Microstructure and Properties of X100 High Strength Pipeline Steel

2015 ◽  
Vol 814 ◽  
pp. 325-332 ◽  
Author(s):  
Yu Xiao Tian ◽  
Bin Wang ◽  
Jun Liang Li ◽  
Bo Li Chen ◽  
Quan Feng
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
Pipeline Steel ◽  
Testing Machine ◽  
Welding Process ◽  
Test Machine ◽  
Tensile Testing Machine ◽  
Microstructure And Properties ◽  
The Impact

In order to study the effect of welding process on the microstructure and properties of weld joint of X100 pipeline steel, GMAW was used to prepare the weld joint with low-carbon high manganese-molybdenum-nickel flux cored welding wire. SEM and XRD were used to analyze the microstructure and phase morphology of HAZ and weld metal. Hydraulic tensile testing machine and impact test machine were used to test the mechanical properties. The experimental results showed that the weld metal and HAZ were composed of bainite, ferrite and M/A, the microstructure was fine and uniform with columnar crystal morphology, and HAZ was quite coarse. Hardness of weld metal was 248HV, which is higher than that of base metal, however, HAZ was softening. The tensile strength of weld joint was 832Mpa, which is about 96% of the base metal. The impact absorbed energy at-20°C of the base metal and weld metal were 291J and 121J respectively, exhibiting excellent strength and toughness.

scholarly journals Effects of temperature and impactor nose diameter on the impact behavior of PA6 and PP thermoplastic composites

2018 ◽  
Vol 51 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Akar Dogan ◽  
Yusuf Arman
Keyword(s):  
Load Capacity ◽  
Testing Machine ◽  
Polyamide 6 ◽  
Impact Testing ◽  
Impact Behavior ◽  
Thermoplastic Composites ◽  
Test Machine ◽  
Effects Of Temperature ◽  
Impact Energies ◽  
The Impact

In this study, the effects of temperature and impactor nose diameter on the impact behavior of woven glass-reinforced polyamide 6 (PA6) and polypropylene (PP) thermoplastic composites were investigated experimentally. Impact energies are chosen as 10, 30, 50, 70, 90, 110, 130, and 170 J. The thickness of composite materials is 4 mm. Impact tests were performed using a drop weight impact testing machine, CEAST-Fractovis Plus, and the load capacity of test machine is 22 kN. Hemispherical impactor nose diameter of 12, 7, and 20 mm were used as an impactor. The tests are conducted at room temperature (20°C and 75°C). As a result, the PP composites of the same thickness absorbed more energy than PA6 composites. The amount of absorbed energy of PP and PA6 composites decreased with temperature.

scholarly journals Study the Effect of Welding Heat Input on the Microstructure, Hardness, and Impact Toughness of AISI 1015 Steel

2018 ◽  
Vol 14 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Emad Kh. Hamd ◽  
Abbas Sh. Alwan ◽  
Ihsan Khalaf Irthiea
Keyword(s):  
Corrosion Rate ◽  
Weld Joint ◽  
Heat Input ◽  
Plate Thickness ◽  
Welding Process ◽  
Welding Current ◽  
Low Carbon ◽  
Mig Welding ◽  
The Impact ◽  
Weld Heat

In the present study, MIG welding is carried out on low carbon steel type (AISI 1015) by using electrode ER308L of 1.5mm diameter with direct current straight polarity (DCSP). The joint geometry is of a single V-butt joint with one pass welding stroke for different plate thicknesses of 6, 8, and 10 mm. In welding experiments, AISI 1015 plates with dimensions of 200×100mm and edge angle of 60o from both sides are utilized. In this work, three main parameters related to MIG welding process are investigated, which are welding current, welding speed, heat input and plate thickness, and to achieve that three groups of plates are employed each one consists of three plates. The results indicate that increasing the weld heat input (through changing the current and voltage) leads to an increase in widmanstatten ferrite (WF), acicular ferrite (AF) and polygonal ferrite (PF) in FZ region, and a reduction in grain size. It is observed that the micro-hardness of welded AISI 1015 plate increases as the weld heat input decreases. As well as increasing the weld heat input results in an increase in the width of WM and HAZ and a reduction in the impact energy of the weld joint of AISI 1015 at WM region. Also, it is noted the corrosion rate of weld joint increases with increase of Icorr due to increasing in welding current (heat input), corrosion rate increased up to (0.126µm/yr.) with increasing of heat input up to (1.27 KJ/mm).  

