Properties Of Low Carbon Research Articles

Crack Width Control and Mechanical Properties of Low Carbon Engineered Cementitious Composites (Ecc)

Crack Width Control and Mechanical Properties of Low Carbon Engineered Cementitious Composites (Ecc)

The Microstructure and Properties of Low Carbon PM 625 Alloy for Marine-Based Application

The low carbon content powder metallurgy (PM) 625 alloy were manufactured by vacuum induction gas atomization (VIGA) and hot isostatically pressing (HIP) for marine-based application such as parts in the subsea Xmas tree. Corrosion experiment was performed in simulated deep seawater and subsea oil & gas service environment. The microstructures and properties of low carbon 625 alloy were comparably investigated with that of the as-cast alloy. The results indicated that the dendritic arm spacing (DAS) of the as-cast 625 alloy is 2 orders of magnitude higher than that of the powders, whereas the HIPed alloys possess a fine equiaxed grain structures without dendritic segregation and an average grain size of 14.5μm. No minor phase has been found beside the γ matrix in the original powders with different particle size. The tensile strength of low carbon PM 625 alloy is 26% higher than that of as-cast 625 alloy. PM 625 alloy possesses an excellent corrosion resistant in simulated deep seawater and oil & gas service environment for 30 days.

Study of Features of Phase Precipitate Formation, Structural State, and Properties of Nb, V-Microalloyed Low Carbon Ferritic Steels

Contemporary methods of optical and transmission electron microscopy, and mechanical property tests are used to study features of phase precipitate formation, structural state, and the properties of lowcarbon V, Nb micro-alloyed steels. The effect of nano-sized carbide (carbonitride) V, Nb precipitates formed in austenite during FCC → BCC-phase transformation of steel on the structural state and implementation of different mechanisms is evaluated. Characteristics of similar Ti and Mo precipitates in micro-alloyed ferritic steels are compared.

Transformation Behavior and Properties of Carbide‐Free Bainite Steels with Different Si Contents

The bainite transformation behavior and properties of low carbon carbide‐free bainitic steels containing different silicon (Si) contents are investigated by two different types of heat treatment processes: isothermal transformation process (ITP) and continuous cooling process (CCP). The results indicate that for ITP and CCP, the transformation kinetics of bainite is retarded and the final bainite amount decreases with increasing Si content. However, both the strength and total elongation improve with the increase of Si content in the range of 1.0–2.0 wt%, resulting in an apparent increment in comprehensive property of bainitic steels due to the more film‐like RA and less carbides. It can be attributed to the increase of shear strength and stability of undercooled austenite and the formation of Cottrell atmosphere, as well as the solid solution strengthening of Si because of higher Si content. In addition, for the same samples, better mechanical properties can be achieved by a lower austempering temperature. Moreover, the increase of Si content resulted in an increase in the temperatures of Ac1 and Ac3.

Effect of quench and strain aging on the mechanical properties of low carbon microalloyed steels

Abstract In this study, the aging behaviors of high strength low alloyed (HSLA) HC380LA quality steel were investigated. Steel samples were heated in a heat treatment furnace up to 950 °C and kept there for 1 hour, and then quenched in water. Some of the water quenched samples were aged at temperatures between 50–350 °C for 20 min (quench-aged, QA), while the other samples were exposed to the same aging procedure after a 3 % prestraining (strain-aged, SA). Experimental results showed that aging occurred in all QA and SA samples. The highest values for both QA and SA samples were obtained at aging treatment performed at 150 °C for 20 min. When the aging temperature increased to 200, 250, 300 or 350 °C, aging strength decreased. Results of the study suggest that different aging temperatures have an effect on the microstructure and on the mechanical properties of high strength low alloyed steels.

Low carbon high manganese bainitic steel

The present study concerns the mechanical properties of low carbon (0·05 wt-%) high Mn bainitic steel. The continuous cooling transformation diagram exhibited bainitic transformation without any prior diffusive transformation of austenite even for a cooling rate as low as 0·5°C/s. The bainitic steels have shown continuous elongation behaviour with attractive combination of strength (>1200 MPa) and elongation (>14%). The bainitic microstructure obtained after annealing treatment has yielded excellent combination of strength, uniform elongation, yield ratio and static toughness value.

