scholarly journals INFLUENCE OF HEAT TREATMENTS ON THE MICROSTRUCTURE OF WELDED API X70 PIPELINE STEEL

2017 ◽  
Vol 23 (1) ◽  
pp. 72 ◽  
Author(s):  
Keltoum Digheche ◽  
Zakaria Boumerzoug ◽  
Malika Diafi ◽  
Khawla Saadi
Keyword(s):  
Heat Treatment ◽  
Pipeline Steel ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Heat Treatments ◽  
Isothermal Heat Treatment ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Welded Pipe

<p class="AMSmaintext"><span lang="EN-GB">Welding is one of the most important technological processes used in many branches of industry such us industrial engineering, shipbuilding, pipeline fabrication among others. Generally, welding is the preferred joining method and most common steel are weldable. This investigation is a contribution to some scientific works which have been done on welding of low carbon steel. This work, presents some heat treatments were used to alter the microstructure of base metal (BM), heat affected zone (HAZ) and weld metal (WM) in the welded pipe steel of grade API X70. It presents the microstructures obtained after three heat treatments at 200°C, 400°C and 600°C for 30 min. Scanning electron microscopy and X-ray diffraction have been used as characterization techniques to observe the WM microstructures, in addition the Vickers hardness test are also achieved. The results revealed that the isothermal heat treatment caused grain growth and coarsening reactions in the weld zone and the hardness of weld joints decreased were the main transformations after increasing the temperature of the heat treatment. </span></p>

Applying of Heat Treatments to Improve the Properties of Welded Pipeline Steel

2019 ◽  
Vol 297 ◽  
pp. 143-150
Author(s):  
Kaltoum Digheche ◽  
Zakaria Boumerzoug ◽  
Farida Khamouli ◽  
Adel Saoudi ◽  
Khawla Saadi
Keyword(s):  
Heat Treatment ◽  
Arc Welding ◽  
Pipeline Steel ◽  
Weld Zone ◽  
Heat Treatments ◽  
Isothermal Heat Treatment ◽  
X Ray Diffraction ◽  
Shielded Metal Arc Welding ◽  
X Ray ◽  
Metal Arc Welding

This work, presents some heat treatments were used to improve the microstructure in different zones of the API X70 welded pipeline steel. In this study a shielded metal arc welding (SMAW) process has been realized.. Scanning electron microscopy and X-ray diffraction have been used as characterization techniques to observe the WM microstructures, in addition hardness are also measured. The results revealed that the isothermal heat treatment caused progressive recristallization reactions in the weld zone, and the hardness of weld joints decreased, were the main transformations after increasing the temperature of the heat treatment.

Correlation between microstructural evolution during high-pressure torsion and isothermal heat treatment of amorphous Al85Gd8Ni5Co2 alloy

2010 ◽  
Vol 25 (7) ◽  
pp. 1388-1397 ◽  
Author(s):  
Péter Henits ◽  
Ádám Révész ◽  
Erhard Schafler ◽  
Péter J. Szabó ◽  
János L. Lábár ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Thermal Sensitivity ◽  
Heat Treatments ◽  
Isothermal Heat Treatment ◽  
X Ray Diffraction ◽  
Continuous Heat Treatment ◽  
Isothermal Heat Treatments ◽  
Continuous Heat

Al85Gd8Ni5Co2 metallic glass was subjected to partial devitrification by high-pressure torsion, continuous heat treatment, and isothermal annealing. The fully amorphous alloy exhibits a well-defined transition in its first devitrification product during isothermal heat treatments from τm + α-Al phase mixture to primary α-Al by increasing the annealing temperature above 555 K. This thermal sensitivity predestinates the composition to identify the controversial thermal contribution of the plastic deformation in metallic glasses. Thermal stability and structure of the partially devitrified samples were systematically analyzed and compared by calorimetry, x-ray diffraction, and electron microscopy. It seems that the effect of severe deformation cannot be singled out by a simple isothermal heat treatment; i.e., high-pressure torsion acts as a spectrum of heat treatments performed at different annealing temperatures.