A model study on the impact of metal ions on pre-vulcanization of concentrated natural rubber latex and dipped-products

2021 ◽  
pp. 147776062110629
Author(s):  
Porntip Rojruthai ◽  
Narueporn Payungwong ◽  
Jitladda T Sakdapipanich
Keyword(s):  
Natural Rubber ◽  
Metal Ions ◽  
Colloidal Stability ◽  
Mechanical Stability ◽  
Testing Machine ◽  
Natural Rubber Latex ◽  
Tensile Testing Machine ◽  
Model Study ◽  
Stability Time ◽  
The Impact

A model study on the influence of some heavy metal ions on the stability and vulcanization efficiency of uncompounded and compounded high-ammonia natural rubber (HANR) latex was carried out by an exogenous addition and then determined by Brookfield viscometer, mechanical stability time (MST) tester, and tensile testing machine. The case of pre-vulcanized HANR latex with different aging times was determined by the change in the volatile fatty acid (VFA) number, MST, and viscosity. The compounded HANR latex was coagulated by adding Mn2+and Mg2+ while it was unaltered by adding Zn2+, Fe2+, and Cu2+ ions, leading to their colloidal stability. Therefore, these metal ions were chosen further to study the pre-vulcanization of compounded HANR latex. The presence of Zn2+, Fe2+, and Cu2+ in the latex is responsible for the delay in the vulcanization process and changes the appearance of compounded latex. Before compounding, the addition of such metal ions led to the reduction in tensile strength of the obtained gloves. At the same time, there was no effect on the tensile properties of the gloves made from the compounded HANR latex containing the metal ions.

scholarly journals A Combination of Keyhole GTAW with a Trapezoidal Interlayer: A New Insight into Armour Steel Welding

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3571 ◽  
Author(s):  
Zhenyu Fei ◽  
Zengxi Pan ◽  
Dominic Cuiuri ◽  
Huijun Li ◽  
Azdiar A. Gazder
Keyword(s):  
Chemical Composition ◽  
Weld Metal ◽  
Base Metal ◽  
Welding Process ◽  
Charpy Impact ◽  
Filler Materials ◽  
Temperature Phase ◽  
Ballistic Performance ◽  
Two Phase ◽  
Armour Steel

The ballistic performance of armour steel welds using austenitic filler materials is poor on account of the disparity in the mechanical properties of the weld and base metals. Consequently, a novel Keyhole Gas Tungsten Arc Welding process with a trapezoidal AISI309 austenitic stainless steel interlayer was developed to tailor chemical composition and microstructure by controlling the solidification sequence. Results show that the dilution rate in the weld metal region can reach up to 43.5% by placing a specially designed interlayer in between the base metal, providing a major scope for microstructure modification. Detailed weld analysis was undertaken by X-ray diffraction, optical and secondary and transmission electron microscopy, energy dispersive spectroscopy and electron back-scattering diffraction. The results from Vickers hardness indents and Charpy impact toughness testing at −40 °C show that the properties of the weld metal region are comparable to that of the base metal. This is ascribed to the weld metal comprising a two phase microstructure of martensite and retained austenite, which contribute to improvements in strength and toughness, respectively. Furthermore, the tailored chemical composition, microstructure and low temperature phase transformation in the weld metal may reduce the tendency toward both solidification cracking and hydrogen assisted cold cracking.

Application of FIB/SEM/EBSD for Evaluation of Residual Strains and Their Relationship to Weld Metal Hydrogen Assisted Cold Cracking

2012 ◽  
Author(s):  
W. L. Costin ◽  
I. H. Brown ◽  
L. Green ◽  
R. Ghomashchi
Keyword(s):  
Residual Stresses ◽  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Ion Beam ◽  
Base Material ◽  
Welding Process ◽  
Cold Cracking ◽  
Predictive Methods ◽  
Residual Strains

