scholarly journals Investigation of Hydrogen Embrittlement Susceptibility and Fracture Toughness Drop after in situ Hydrogen Cathodic Charging for an X65 Pipeline Steel

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 430 ◽  
Author(s):  
Helen Kyriakopoulou ◽  
Panagiotis Karmiris-Obratański ◽  
Athanasios Tazedakis ◽  
Nikoalos Daniolos ◽  
Efthymios Dourdounis ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
High Strength ◽  
Electrolytic Cell ◽  
Low Alloy Steels ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Alloy Steels

The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader category of High Strength Low Alloy Steels (HSLA), and its microstructure consists of equiaxed ferritic and bainitic grains with a low volume fraction of degenerated pearlite islands. The studied X65 steel specimens were extracted from pipes with 19.15 mm wall thickness. The fracture toughness parameters were determined after imposing the fatigue pre-cracked specimens on air, on a specific electrolytic cell under a slow strain rate bending loading (according to ASTM G147-98, BS7448, and ISO12135 standards). Concerning the results of this study, in the first phase the hydrogen cations’ penetration depth, the diffusion coefficient of molecular and atomic hydrogen, and the surficial density of blisters were determined. Next, the characteristic parameters related to fracture toughness (such as J, KQ, CTODel, CTODpl) were calculated by the aid of the Force-Crack Mouth Open Displacement curves and the relevant analytical equations.

scholarly journals Guide for Recommended Practices to Perform Crack Tip Opening Displacement Tests in High Strength Low Alloy Steels

2016 ◽  
Vol 21 (3) ◽  
pp. 290-302 ◽  
Author(s):  
Julián A. Ávila ◽  
Vinicius Lima ◽  
Cassius O. F. T. Ruchert ◽  
Paulo Roberto Mei ◽  
Antonio J. Ramirez
Keyword(s):  
Crack Tip ◽  
High Strength ◽  
Low Alloy Steels ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Alloy Steels ◽  
Recommended Practices ◽  
Crack Tip Opening

scholarly journals MICRO-CRACK ANALYSIS IN THE STUDY OF FATIGUE FRACTURE IN THE HAZ IN THE HIGH YIELD STRENGTH MICRO-ALLOYED STEELS

10.6036/10139 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 46-52
Author(s):  
MANUEL VISERAS ◽  
RAFAEL ERNESTO GONZALEZ PALMA ◽  
MARIA DEL CARMEN CARNERO MOYA ◽  
MANUEL TORNELL BARBOSA
Keyword(s):  
Fracture Toughness ◽  
Fatigue Fracture ◽  
Weld Line ◽  
High Strength ◽  
High Yield ◽  
Low Alloy Steels ◽  
Crack Tip Opening Displacement ◽  
Successful Operation ◽  
Opening Displacement ◽  
Summary Table

Various applications have been described in the literature for the High-Strength and Low-Alloy steels (HSLA) industry, analysing their use both in industrial and marine equipment and machines and in structures that require appropriate resilience values and toughness at low temperatures. For successful operation under conditions as large structures under extreme service conditions, it is essential to ensure the proper toughness both in base metal (USITEN 355 0.5 Ni Grade I steel) and in the heat-affected area of the weld. (ZAC). This research carries out Crack Tip Opening Displacement (CTOD) tests, showing, in this article, the first part of the test corresponding to fatigue pre-cracking and a summary table of the results of fracture toughness, to guarantee that, under the conditions which exist in welding, both the fatigue fracture values and the fracture toughness are acceptable by the applicable standards. Keywords: SMAW, weld line, CTOD, stress intensity factor, input heat energy, crack growth rate, fatigue fracture, fracture toughness

TRI-MARK TM-115

Alloy Digest ◽  
1983 ◽  
Vol 32 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Arc Welding ◽  
High Strength ◽  
Heat Treating ◽  
Low Alloy Steels ◽  
Mining Equipment ◽  
Alloy Steels ◽  
Temperature Impact ◽  
Welding Electrode

Abstract TRI-MARK TM-115 is a gas-shielded flux-cored welding electrode for continuous high deposition are welding. It is designed specifically for semiautomatic and automatic arc welding of high-strength low-alloy steels and quenched-and-tempered steels. This gas-sheilded tubular wire can be used for single and multiple-pass welding. It has outstanding low-temperature impact properties. Its applications including mining equipment, large vehicles and similar items. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-392. Producer or source: Tri-Mark Inc..

scholarly journals Influence of the Welding Process on the Mechanical Characteristics and Fracture of the S700MC High Strength Steel under Various Types of Loading

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5249
Author(s):  
Tadeusz Szymczak ◽  
Katarzyna Makowska ◽  
Zbigniew L. Kowalewski
Keyword(s):  
Fracture Toughness ◽  
Welding Process ◽  
High Strength ◽  
Mechanical Tests ◽  
Parent Material ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Joint Stress ◽  
Characteristic Features ◽  
The Impact

This paper focuses on the mechanical properties analysis of the high strength S700MC steel applied in welding joints. The research comprised mechanical tests for checking what the changes of tensile characteristics, mechanical parameters, resistance to impact, and fracture toughness look like in selected regions of the welding joint. Stress-strain curves have shown significant differences in the tensile characteristic shape and the values of Young’s modulus, yield stress, ultimate tensile strength, and ductility due to the welding process applied. In the case of Charpy tests, the courses of the accumulated energy, force, deflection, and project velocity are presented, indicating the maximum value of absorbed energy, the same level of force during the first contact of the projectile with the specimens, and the significant variation of the velocity for the impact energy ranging from 50 J up to 300 J. On the basis of the fracture toughness tests, the distributions of the CTOD (Crack Tip Opening Displacement) values are presented for the parent material, HAZ (Heat Affected Zone) and weld. Moreover, the characteristic features of the fatigue pre-crack, transient and crack propagation zones are identified and discussed.

In Situ Neutron Diffraction during Thermo-Mechanically Controlled Process in Low Alloy Steels

2006 ◽  
Vol 118 ◽  
pp. 419-424
Author(s):  
M.S. Koo ◽  
Ping Guang Xu ◽  
J.H. Li ◽  
Yo Tomota ◽  
O. Muransky ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Volume Fraction ◽  
Structural Evolution ◽  
Low Alloy Steels ◽  
Controlled Processing ◽  
Ferrite Transformation ◽  
Alloy Steels ◽  
Time Division ◽  
In Situ Neutron Diffraction

A challenge was made to examine the micro-structural evolution during thermomechanically controlled processing (TMCP) by in situ neutron diffraction. Since the neutron beam is too weak to achieve a time-division measurement to follow a rapid transformation in alow carbon steel, 2%Mn was added to make the austenite to ferrite transformation slower. Round bar specimens were heated up to 900°C with an electrical resistance method, then cooled down to 700°C, and compressed by 25% followed by step-by-step cooling. During the step-by-step cooling, neutron diffraction profiles were obtained and the volume fraction of ferrite, phase stresses and FWHM were analyzed. Using a similar TMCP simulator, specimens were quenched into water at several stages of the heat schedule to freeze the corresponding microstructures, which were observed with OM and SEM. As results, the ferrite volume fraction determined by neutron diffraction on cooling agrees well with that by microscopy. It is found that the austenite deformation and/or Nb addition accelerate the ferrite transformation to result in finer grain size.

Sign in / Sign up

Export Citation Format

Share Document