Study of Direct Quenching and Tempering Process of a Low Carbon Equivalent 960 MPa Grade Steel

2013 ◽  
Vol 744 ◽  
pp. 329-333
Author(s):  
Feng Lu ◽  
Chao Wang ◽  
Yuan Yuan Li ◽  
Long Lu ◽  
Zhao Dong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lath Martensite ◽  
Controlled Rolling ◽  
Carbon Equivalent ◽  
Low Carbon ◽  
Tempering Temperature ◽  
Experimental Steel ◽  
Direct Quenching ◽  
Quenching And Tempering ◽  
Tempering Process

The chemical composition of a 960 Mpa grade high strength steel with low carbon equivalent was designed. Effect of direct quenching and tempering process on the microstructure and mechanical properties of the experimental steel was studied. Results showed that fine lath martensite was obtained after controlled rolling and direct quenching. With tempering temperature increasing, the mechanical properties showed different trends for different tempering stages. And this had a direct relationship with the microstructure evolution. The matrix recovery softening, carbon desolution and precipitation of nanomicroalloy carbides influenced the strength change. With increase of tempering time, the strength decreased and toughness improved. Experimental steel tempered at 450 °C for 40min could obtain the best mechanical properties, which meet the requirement with a large impact energy margin.

Effects of direct-quenching and tempering on the microstructure and mechanical properties of an ultra-low carbon Ti containing bainite steel

2020 ◽  
Vol 796 ◽  
pp. 139987
Author(s):  
Peng Pan ◽  
Hao Tang ◽  
Xiaohua Chen ◽  
Zidong Wang ◽  
Lingli Zuo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Carbon ◽  
Direct Quenching ◽  
Microstructure And Mechanical Properties ◽  
Bainite Steel ◽  
Quenching And Tempering

Microstructures and Mechanical Properties of Tough Ductile Ultrahigh-Strength Steels Processed through Direct Quenching and Partitioning

2018 ◽  
Vol 941 ◽  
pp. 468-473 ◽  
Author(s):  
Pekka K. Kantanen ◽  
Mahesh C. Somani ◽  
David A. Porter ◽  
Jukka I. Kömi ◽  
Devesh K. Misra
Keyword(s):  
Mechanical Properties ◽  
Lath Martensite ◽  
Controlled Rolling ◽  
Processing Route ◽  
Direct Quenching ◽  
Ultrahigh Strength ◽  
Microstructures And Mechanical Properties ◽  
Hot Strip Mills ◽  
Low Temperature Impact Toughness ◽  
Ultrahigh Strength Steels

Using a novel TMR-DQP processing route, two ultrahigh-strength steels have been developed with yield strengths up to 1100 MPa combined with good uniform and total elongations and low-temperature impact toughness. Processing involved thermomechanically controlled rolling including significant reductions below the recrystallization stop temperature (RST), subsequent direct quenching to desired quench stop temperatures between Ms and Mf and finally partitioning of carbon from the supersaturated martensite to the untransformed austenite in a furnace at the quench stop temperature. Samples were cooled slowly in the furnace over 50 hours to simulate the cooling of coiled strips on industrial hot strip mills. The approach used was to utilize a suitable 0.3C steel composition based on high silicon and/or aluminium contents. Detailed metallographic studies using LOM, FESEM-EBSD, TEM and XRD showed that the desired martensite-austenite microstructures were achieved. The advantage of strained austenite in respect of refinement of martensite packets/blocks was clearly evident. Austenite was finely divided between martensite laths and only an insignificant amount of austenite existed as pools. The fine lath martensite structure with narrow interlath retained austenite films enabled the achievement of excellent combinations of mechanical properties. Promising results in respect of microstructures and mechanical properties indicate that there are possibilities for developing tough ductile structural and abrasion-resistant steels through the TMR-DQP route.

The Tempering on Microstructure and the Yield-to-Tensile Ratio of High Performance Steels

2012 ◽  
Vol 535-537 ◽  
pp. 655-658
Author(s):  
Xue Min Wang ◽  
Hui Zhao
Keyword(s):  
High Performance ◽  
Lath Martensite ◽  
Yield Ratio ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Considerable Influence ◽  
Austenitic Phase ◽  
Tempering Temperature ◽  
Low Temperature Toughness ◽  
Tempering Process

The effects of tempering temperature on the microstructure and mechanical properties of 600MPa grade low carbon bainitic steel were investigated. The cause for the microstructure evolution has been investigated and the best tempering process was chosen to decrease the yield ratio of the steel. The influence of tempering process on the yield-to-tensile ratio of steels has been investigated by the aid of optical microscopy, SEM and XRD. The results show that after the TMCP processing the microstructure of steels mainly consist of lath martensite and bainite. The bainite and martensite have been refined markedly after the relaxation processing, therefore the properties of steels has been improved evidently. In order to decrease the yield-to-tensile ratio the steels underwent high temperature tempering. It has been found that during the tempering with the tempering temperature increased the yield-to-tensile ratio of steels decreased. The XRD and EBSD results show tempering temperature has considerable influence on the yield strength, but the influence on the tensile strength is not considerable. With the increase in tempering temperature, the low temperature toughness of steel can be improved considerably. The yield ratio of the steel was reduced after tempering at 650 °C and higher temperatures due to reversed austenitic phase transformation.

