The isothermal diagram of transformation of the residual austenite by tempering

1993 ◽  
Vol 24 (12) ◽  
pp. 2806-2810
Author(s):  
Bertold Vinokur
Keyword(s):  
Residual Austenite ◽  
Isothermal Diagram

Effect of the Heat Input in the Transformation of Retained Austenite in Advanced Steels of Transformation Induced Plasticity (TRIP) Welded with Gas Metal Arc Welding

2013 ◽  
Vol 339 ◽  
pp. 700-705 ◽  
Author(s):  
Victor Lopez ◽  
Arturo Reyes ◽  
Patricia Zambrano
Keyword(s):  
Heat Input ◽  
Arc Welding ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Residual Austenite ◽  
Welding Parameters ◽  
Transformation Induced Plasticity ◽  
Metal Arc Welding

The effect of heat input on the transformation of retained austenite steels transformation induced plasticity (TRIP) was investigated in the heat affected zone (HAZ) of the Gas Metal Arc Welding GMAW process. The determination of retained austenite of the HAZ is important in optimizing the welding parameters when welding TRIP steels, because this will greatly influence the mechanical properties of the welding joint due to the transformation of residual austenite into martensite due to work hardening. Coupons were welded with high and low heat input for investigating the austenite transformation of the base metal due to heat applied by the welding process and was evaluated by optical microscopy and the method of X-Ray Diffraction (XRD). Data analyzed shows that the volume fraction of retained austenite in the HAZ increases with the heat input applied by the welding process, being greater as the heat input increase and decrease the cooling rate, this due to variation in the travel speed of the weld path.

scholarly journals Effects of robotic CO2 arc welding variables on penetration and microstructure of weld in C-80 grade steel

2010 ◽  
Vol 7 (1) ◽  
pp. 67-75
Author(s):  
Hamid Reza Ghazvinloo ◽  
Abbas Honarbakhsh-Raouf ◽  
Nasim Shadfar
Keyword(s):  
Weld Metal ◽  
Cross Sections ◽  
Arc Welding ◽  
Welding Process ◽  
Welding Current ◽  
Residual Austenite ◽  
Martensite Phase ◽  
Optical Observations ◽  
Bead Geometry ◽  
Steel Joints

Generally, the quality and properties of a weld joint is strongly influenced by welding variables during process. In order to achieve an ideal weld, it is important attention to bead geometry and microstructure evolution of weld metal. The effect of process variables on penetration and microstructure of C-80 steel joints produced by robotic CO2 arc welding was studied in present work. Different samples were produced by employing arc voltages of 23, 25 and 27 V, welding currents of 100, 110 and 120 A and welding speeds of 42, 62 and 82 cm/min. After welding process, geometric measurements were performed on welding specimens and the microstructural evolutions were investigated by optical observations of the weld cross sections. Results were clearly illustrated that increasing in welding current or arc voltage increases the depth of weld penetration. The highest penetration in this research was observed in 62 cm/min welding speed. The metallographic examinations also indicated that the microstructure of weld metal in all of specimens was composed mainly of martensite (M) and residual austenite (A) phases that a portion of martensite phase had been tempered.

Microstructures and Properties of a Bainite and Martensite Dual-Phase Cast Steel Fabricated by Combination of Alloying and Controlled Cooling Heat Treatment

2005 ◽  
Vol 475-479 ◽  
pp. 93-96 ◽  
Author(s):  
Ye Hua Jiang ◽  
Rong Feng Zhou ◽  
Dehong Lu ◽  
Zhen Hua Li
Keyword(s):  
Heat Treatment ◽  
Cast Steel ◽  
Residual Austenite ◽  
Lower Bainite ◽  
Manganese Steel ◽  
Isothermal Quenching ◽  
Dual Phase ◽  
Controlled Cooling ◽  
Carbide Particles ◽  
Better Than

A bainite/martensite dual-phase cast steel was fabricated by a process of combination of alloying with Si and Mn elements and controlled cooling heat-treatment. Its microstructure was consisted of fine lower bainite with carbide particles precipitated homogeneously, martensite and a little residual austenite. Because of the good match of hardness and impact toughness, its impact wear performance was a little better than that of the isothermal quenching steel, and much better than that of high manganese steel such as Mn13.

