scholarly journals Overview Impacts of Heat Treatment Techniques on Grain Structures of a Steel

2021 ◽  
Vol 1107 (1) ◽  
pp. 012137
Author(s):  
S. A. Afolalu ◽  
E.Y. Salawu ◽  
O. O. Joseph ◽  
S. Oladipupo ◽  
M. E. Emetere ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Techniques ◽  
Grain Structures

The Use of Optimized ERW Technique to Improve Low Temperature Fracture Toughness of Welded Pipes

2020 ◽  
Author(s):  
Muhammad Rashid ◽  
Timothy Hylton ◽  
Neil Anderson ◽  
Laurie Collins ◽  
Leijun Li
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Low Temperature ◽  
Weld Seam ◽  
Peak Temperature ◽  
Line Pipe ◽  
Squeeze Pressure ◽  
Treatment Practices ◽  
Treatment Techniques ◽  
Research Activities

Abstract It is understood that the bondline microstructure of the line pipe ERW seam can be a zone of weakness in the pipe. To overcome this weakness, several research projects utilizing various line pipe steel grades and welding and heat treatment techniques have been conducted at EVRAZ NA. The overall goal of these efforts has been to understand the development of bondline microstructure during the ERW process and improve the weld seam fracture toughness for low temperature applications. These research activities included mill trials and Gleeble simulations. It was realized that a high toughness ERW weld seam is only possible through a tightly controlled combination of weld power, forging (squeeze) pressure, and welding speed. Research studies have indicated that the as-welded seam may not pass the standard ERW destructive tests if proper heat input and adequate squeeze pressure are not applied. Post weld heat treatment (normalizing) practice was also found to be a key element in the development of the appropriate bondline microstructure for higher toughness. Samples from pipes normalized using different heat treatment practices produced different bondline microstructures and hence different toughness properties. It was found through this study that a low (but still higher than the upper critical temperature Ac3) normalizing peak temperature and adequate soak time at the peak temperature result in improved Charpy toughness of ERW bondline microstructure.

Effect of Heat Treatment Technique on the Low Temperature Impact Toughness of Steel EQ70 for Offshore Structure

2017 ◽  
Vol 36 (8) ◽  
pp. 825-830 ◽  
Author(s):  
Su-Fen Tao ◽  
Yun-Jin Xia ◽  
Fu-Ming Wang ◽  
Jie Li ◽  
Ding-Dong Fan
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Impact Toughness ◽  
Treatment Technique ◽  
Offshore Structure ◽  
Treatment Techniques ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness ◽  
The Impact ◽  
Quenching And Tempering

AbstractCircle quenching and tempering (CQ&T), intercritical quenching and tempering (IQ&T) and regular quenching and tempering (Q&T) were used to study the influence of heat treatment techniques on the low temperature impact toughness of steel EQ70 for offshore structure. The steels with 2.10 wt. % Ni (steel A) and 1.47 wt. % Ni (steel B) were chosen to analyze the effect of Ni content on the low temperature impact toughness of steel EQ70 for offshore structure. The fracture morphologies were examined by using a scanning electron microscope (SEM, JSM-6480LV), and microstructures etched by 4 vol. % nitric acid were observed on a type 9XB-PC optical microscope. The results show that the impact toughness of steel A is higher than that of steel B at the same test temperature and heat treatment technique. For steel B, the energy absorbed is, in descending order, CQ&T, Q&T and IQ&T, while for steel A, that is CQ&T, IQ&T and Q&T. The effects of heat treatment on the low temperature impact toughness are different for steels A and B, the absorbed energy changes more obviously for steel A. The results can be significant references for actual heat treatment techniques in steel plant.

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>

Effect of isothermal compression and subsequent heat treatment on grain structures evolution of Al-Mg-Si alloy

2021 ◽  
Vol 28 (9) ◽  
pp. 2670-2686
Author(s):  
Ze-cheng Li ◽  
Yun-lai Deng ◽  
Man-fa Yuan ◽  
Jin Zhang ◽  
Xiao-bin Guo
Keyword(s):  
Heat Treatment ◽  
Subsequent Heat Treatment ◽  
Isothermal Compression ◽  
Grain Structures
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