Effect of Tempering on Hardness of Q&T Steel Plate

2018 ◽  
Vol 941 ◽  
pp. 311-316
Author(s):  
Aimee Goodall ◽  
Yu Lin Ju ◽  
Claire Davis ◽  
Martin Strangwood
Keyword(s):  
Heat Treatment ◽  
Single Phase ◽  
High Strength ◽  
Lower Bainite ◽  
Steel Plates ◽  
Isothermal Heat Treatment ◽  
Bainitic Structure ◽  
The Difference ◽  
Different Response ◽  
Quenching And Tempering

Commercial production of high strength steel plates by the quenching and tempering (Q&T) route requires control of alloy design and heat treatment parameters to achieve the desired strength and toughness through thickness. Plates with different thicknesses (up to approximately 100 mm) are produced for applications in the energy and power or lifting and excavation sectors. For thick plate the difference in cooling rate through thickness affects the as-quenched microstructure with martensite, auto-tempered martensite and lower and/or upper bainite being present. The different as-quenched microstructures can show a different response to tempering which affects the final strength and toughness.In this study the starting microstructure of a low alloy 0.17 wt% C Q&T steel has been varied using isothermal heat treatment at 430 °C to create mixed martensite and lower bainite microstructures (nominally 25:75; 50:50 and 75:25 percentages). The effects of tempering at 600 °C for times between 0.5 and 16 hours on the carbide precipitates and hardness of the mixed microstructures have been investigated and compared to the tempering response of single phase (martensite and lower bainite) microstructures. It has been found that the hardness decrease due to tempering is larger in the martensitic structure than the bainitic structure due to more rapid carbide coarsening. The as-quenched hardness of the mixed microstructures can be predicted by a rule of mixtures using the single phase properties. The tempering response of the mixed microstructures is discussed.

Mechanical Properties of a Mild-Alloy Steel for Aerospace Engineering

2021 ◽  
Vol 410 ◽  
pp. 221-226
Author(s):  
Mikhail V. Maisuradze ◽  
Maxim A. Ryzhkov ◽  
Dmitriy I. Lebedev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Strength ◽  
Aerospace Engineering ◽  
Isothermal Heat Treatment ◽  
Tempering Temperature ◽  
Optimal Heat Treatment ◽  
Treatment Conditions ◽  
Quenching And Tempering ◽  
Conventional Oil

The features of microstructure and mechanical properties of the aerospace high strength steel were studied after the implementation of various heat treatment modes: conventional oil quenching and tempering, quenching-partitioning, austempering. The dependence of the mechanical properties on the tempering temperature was determined. The basic patterns of the formation of mechanical properties during the implementation of isothermal heat treatment were considered. The optimal heat treatment conditions for the studied steel were established.

scholarly journals Evaluation of Microstructure and Selected Mechanical Properties of Laser Beam Welded S690QL High-Strength Steel

2018 ◽  
Vol 18 (3) ◽  
pp. 34-42 ◽  
Author(s):  
L. Tuz
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
High Strength Steel ◽  
High Strength ◽  
Fine Grain ◽  
Steel Material ◽  
Bainitic Structure ◽  
Haz Width ◽  
Quenching And Tempering ◽  
Softened Zone

AbstractThe paper presents results of microstructure and mechanical properties investigation of laser beam welded high-strength steel. Material for test was non-alloyed steel with yield strength of 690 MPa after quenching and tempering in delivery condition. Research carried out on the butt-welded joints shows fine-grain martensitic-bainitic structure of base metal and in the weld. Investigations of mechanical properties revealed the softened zone in HAZ where the hardness decrease without microstructural changes was observed. Moreover, an influence of softened zone and HAZ width on impact strength was observed where the occurrence of lower hardness led to fracture path deviation phenomenon.

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).

