the material’s crystallographic texture when developing predictive models for the stepwise propagation of hydrogen-induced cracking in pipeline steels.

Static Recrystallization Kinetics and Crystallographic Texture of Nb-Stabilized Ferritic Stainless Steel Based on Orientation Imaging Microscopy

2017 ◽  
Vol 48 (3) ◽  
pp. 1288-1309 ◽  
Author(s):  
Paula Oliveira Malta ◽  
Davi Silva Alves ◽  
Aline Oliveira Vasconcelos Ferreira ◽  
Iane Dutra Moutinho ◽  
Carolina Arriel Pedroso Dias ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Crystallographic Texture ◽  
Static Recrystallization ◽  
Orientation Imaging Microscopy ◽  
Recrystallization Kinetics ◽  
Orientation Imaging

BETHSTAR 60

Alloy Digest ◽  
1986 ◽  
Vol 35 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Steel Plate ◽  
High Stress ◽  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Bethlehem Steel Corporation ◽  
Low Sulfur ◽  
Minimum Yield

Abstract BethStar 60 steel plate is a high-strength product with a 60,000 psi minimum yield strength. It contains low carbon and low sulfur and has outstanding toughness, weldability and formability. It provides the design engineer with a an economical high-strength low-alloy (HSLA) grade that can be fabricated readily. Applications include weight-sensitive components subject to high stress such as frames for large off-highway haulers. This datasheet provides information on composition, physical properties, microstructure, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-421. Producer or source: Bethlehem Steel Corporation.

Influence of Dynamic Recrystallisation on Texture Formation in ECAP deformed Nickel

2007 ◽  
Vol 558-559 ◽  
pp. 575-580 ◽  
Author(s):  
Werner Skrotzki ◽  
Burghardt Klöden ◽  
I. Hünsche ◽  
Robert Chulist ◽  
Satyam Suwas ◽  
...  
Keyword(s):  
Orientation Imaging Microscopy ◽  
High Energy ◽  
Texture Gradient ◽  
Texture Formation ◽  
Microstructure Formation ◽  
Fcc Metals ◽  
Orientation Imaging ◽  
Angular Pressing ◽  
Dynamic Recrystallisation ◽  
Number Of Passes

3N nickel has been deformed by equal channel angular pressing (ECAP) at 400°C up to 3 passes using route A. The texture with respect to position in the deformed billet, i.e. from top to bottom, has been measured with high-energy synchrotron radiation. It is characterized by texture components typical for simple shear in the intersection plane of the square-shaped 90° bent channel. Besides, an oblique cube component is observed. Orientation imaging microscopy clearly shows that this component is due to partial recrystallization. Intensities of the texture components as well as deviations from their ideal shear positions vary from the top to the bottom of the billet and with the number of passes. The change of the intensity of texture components and the texture gradient investigated is discussed. Special emphasis is put on the influence of dynamic recrystallization on texture and microstructure formation during ECAP of fcc metals.

Structure Development during ECAP and Subsequent Creep of Aluminium

2007 ◽  
Vol 539-543 ◽  
pp. 493-498 ◽  
Author(s):  
Ivan Saxl ◽  
Vàclav Sklenička ◽  
L. Ilucová ◽  
Milan Svoboda ◽  
Petr Král
Keyword(s):  
High Purity ◽  
Grain Orientation ◽  
Orientation Imaging Microscopy ◽  
Structural Inhomogeneity ◽  
Structure Development ◽  
Creep Fracture ◽  
Orientation Imaging ◽  
Purity Aluminium ◽  
High Purity Aluminium ◽  
Creep Loading

Considerable structural inhomogeneity and anisotropy were found even after eight ECAP passes in high purity aluminium and the creep loading of ECAP material at 473K, 15MPa resulted in scattered fracture times ~ 20-60 hours. The structure revealed by orientation imaging microscopy with different disclination bounds was analysed by stereological methods. The effect of inhomogeneity and grain orientation on the creep fracture time was assessed.

Strengthening Low Carbon Steels for Oil and Gas Spiral Welded Pipes

2006 ◽  
Author(s):  
I. Yu. Pyshmintsev ◽  
D. A. Pumpyanskyi ◽  
Yu. O. Kamenskih ◽  
I. N. Poznyakovsky ◽  
I. L. Permyakov
Keyword(s):  
Oil And Gas ◽  
Controlled Rolling ◽  
Carbon Steels ◽  
Low Carbon ◽  
Line Pipe ◽  
Low Carbon Steels ◽  
Factors Affecting ◽  
Steel Processing ◽  
Line Pipe Steel ◽  
Strain Hardening Behavior

Strengthening mechanisms applied for modern line pipe steel design were studied. Low carbon steels alloyed with Mn, Mo, V, Nb processed by the way of controlled rolling were developed for spiral welded X65-X80 line pipes up to 1420 mm diameter. Formation of the microstructure during steel processing was studied. The effects of typical microstructure for the steels on mechanical properties, strain hardening behavior and Bauschinger effect were studied. Main metallurgical factors affecting on strength measured in plates and pipes were revealed using physical and computer simulations.

scholarly journals Defect and Damage Evolution Quantification in Dynamically-Deformed Metals Using Orientation-Imaging Microscopy

2010 ◽  
Vol 654-656 ◽  
pp. 2297-2302 ◽  
Author(s):  
George T. Gray III ◽  
Veronica Livescu ◽  
Ellen K. Cerreta
Keyword(s):  
Detonation Wave ◽  
Damage Evolution ◽  
Shock Loading ◽  
Volume Fraction ◽  
Orientation Imaging Microscopy ◽  
Electron Back Scatter Diffraction ◽  
Orientation Imaging ◽  
Deformation Twins

Orientation-imaging microscopy offers unique capabilities to quantify the defects and damage evolution occurring in metals following dynamic and shock loading. Examples of the quantification of the types of deformation twins activated, volume fraction of twinning, and damage evolution as a function of shock loading in Ta are presented. Electron back-scatter diffraction (EBSD) examination of the damage evolution in sweeping-detonation-wave shock loading to study spallation in Cu is also presented.

Sign in / Sign up

Export Citation Format

Share Document