Effect of Heat Treatments on Microstructure and Mechanical Properties of Low Carbon Steel Pipes Welded by Induction Process

2014 ◽  
Vol 887-888 ◽  
pp. 1301-1306
Author(s):  
Zakaria Boumerzoug ◽  
Lakhdar Lakhdari
Keyword(s):  
Mechanical Properties ◽  
Isothermal Annealing ◽  
Pipeline Steel ◽  
Low Carbon Steel ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Low Carbon ◽  
Steel Pipes ◽  
Induction Process ◽  
Isothermal Heat Treatments

In this work, the effect of isothermal heat treatments on microstructure evolution and mechanical properties after welding by induction of A37 pipeline steel have been studied by scanning electron microscopy, hardness measurements, and tensile tests. Microstructural evolution in welded joint was identified after isothermal annealing from 200 until 900 °C.

scholarly journals Influence of Annealing on Strength of Ultrafine Grained Low Carbon Steels by ECAP

2010 ◽  
Vol 638-642 ◽  
pp. 1899-1904 ◽  
Author(s):  
T. Akita ◽  
Masahide Gotoh ◽  
Sergey V. Dobatkin ◽  
Kazuo Kitagawa ◽  
Yukio Hirose
Keyword(s):  
Low Carbon Steel ◽  
Hardness Test ◽  
Carbon Steels ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermal Reactions ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ultrafine Grained

In the present study, ultra fine-grained low carbon steel samples were processed by equal channel angular pressing (ECAP). Mechanical properties of the specimens annealed statically at several temperatures were evaluated by tensile and hardness test. In addition, grain sizes of the specimens were measured by SEM-electron back scattering pattern (SEM-EBSP) and X-ray diffraction analysis. Differential scanning calorimetry (DSC) measurement also evaluated thermal reactions in anneal process of the specimen. As a result, the grain size was changed at the temperature between 550oC and 600oC drastically and the tensile strength also became lower at the same temperature. The relation between yield stress and averaged grain diameter of specimens obeyed the Hall-Petch relation except the normalized specimen. Behavior of grain growth and recovery in structural observation by EBSP corresponded to reaction signal of the DSC curve.

PENGARUH ARUS TERHADAP STRUKTUR MIKRO DAN KEKERASAN LASAN JIS Z 3251 DF2A-350-R

2019 ◽  
Vol 4 (1) ◽  
pp. 21-25
Author(s):  
Basori Basori ◽  
Syamsuir Syamsuir
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Low Carbon ◽  
Steel Material ◽  
Heat Treated

AbstrakDilakukan pengelasan dengan elektroda JIS Z 3251 DF2A-350-R dengan tiga variasi arus yaitu 120, 140 dan 160A. Pengelasan dilakukan satu lapis pada material baja karbon rendah. Setelah selesai pengelasan, spesimen langsung dicelupkan ke dalam air. Setelah mendingin kemudian spesimen dilakukan heat treatment dengan temperatur 1000 oC selama 10 menit kemudian dicelup dalam media coolant. Kemudian dilakukan uji kekerasan dan foto mikro. Hasil menunjukkan semakin tinggi arus maka akan semakin tinggi nilai kekerasan baik spesimen yang dicelup coolant maupun tidak. Kata kunci: SMAW, JIS Z 3251 DF2A-350-R, Coolant, Struktur Mikro dan Kekerasan AbstractWelding is done with JIS Z 3251 DF2A-350-R electrodes with three current variations 120, 140 and 160A. Welding is carried out in one layer on low carbon steel material. After welding, the specimen is immediately dipped in water. After cooling, then the specimens were heat treated with the temperature 1000 oC for 10 minutes then dipped in the coolant media. Then the hardness test and microstructure were carried out. The results show that the higher the current, the higher the hardness value whether or not the coolant is dyed. Keywords: SMAW, JIS Z 3251 DF2A-350-R, Coolant, Microstructure and Hardness

scholarly journals THERMAL INFLUENCE ON THE MICROSTRUCTURE AND THE MICRO HARDNESS OF A CARBON STEEL WELD PROBES

2020 ◽  
Vol 5 (8) ◽  
pp. 1-10
Author(s):  
Mbelle Samuel Bisong ◽  
Kisito Pierre ◽  
Valeriy Lepov
Keyword(s):  
Carbon Steel ◽  
Heat Affected Zone ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Low Carbon ◽  
Micro Hardness ◽  
Structural Examination ◽  
Fine Grained ◽  
Thermal Influence