Effect of Different Heat Treatments on Microstructure and Mechanical Properties of the Martensitic Gx12CrMoVNbN9-1 Cast Steel / Wpływ Parametrów Obróbki Cieplnej Na Mikrostrukture I Własciwosci Mechaniczne Martenzytycznego Staliwa Gx12CrMoVNbn9-1

2013 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
G. Golanski ◽  
J. Słania
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Lath Martensite ◽  
High Strength ◽  
Strength Properties ◽  
Microstructure And Mechanical Properties ◽  
Quenching And Tempering ◽  
Very High

The paper presents a research on the influence of multistage heat treatment with the assumed parameters of temperature and time on the microstructure and mechanical properties of high-chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. In the as-cast state GP91 cast steel was characterized by a microstructure of lath martensite with numerous precipitations of carbides of the M23C6, M3C and NbC type, with its properties higher than the required minimum. Hardening of the examined cast steel contributes to obtaining a microstructure of partly auto-tempered martensite of very high strength properties and impact strength KV on the level of 9-15 J. Quenching and tempering with subsequent stress relief annealing of GP91 cast steel contributed to obtaining the microstructure of high-tempered lath martensite with numerous precipitations of the M23C6 and MX type of diverse size. The microstructure of GP91 cast steel received after heat treatment was characterized by strength properties (yield strength, tensile strength) higher than the required minimum and a very high impact energy KV. It has been proved that GP91 cast steel subject to heat treatment No. 2 as a result of two-time heating above the Ac3 temperature is characterized by the highest impact energy.

Effect of Isothermal Heat Treatment on Dynamic Properties of a High Strength Steel

2015 ◽  
Vol 782 ◽  
pp. 124-129
Author(s):  
Wen Wen Du ◽  
Qian Wang ◽  
Lin Wang ◽  
Ding Wang
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
Strain Rate ◽  
High Strength Steel ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
High Strength ◽  
Isothermal Heat Treatment ◽  
Quenching Temperature ◽  
Isothermal Temperature

The high strength steel which was subjected with isothermal heat treatment at three different temperatures, namely 330°C, 350°Cand 380°C after different quenching temperature namely 880°C and 900°C,was investigated in this paper. The quasi-static and dynamic mechanical properties of new high strength steel was tested by universal material testing machine and Split Hopkinson Pressure Bar (SHPB). Experimental results have showed that the yield strength and tensile strength of the steel reach 1100MPa and 1400MPa respectively. Hardness, yield strength and toughness are found to decrease with the consequently increasing of isothermal temperature under the same quenching temperature. The compression properties of the steel under quenching temperature of 880°C are higher than that of 900°C with the same isothermal temperature. It can be found that the steel which is subjected with isothermal heat treatment show strain rate sensitivity under high velocity impact. When isothermal temperature is set 380°C, the steel exhibits the most obvious strain rate hardening effect.

Development of 550 MPa Yield Strength Steel Plate for Offshore Structures

2004 ◽  
Author(s):  
Takahiro Kamo ◽  
Takeshi Urabe ◽  
Kazushi Ohnishi ◽  
Hirofumi Nakamura ◽  
Shuji Okaguchi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
Base Metal ◽  
Steel Plate ◽  
High Strength ◽  
Offshore Structures ◽  
Steel Plates ◽  
Offshore Structure ◽  
Copper Precipitation ◽  
High Toughness

Offshore structure steel with high strength of YS550MPa has been investigated. As for offshore structure steel, high toughness in welded joints is required in addition to that in base metal. TMCP type steel of up to YS420MPa grade is used widely, and up to YS500MPa grade is reported in some papers. However, steel of higher strength grade with good toughness and weldability will be beneficial to structures in strict conditions. To reach the YS550MPa requirement, hardening effect by Cu precipitation was utilized. Steel plates were designed with micro-alloyed low C-Mn-Cu-Ni-Cr-Mo system. The combination of the copper precipitation and TMCP technology can increase strength without deteriorating toughness and weldability. Heat treatment for Cu precipitation was carried out to optimize the balance of strength and toughness of the base metal. The developed steel also shows good HAZ CTOD toughness up to 76.2mm thickness in several welding conditions including after PWHT. The newly developed steel has the possibility to increase the flexibility to design large-sized structures.

Phase Transformations in D6AC Steel during Continuous Cooling

2017 ◽  
Vol 265 ◽  
pp. 712-716 ◽  
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim Ryzhkov ◽  
Aleksandra A. Kuklina
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Transformations ◽  
High Strength ◽  
Treatment Technology ◽  
Heat Treatment Technology ◽  
Cooling Conditions ◽  
Drill Bits ◽  
Steel Drill ◽  
Quenching And Tempering

The CCT diagram of the high strength D6AC steel was plotted using the dilatometer data, microstructure investigation, and hardness measurements. The microstructure of the steel under consideration was estimated after various cooling conditions and quenching and tempering. The heat treatment technology of D6AC steel drill bits was developed to obtain the required mechanical properties.

