THE DESIGN OF THE LOW-CARBON MARTENSITIC STRUCTURAL STEEL FOR HIGH STRENGTH AND TOUGHNESS AND ITS STRUCTURE-PROPERTY RELATIONS

1982 ◽  
Vol 43 (C4) ◽  
pp. C4-417-C4-422
Author(s):  
Wang Xiao-tian ◽  
Tan Yu-xu ◽  
Yang Bao-shen ◽  
Cheng Zhen
Keyword(s):  
Structural Steel ◽  
High Strength ◽  
Low Carbon ◽  
Structure Property ◽  
Property Relations ◽  
Strength And Toughness

A New Approach Using EBSD to Quantitatively Distinguish Complex Transformation Products Along the HAZ in X80 Linepipe Steel

2014 ◽  
Author(s):  
Jennifer M. Reichert ◽  
Matthias Militzer ◽  
Warren J. Poole ◽  
Laurie Collins
Keyword(s):  
Orientation Relationship ◽  
Transformation Temperature ◽  
Retained Austenite ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Transformation Products ◽  
Carbon Steels ◽  
Low Carbon ◽  
Structure Property ◽  
Linepipe Steel

State-of-the-art linepipe steels are microalloyed low-carbon steels that combine high strength and fracture toughness with good weldability. During welding of pipe sections the heat affected zone (HAZ) experiences rapid thermal cycles resulting in a graded microstructure that can be significantly different from that of the base metal. In particular a variety of bainitic microstructures can form in the HAZ. Depending on the type of bainite mechanical properties may be improved or may lead to poor fracture resistance and be detrimental to the overall HAZ performance. Optical microscopy is not sufficient to differentiate bainitic morphologies which vary with the transformation temperature. The investigated X80 linepipe steel also contains retained austenite at room temperature. Based on the retained austenite it is possible to characterize the orientation relationship (OR) between austenite and the transformation products. It is found that bainite shows an orientation relationship near Kurdjumov-Sachs with the prior austenite. Variant selection is related to the driving force for the bainite reaction and hence depends on the transformation temperature. In the current study Electron BackScatter Diffraction (EBSD) mapping is used to characterize transformation products based on their orientation relationship. This approach offers a quantitative way to determine volume fractions of different types of bainite in complex HAZ microstructures which is necessary to establish structure-property relationships of the HAZ.

Mechanics of Strong and Tough Cellulose Nanopaper

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Qinghua Meng ◽  
Tie Jun Wang
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Material Design ◽  
Design Strategy ◽  
Mechanical Modeling ◽  
Structure Property ◽  
Porous Network ◽  
Cellulose Nanopaper ◽  
Strength And Toughness

Cellulose nanopaper, which consists of a porous network of cellulose nanofibrils (CNFs), exhibits excellent mechanical properties with high strength and toughness. The physical mechanisms, including a realizable reduction of defect size in the nanopaper and facile formation/reformation of hydrogen bonds among CNFs, suggest a bottom-up material design strategy to address the conflict between strength and toughness. A thorough exploration of the rich potential of such a design strategy requires a fundamental understanding of its mechanical behavior. In this review, we supply a comprehensive perspective on advances in cellulose nanopaper mechanics over the most recent two decades from the three aspects of mechanical properties, structure–property relationship and microstructure-based mechanical modeling. We discuss the effects of size, orientation, polymerization degree, and isolate origins of CNFs; density or porosity and humidity of nanopaper; and hemicellulose and lignin on the mechanical properties of cellulose nanopaper. We also discuss the similarities and differences in the microstructure, mechanical properties, and toughening mechanisms between cellulose nanopaper and cellulose nanocrystal (CNC) nanopaper, chitin nanopaper, carbon nanotube (CNT) nanopaper, and graphene nanopaper. Finally, we present the ideas, status quo, and future trends in mechanical modeling of cellulose nanopaper, including atomistic- and microscale-level numerical modeling, and theoretical modeling. This review serves as a modest spur intended to induce scientists to present their valuable contributions and especially to design more advanced cellulose nanopapers and promote the development of their mechanics.

Electron Microscope studies of the microstructures in as-quenched and aged HSLA-100 production steels and correlation with mechanical properties

1991 ◽  
Vol 49 ◽  
pp. 582-583
Author(s):  
A.G. Fox ◽  
V.R. Mattes ◽  
S. Mikalac ◽  
M.G. Vassilaros
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Solid Solution Strengthening ◽  
Austenite Grain ◽  
Microstructure And Mechanical Properties ◽  
Hsla Steels ◽  
Carbonitride Precipitation ◽  
Strength And Toughness

Because of their excellent weldability, high strength low alloy (HSLA) ultra low carbon bainitic (ULCB) steels are finding increasing applications in ship and submarine construction. In order to achieve the required strength and toughness in ULCB HSLA steels it is necessary to control chemical composition and thermo-mechanical processing very carefully so that the desired microstructure and mechanical properties can be achieved. For instance HSLA 100 ULCB steel (nominal yield strength 100 ksi) used by the U.S. Navy in shipbuilding applications can derive its strength and toughness from the following sources:- (1) solid solution strengthening (2) small prior austenite grain size derived from niobium carbonitride precipitation at austenite grain boundaries (3) dislocation substructure and (4) from copper precipitates (in aged alloys). The object of the present work is to correlate the microstructure and mechanical properties of production batches of HSLA 100 in the quenched and aged conditions. Because many of the salient features of these microstructures are submicron in size it was found necessary to use SEM and TEM.

BISALLOY STRUCTURAL 60

Alloy Digest ◽  
2019 ◽  
Vol 68 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Shear Strength ◽  
Low Temperature ◽  
Yield Strength ◽  
Structural Steel ◽  
High Strength ◽  
Low Carbon ◽  
Temperature Fracture ◽  
Minimum Yield

Abstract Bisalloy Structural 60 steel (60 ksi minimum yield strength) is a low-carbon, low-alloy, high-strength structural steel exhibiting excellent cold formability and low-temperature fracture toughness. This datasheet provides information on composition and shear strength. It also includes information on forming and joining. Filing Code: SA-839. Producer or source: Bisalloy Steels Group Limited.

LUCEFIN 25CrMo4 (1.7218), 25CrMoS4 (1.7213)

Alloy Digest ◽  
2021 ◽  
Vol 70 (8) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Small Section ◽  
Section Size ◽  
Alloy Steels ◽  
Strength And Toughness

Abstract Lucefin 25CrMo4 and 25CrMoS4 are low-carbon, chromium-molybdenum direct hardening alloy steels. These low hardenability steels are used for water-quenched parts of moderate section size and for oil-quenched parts of small section size. In general, these steels are used for parts requiring high strength and toughness. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-874. Producer or source: Lucefin S.p.A.

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