Factors Affecting the Susceptibility of Carbon-Manganese Steel Welds to Cracking in Sour Environments

2009 ◽  
pp. 169-169-71
Author(s):  
RJ Pargeter
Keyword(s):  
Manganese Steel ◽  
Factors Affecting ◽  
Steel Welds

scholarly journals Comprehensive Analysis of Cold-Cracking Ratio for Flux-Cored Arc Steel Welds Using Y- and y-Grooves

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5349
Author(s):  
Hyunbin Nam ◽  
Jaeseok Yoo ◽  
Kwanghee Yun ◽  
Guo Xian ◽  
Hanji Park ◽  
...  
Keyword(s):  
Hydrogen Content ◽  
High Strength ◽  
Cold Cracking ◽  
Carbon Equivalent ◽  
Diffusible Hydrogen ◽  
Factors Affecting ◽  
Strength Grade ◽  
Groove Shape ◽  
Weld Metals ◽  
Steel Welds

This study investigates various factors that influence the cold-cracking ratio (CCR) of flux-cored arc welds through Y- and y-groove tests. Factors affecting the CCR include the alloy component, diffusible hydrogen content, microstructure, hardness, and groove shape. In weld metals (WMs; WM375-R and WM375-B) of a low-strength grade, the diffusible hydrogen content has a more significant effect on the CCR than the carbon equivalent (Ceq) and microstructure. However, the combined effects of the microstructure and diffusible hydrogen content on the CCR are important in high-strength-grade WM. The CCR of the WM increased upon increasing Ceq and the strength grade because hard martensite and bainite microstructures were formed. Moreover, y-groove testing of the 500 MPa grade WM revealed a more significant CCR than that of the 375 MPa grade WM. Therefore, in high-strength-grade WMs, it is necessary to select the groove shape based on the morphology in the real welds.

Investigation of Correlation Between Fracture Toughness and Charpy Impact Energy of Cryogenic Steel Welds

2021 ◽  
Vol 21 (9) ◽  
pp. 4921-4925
Author(s):  
Gyubaek An ◽  
Seunglae Hong ◽  
Jeongung Park ◽  
Ilwook Han
Keyword(s):  
Fracture Toughness ◽  
Charpy Impact ◽  
Manganese Steel ◽  
Unique Element ◽  
Crack Tip Opening Displacement ◽  
High Manganese ◽  
Opening Displacement ◽  
High Manganese Steel ◽  
Steel Welds ◽  
Cryogenic Steel

The high manganese steel was developed to improve the fracture toughness and safety at cryogenic temperatures, the austenite structure was formed by increasing the manganese (Mn) content. The developed weld high manganese steel was alloyed with austenite stabilizing elements (e.g., C, Mn, and Ni) for cryogenic toughness and fluxes contained less than 10% of acidic slag formers such as rutile (TiO2) and silica (SiO2). This paper describes the work carried out to enhance the fracture toughness of Mn contents in an economical way by means of increase of manganese up to 23% instead of using nickel (Ni) which has unique element to improve fracture toughness especially at cryogenic steel. The new cryogenic steels should be carefully evaluated in terms of safety for application in real structures including LNG ships. In this study, the fracture toughness performance was evaluated for recently developed cryogenic steels (high-Mn steels), especially the crack tip opening displacement (CTOD) parameter was evaluated using the prediction formula proposed by conventional equation. The CTOD value was investigated the effect of microstructure and mechanical properties of Fe–C–Mn and Fe–C–Mn–Ni high manganese steel, it was revealed that the e-martesnsite phase formed in high manganese steel of 0.2C–20Mn and 0.4C–20Mn as a result of a low stability of austenite upon strain-induced phase transformation.

Oxide Formation Mechanisms in High Manganese Steel Welds

2013 ◽  
Vol 45 (4) ◽  
pp. 2046-2054 ◽  
Author(s):  
Dooyoung Kim ◽  
Kyutae Han ◽  
Bongkeun Lee ◽  
Ilwook Han ◽  
Joo Hyun Park ◽  
...  
Keyword(s):  
Manganese Steel ◽  
Formation Mechanisms ◽  
Oxide Formation ◽  
High Manganese ◽  
High Manganese Steel ◽  
Steel Welds

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Factors affecting microstructural scale in liquid crystalline polymers

1990 ◽  
Vol 48 (4) ◽  
pp. 220-221
Author(s):  
Christine M. Dannels ◽  
Christopher Viney
Keyword(s):  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Factors Affecting ◽  
Crystalline Polymers ◽  
Thermal Expansion Coefficients ◽  
Low Thermal Expansion ◽  
Lower Viscosity ◽  
Fine Microstructure ◽  
Planar Orientation ◽  
Strength And Stiffness

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.

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