During welding, the heat produced during the process can affect the microhardness and the microstructure of the material. The change in the microstructure and the microhardness can be discovered by carrying out a microhardness test on the welded sample and compare changes in the three different zones i.e the base, the weld and the Heat affected zone or by carrying out a micro structural examination on the welded sample and see the grain dispersion in relation to their sizes. In this work, weld quality of manual arc welded samples of low-carbon steel St3spdestined for bridge construction to be used in Cameroon has been investigated. After a chemical analysis of the material, a micro hardness test and a micro structural examination was also done. Results show that a composition of pearlite and ferrite was seen with the print of the id enter of the micro hardness test. The formation of pearlite and ferrite in base metalis composed of 20/80 respectively. For weld zone and HAZ it changes due to thermal processes. So the microstructure analysis shows that the base metal is a ferrite and pearlite having a grain size of 11-12 on a scale corresponding to an average grain diameter ≈ 7 microns. The structure of the weld metal is also made up of ferrite and pearlite with columnar crystals of cast metal. The HAZ is made up of Widmanstätten. The width of the HAZ zone is about 1,5 mm. In different areas of heat affected zone is observed fine-grained ferrite-pearlite structure with a high degree of dispersion.

Isothermal Heat Treatment of the Low-Carbon Martensitic Steel

2021 ◽  
Vol 316 ◽  
pp. 264-268
Author(s):  
Mikhail V. Maisuradze ◽  
Aleksandra A. Kuklina ◽  
Dmitriy I. Lebedev
Keyword(s):  
Heat Treatment ◽  
Martensitic Steel ◽  
Low Carbon Steel ◽  
Residual Austenite ◽  
Isothermal Heat Treatment ◽  
Low Carbon ◽  
Tempered Martensite ◽  
High Hardenability ◽  
Carburized Steel ◽  
Carbon Martensitic Steel

A study of the low-carbon steel with high hardenability was carried out. The steel contained the following alloying elements, wt. %: C – 0.20; Cr – 2.0; Mn – 2.0; Si – 1.04 Ni – 1.0; Mo – 0.3. The quenching – partitioning treatment of the studied steel was implemented. The microstructure of the steel consisted of the tempered martensite laths, bainite and martensite-austenite regions. The amount of the residual austenite and the carbon concentration in the residual austenite were estimated. The possibility of the quenching – partitioning treatment of the carburized steel was shown.

scholarly journals ANALISA KEKERASAN DAN STRUKTUR MIKRO PADA BAJA AISI 1018 AKIBAT PROSES PACK CARBURIZING DENGAN VARIASI KONSENTRASI SERBUK CANGKANG KEONG EMAS

2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Achmad Zainuri ◽  
Paryanto Dwi Setyawan ◽  
Prayuda Atmam
Keyword(s):  
Heat Treatment ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Carbon Diffusion ◽  
Low Carbon ◽  
Steel Cylinder ◽  
Microstructure Observation ◽  
Material Hardness ◽  
Powder Addition ◽  
Shell Powder

This research to investigate the effect of Pomacea Canalikulata Lamarck powder addition in the process of carburization box to physical (microstructure) and mechanical properties (hardness test) of AISI 1018 after heat treatment. In this research used a material of low carbon steel cylinder (AISI 1018). The process of making the specimen is done with to cut into several pieces, cutting done to ease in placing the specimen in the carburizing box, then wood charcoal powder and shell powder were weighed in accordance with the desired composition by mixing powder of 5 wt%, 10 wt%, and 15 wt%. The specimen was done heat treatment at a temperature of 9500C with the holding time at 2, 4 and 6 hours. Then, the specimen was done the Vickers hardness test, microstructure and composition test. From this research it can be concluded that the highest hardness value was obtained at 15 wt% addition of shell powder it was 262.26 kg/mm2 and the initial material hardness value was 144.08 kg/mm2. From microstructure observation and composition test show that it subjected surface hardening because carbon diffusion into specimen.

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