scholarly journals EFFECTS OF Q&P PROCESS PARAMETERS ON PROPERTIES OF 42SiCr STEEL

2018 ◽  
Vol 24 (2) ◽  
pp. 126
Author(s):  
Kateřina Rubešová ◽  
Ivan Vorel ◽  
Hana Jirková ◽  
Štěpán Jeníček
Keyword(s):  
Heat Treatment ◽  
Ultimate Strength ◽  
Retained Austenite ◽  
High Strength ◽  
Carbon Diffusion ◽  
Salt Bath ◽  
Treatment Techniques ◽  
Microstructure Effects ◽  
The Impact ◽  
Quenching And Tempering

<p class="AMSmaintext"><span lang="EN-GB">The requirement for high strength and good ductility poses problems in today’s advanced steels. This problem can be tackled by appropriate heat treatment which produces suitable microstructures. By this means, ultimate strengths of about 2000 MPa and elongations of more than 10% can be obtained. One of such advanced heat treatment techniques is the Q&amp;P (Quenching and Partitioning) process. It produces a mixture of martensite and retained austenite, where the latter is an important agent in raising the ductility of steel. </span></p><p class="AMSmaintext"><span lang="EN-GB">In this experiment, a low-alloy steel with 0.41% carbon and manganese, silicon and chromium was used. An air furnace and a salt bath were employed for heat treatment and quenching, respectively. In order to obtain the best ultimate strength and elongation levels, partitioning temperatures of 250°C and 300°C were applied. Partitioning involves carbon diffusion from super-saturated martensite into retained austenite, and tempering of hardening microstructure. Effects of the quenching temperatures of 200°C and 150°C were studied as well. To map the impact of the Q&amp;P process on mechanical properties, an additional schedule with conventional quenching and tempering was carried out. Upon optimization of the parameters, the process produced martensite with a small amount of bainite and retained austenite. The ultimate strength was between 1930 and 2080 MPa and the elongation levels were from 9 to 16%.</span></p><p class="AMSmaintext"><span lang="EN-GB"> </span></p>

scholarly journals Quenching and tempering parameter on Indonesian hot rolled plate steel for armour steel

2018 ◽  
Vol 204 ◽  
pp. 05001 ◽  
Author(s):  
Yurianto ◽  
Pratikto ◽  
Rudy Sonoko ◽  
Wahyono ◽  
A.P. Bayuseno
Keyword(s):  
Heat Treatment ◽  
Impact Energy ◽  
High Strength ◽  
Rolled Plate ◽  
Plate Steel ◽  
Direct Pressure ◽  
Hot Rolled ◽  
Temper Heat Treatment ◽  
Armour Steel ◽  
Quenching And Tempering

Armour steel is a high strength and hardness steel used to protect damage by an object, individual or vehicle from the direct pressure of projectile. This steel used for military and commercials equipment in Indonesia and produced out of hot rolled plate steel made by PT. Krakatau Steel (Persero) Cilegon, Banten, Indonesia. By using quench (with water sprayed) and temper heat treatment produced Quenched & Tempered Steels. The aim of the study to obtain optimum quenching and tempering parameter in hardness and impact energy of HRP Steel. Method of this study by optimizing austenite temperature; austenite holding time; temper temperatures; hardness and impact energy. The result of this study is austenite temperatures 900°C (held 45 minutes) and temper temperatures 125°C (held 45 minutes). Prediction of both hardness and impact energy is 569.96 HVN (536.00 BHN) and 30.50 J respectively.

Microstructure and Mechanical Properties of the Heat Treated Hy-TUF Steel

2020 ◽  
Vol 989 ◽  
pp. 324-328
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim A. Ryzhkov
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
High Strength ◽  
Lower Bainite ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated ◽  
Upper Bainite ◽  
Quenching And Tempering ◽  
Conventional Oil

A study of the high-strength HY-TUF steel applied for the manufacturing of heavy loaded parts was carried out. The mechanical properties of the austempered HY-TUF steel were compared to the characteristics obtained after the conventional oil quenching and tempering. The upper bainite with low impact strength was formed during the austempering at 400 °C and higher. Conventional oil quenching and tempering at temperature 400...500 °С also led to the embrittlement of the steel under consideration. The best combination of toughness and strength of the HY-TUF steel was achieved after the austempering at the temperature of lower bainite formation.

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