Development of Direct Quenching Process for SPV490Q Steel Plate

2011 ◽  
Vol 197-198 ◽  
pp. 757-761
Author(s):  
Gui Zhi Xiao ◽  
Kuai She Wang ◽  
Fu Xian Zhu ◽  
Hong Shuang Di
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Steel Plate ◽  
Lath Martensite ◽  
Rolling Direction ◽  
Steel Plates ◽  
Low Carbon ◽  
Direct Quenching ◽  
Oil Storage ◽  
Quenching Process

SPV490Q steel is a low alloy high strength structural steel plate used in the manufacture of oil storage tank. To improve the comprehensive performance of SPV490Q steel plate and reduce manufacturing costs, direct quenching technology has been developed as revolutionary plate manufacturing technologies in recent years. Effect of direct quenching on microstructure and mechanical properties of high performance SPV490Q steel plate has been studied. The direct quenched (DQ) steel plates are rolled at different finish rolling temperatures, and their microstructures and mechanical properties are compared with those of reheat quenched (RQ) steel plate. The optical microstructure of the DQ steel shows deformed grains elongated parallel to the rolling direction, while complete equiaxed grains are visible in RQ steel. The transmission electron microscope (TEM) microstructure of the DQ steel shows refined lath martensite with high density of dislocations. The findings indicate that the application of the direct quenching process to low-carbon alloy steels contributes to the production of steel plates with excellent strength and toughness.

Heat Treatment of 10Cr12Ni3Mo2VN Blade Steel for Ultra Supercritical Unit

2015 ◽  
Vol 817 ◽  
pp. 472-478
Author(s):  
Jun Ru Li ◽  
Chen Gong ◽  
Le Yu Zhou ◽  
Lie Chen ◽  
Hui Zuo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Strength Properties ◽  
Quenching Temperature ◽  
Tempering Temperature ◽  
The Impact ◽  
Quenching And Tempering ◽  
Blade Steel ◽  
Tempering Process

In this work, the effects of final heat treatment including quenching and tempering process on mechanical properties of 10Cr12Ni3Mo2VN steel were investigated by orthogonal experimental. It is shown that, the quenching process had a small effect on the strength properties. But the impact property obviously decreased with the increase of quenching temperature, that is due to the grain coarsening. It can be found that tempering temperature is the major factor which affects the mechanical properties. Tempering process had a large effect on the precipitation of carbides and that affected the strength, toughness and plastic greatly. The impact toughness had a minimum after tempered at 650°C between 600°C~700°C. The experimental results show that the M23C6 type carbides precipitated at the grain and martensite lath boundary were the main reason which decreased the impact toughness when tempering temperature increased from 600°C to 650°C.

Deformation, Mechanical Properties, and Fracture of Quenched and Tempered Carbon Steels

2015 ◽  
pp. 405-437
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Ductile Fracture ◽  
Carbon Steels ◽  
Low Carbon ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Low Carbon Steels ◽  
Deformation Properties ◽  
Medium Carbon Steels

Abstract Steels with martensitic and tempered martensitic microstructures, though sometimes perceived as brittle, exhibit plasticity and ductile fracture behavior under certain conditions. This chapter describes the alloying and tempering conditions that produce a ductile form of martensite in low-carbon steels. It also discusses the effect of tempering temperature on the mechanical behavior and deformation properties of medium-carbon steels.

Microstructure and Mechanical Properties of High Strength Alloyed Steel for Aerospace Application

2018 ◽  
Vol 284 ◽  
pp. 351-356 ◽  
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim A. Ryzhkov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Strength ◽  
Single Stage ◽  
The Novel ◽  
Tempering Temperature ◽  
Quenching And Partitioning ◽  
Aerospace Application ◽  
Cooling Conditions ◽  
Quenching And Tempering

The high strength aerospace steel alloyed with Cr, Mn, Si, Ni, W and Mo was studied. The austenite transformations under continuous cooling conditions were investigated using the dilatometer analysis at the cooling rates 0.1...30 °C/s. The mechanical properties of the studied steel were determined after the conventional quenching and tempering heat treatment. The dependences of the mechanical properties on the tempering temperature were obtained. The novel quenching and partitioning heat treatment was applied to the steel under consideration. The microstructure and the mechanical properties were studied after three different modes of the quenching and partitioning (QP) treatment: single-stage QP, two-stage QP and single-stage QP with subsequent tempering (QPT).

scholarly journals Influence of Martensite Deformation on Cu Precipitation Strengthening

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 282
Author(s):  
Jaromir Dlouhy ◽  
Pavel Podany ◽  
Ján Džugan
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Cold Rolling ◽  
Temperature Dependence ◽  
Precipitation Hardening ◽  
Precipitation Strengthening ◽  
Tempering Temperature ◽  
Quenching And Tempering

Cu precipitation strengthening was compared in steels after treatments with and without cold rolling. A 0.2% C steel containing up to 1.5% Cu was quenched and tempered. Cu precipitation took place during tempering and increased its yield strength (YS). Quenched and tempered samples were compared with samples where cold rolling was performed between quenching and tempering. They exhibited significantly different mechanical properties. In addition, Cu alloying influenced the properties of each group of samples in different ways. The quenched and tempered samples exhibited behavior that is typical of precipitation hardening. Cu caused yield strength to increase with tempering temperature and time. The cold rolling of martensite reduced the maximal Cu-related strengthening and also eliminated its time and temperature dependence.

Significant Improvement in Strength and Toughness of Nanoscale Precipitate–Strengthened Steel by Direct Quenching and Tempering Process

2020 ◽  
pp. 2000331
Author(s):  
Jun Hu ◽  
Kang-Kang Liu ◽  
Li Ma ◽  
R. Devesh Kumar Misra ◽  
Wei-Na Zhang ◽  
...  
Keyword(s):  
Direct Quenching ◽  
Quenching And Tempering ◽  
Tempering Process ◽  
Strength And Toughness
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