Effect of Mo and Ni Content on the Mechanical Properties of Low Carbon and Alloy Steel Casting Sample for Coal-Mining Machinery

The effect of Mo and Ni content on the mechanical properties of low carbon and alloy casting steel by using Vacuum Arc Melting Furnace had been studied in this paper. The results indicated that increasing Mo or Ni content would enhance the hardness and strength of the steel separately, with some of elongation loss. It showed that ferrite refined with the increasing alloy content. The combinations of Mo and Ni content were of importance for comprehensive mechanical properties and wear resistance. The appropriate content in low carbon casting steel with 0.02%Nb was 0.5%-0.6%Mo and 0.2%-0.4%Ni.

Microstructure and Mechanical Properties of Low Carbon Al-Killed Steels after Ultra-Rapid Annealing Cycles

Ultra rapid annealing cycles were conducted on two low carbon Al-killed steel sheets differing mainly by their coiling temperatures (600°C or 700°C). For the lowest coiling temperature, the mean grain size of the steel was found to gradually decrease with an increase of the annealing temperature from 700°C to 920°C. A more complex grain size evolution was detected in the case of the steel coiled at high temperature. This led us to the conclusion that the size and the distribution of the iron carbides present before annealing, which is mainly governed by the coiling temperature, plays a very important role on the mechanisms involved in the grain refinement of extra-mild steels during ultra-rapid annealing cycles.

Effect of impact energy on the impact-wear properties of low carbon high manganese alloy steels in corrosive conditions

Effect of impact energy on the impact-wear properties of low carbon high manganese alloy steels in corrosive conditions

Effects of vanadium and titanium on mechanical properties of low carbon as cast microalloyed steels

Tensile, hardness and room temperature Charpy V notch impact tests were conducted to evaluate the variations in the mechanical properties of a low carbon cast steel containing vanadium and combinations of vanadium and titanium in the as cast condition. Tensile and hardness test results indicated that good combinations of strength and ductility can be achieved by microalloying additions. The effect of titanium on the yield strength and hardness, however, strongly depended on Ti/N ratio. Ti in hyperstoichiometric amounts increased the yield strength and hardness whereas in hypostoichiometric amounts, it did not have a considerable effect on those properties. Scanning electron microscopy and optical microscopy studies revealed that coarse TiN particles were responsible for this behaviour. On the other hand, microalloying additions significantly decreased the room temperature impact energy and led to the dominance of cleavage facets on the fracture surfaces. Although coarse TiN particles were identified to act as cleavage nucleation sites in the Ti bearing heats, no distinct microstructural feature could be identified as cleavage initiators in the microstructure of the alloy containing only vanadium.

Effects of Thermo-Mechanical Process on the Microstructure and Mechanical Properties of Low Carbon HSLA Steels

Effects of deformation at austenite region and cooling rate on the microstructure and mechanical properties of low carbon (0.06 wt. % C) high strength low alloy steels have been investigated. Average grain size decreased and polygonal ferrite transformation promoted with increasing deformation amount at austenite region due to increase of ferrite nucleation site. Microstructure was also influenced by cooling rate resulting in the development of a mixture of fine polygonal ferrite and acicular ferrite at 10°C/s cooling rate. Discontinuous yielding occurred in highly deformed specimen due to the formation of polygonal ferrite. However, small grain size of highly deformed specimen caused lower ductile-to-brittle transition temperature than slightly deformed specimen.

The Mechanical Properties of Low Carbon High Manganese Microalloyed Steels

The Mechanical Properties of Low Carbon High Manganese Microalloyed Steels

Effect of addition of rare earth metal on hot tensile properties of low carbon, low alloy martensite

AbstractThe effects of the addition of rare earth metal (REM) on the stress relief cracking susceptibility of low alloy martensite have been examined by slow strain rate tensile tests. The partial dissolution of MnS by austenitization before quenching at temperatures as high as 1573 K promoted the intergranular decohesive mode of fracture in hot tensile tests, and the stabilization of free S atoms by the addition of REM increases ductility at temperatures between 823 and 890 K and the fracture morphology changes to that of intergranular microvoid coalescence. However, in higher temperature deformation in the range from 890 to 973 K, the addition of REM reduces ductility and increases the fraction of intergranular microvoid coalescence at the expense of the transgranular ductile fracture mode. This can be explained in terms of AlN precipitation in relation to the dispersion of fine MnS particles.