Comportement au revenu d'un acier du type Z80CDSV8.2.1.1 pour cylindres de laminoirs à chaud

1996 ◽  
Vol 84 ◽  
pp. 3-12
Author(s):  
H. Djebaïli
Keyword(s):  
Magnetic Measurements ◽  
Residual Austenite ◽  
Progressive Increase ◽  
Continuous Heating ◽  
Preliminary Treatment ◽  
Hardness Testing ◽  
Physical Methods ◽  
The Matrix ◽  
Primary Carbides ◽  
Hot Hardness

Transformations in Cr-Mo-Si steels with a specific addition of Vanadium have been characterized precisely as well as their effect on the hardness of the materials. A preliminary treatment in the austenitic field leads to a limited enrichment of the matrix as well as temperature is less than 1050°C : only M3C and M23C6 carbides may then be dissolved. On the contrary, the dissolution of M7C3 and MC carbides is observed over 1100°C but is only partial even after treatment at 1150°C. After quenching from three distinct temperatures (1050-1100 and 1150°C), the microstructure consists of martensite, residual austenite and primary carbides (mainly M7C3 and MC type) ; different tempering treatments have been performed (isochronal, isothermal or on continuous heating) using various physical methods (dilatometry, DTA and magnetic measurements, TEM observations and hot hardness testing). According to the maximum θR temperature reached, the following structural evolutions were observed :•ε carbide precipitates at θR < 250° C in the a’ matrix, then M3C carbide forms between 250 and 350°C which transforms in M7C3 carbide from 450 to 500°C. At the same time (300- 500°C) a secondary hardening occurs linked to the formation of very fine V4C3 carbides : a progressive increase in hot hardness is observed while holding isothermally at 300-450°C.•From 450 to 600°C, the residual austenite is destabilized owing to the precipitation of small carbides in α'/γ interfaces and may be transformed on cooling either in bainite or secondary martensite. On the other hand that impoverished austenite may be transformed in (α + carbides) between 600-700°C. Besides in the same temperature range, M6C and M23C6 may be formed at the expense of fine M7C3 carbides previously formed.

Carbon Enrichment in Residual Austenite during Martensitic

ICOMAT ◽  
2013 ◽  
pp. 179-185 ◽  
Author(s):  
S. W. Ooi ◽  
Y. R. Cho ◽  
J. K. Oh ◽  
H. K. D. H. Bhadeshia
Keyword(s):  
Residual Austenite

Effect of Particular Combinations of Quenching, Tempering and Carburization on Abrasive Wear of Low-Carbon Manganese Steels with Metastable Austenite

2019 ◽  
Vol 945 ◽  
pp. 574-578 ◽  
Author(s):  
L.S. Malinov ◽  
I.E. Malysheva ◽  
E.S. Klimov ◽  
V.V. Kukhar ◽  
E.Y. Balalayeva
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Residual Austenite ◽  
Abrasive Wear Resistance ◽  
Low Carbon ◽  
Metastable Austenite ◽  
Carbon Manganese Steels ◽  
The Impact ◽  
Manganese Steels ◽  
Dynamic Ratio

The effect of quenching from 900°C (20 min exposure) and different tempering in the 250-650°C (for 1 hour) interval, as well as additionally preliminary carburization for 8 hours at 930°C, followed by a similar heat treatment on abrasive and shock-abrasive wear of low-carbon manganese (10-24%Mn) steels, phase composition and mechanical properties was studied. It was confirmed that an increase in the manganese reduces the abrasive wear resistance and increases the impact-abrasive wear resistance. The expediency of carburization of low-carbon manganese steels is shown in order to obtain the residual austenite in the structure which amount and stability must be optimized in relation to specific abrasive impact characterized by the dynamic ratio with taking into account the chemical composition.

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