Hydrogen assisted cold cracking (HACC) is a welding defect which may occur in the heat affected zone (HAZ) of the base metal or in the weld metal (WM). Initially the appearance of HACC was associated more closely with the HAZ of the base metal. However, recent developments in advanced steel processing have considerably improved the base material quality, thereby causing a shift of HACC to the WM itself. This represents a very serious problem for industry, because most of the predictive methods are intended for prevention of HACC in the HAZ of the base metal, not in the weld metal [1]. HACC in welded components is affected by three main interrelated factors, i.e. a microstructure, hydrogen concentration and stress level [2–4]. In general, residual stresses resulting from the welding process are unavoidable and their presence significantly influences the susceptibility of weld microstructures to cracking, particularly if hydrogen is introduced during welding [5]. Therefore various weldability tests have been developed over the years which are specifically designed to promote HACC by generating critical stress levels in the weld metal region due to special restraint conditions [4, 6–8]. These tests were used to develop predictive methods based on empirical criteria in order to estimate the cracking susceptibility of both the heat-affected zone and weld metal [4]. However, although the relationship between residual stress, hydrogen and HACC has received considerable attention, the interaction of residual stresses and microstructure in particular at microscopic scales is still not well understood [5, 9–21]. Therefore the current paper focuses on the development and assessment of techniques using Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction for the determination of local residual strains at (sub) micron scales in E8010 weld metal, used for the root pass of X70 pipeline girth welds, and their relationship to the WM microstructure. The measurement of these strains could be used to evaluate the pre-existing stress magnitudes at certain microstructural features [22].

Effects of Filler Compositions on Mechanical and Physical Properties of the Dissimilar Resistance Spot Welded between Aluminium Alloy and Carbon Steel

2015 ◽  
Vol 656-657 ◽  
pp. 422-427
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Muhammad Fathan
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Physical Properties ◽  
Aluminium Alloy ◽  
Base Metal ◽  
Testing Machine ◽  
Optical Microscope ◽  
Filler Materials ◽  
Al Alloy ◽  
Resistance Spot

The resistance spot weld (RSW) of dissimilar materials betweeen steel and aluminium is generally more complex than that of similar materials due to the extreme differences in the mechanical, physical and chemical properties of the base metals. This study proposed the use of filler material to connect the differences of their properties. Al-Alloy 5083 with thickness of 4 mm and 1.2 mm thick carbon steel SS400 were joined in lap joint types using RSW with the filler materials. The filler materials were a mixture of steel and aluminium in which weight composition variations (Fe:Al) were 90:10; 70:30; 30:70 and 90:10 in percent. The physical properties were examined based on the microstructure using optical microscope while the mechanical properties were measured with respect to the strength and hardness using Universal Testing Machine and Vickers Microhardness respectively. Results showed that weld metals with filler composition of 70:30% had highest shear-strength. The microstructure examinations showed that Microstructure of base metal and HAZ carbon steel was ferrite and perlite while that of weld metal was bainite. There were no significant differences in the microstructures and the hardness of weld metal, HAZ, and the base metal of aluminium alloy-5083 due to nonheat-treatable material.

scholarly journals Effect of Microstructure on Hydrogen Diffusion in Weld and API X52 Pipeline Steel Base Metals under Cathodic Protection

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
R. C. Souza ◽  
L. R. Pereira ◽  
L. M. Starling ◽  
J. N. Pereira ◽  
T. A. Simões ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Cathodic Protection ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Pipeline Steel ◽  
Sodium Thiosulfate ◽  
Hydrogen Flow ◽  
Electrochemical Tests

The aim of this research was to evaluate the influence of microstructure on hydrogen permeation of weld and API X52 base metal under cathodic protection. The microstructures analyzed were of the API X52, as received, quenched, and annealed, and the welded zone. The test was performed in base metal (BM), quenched base metal (QBM), annealed base metal (ABM), and weld metal (WM). Hydrogen permeation flows were evaluated using electrochemical tests in a Devanathan cell. The potentiodynamic polarization curves were carried out to evaluate the corrosion resistance of each microstructure. All tests were carried out in synthetic soil solutions NS4 and NS4 + sodium thiosulfate at 25°C. The sodium thiosulfate was used to simulate sulfate reduction bacteria (SRB). Through polarization, assays established that the microstructure does not influence the corrosion resistance. The permeation tests showed that weld metal had lower hydrogen flow than base metal as received, quenched, and annealed.

Creep Properties of Nitrogen-Alloyed Type 316L Stainless Steel

2007 ◽  
Author(s):  
M. D. Mathew ◽  
C. Girish Shastry ◽  
S. Latha ◽  
K. Bhanu Sankara Rao
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
316L Stainless Steel ◽  
Rupture Strength ◽  
Creep Rupture Strength ◽  
Creep Properties ◽  
Type 316L ◽  
Type 316L Stainless Steel

Type 316L stainless steel (SS) alloyed with 0.06–0.08 wt% nitrogen is the principal structural material for the sodium circuit components of India’s Prototype Fast Breeder Reactor. Carbon in the range of 0.045–0.055 wt% and nitrogen in the range of 0.06–0.10 wt% have been specified for the welding consumable to provide weld joints with creep strength as close as possible to that of the base metal. Design of the components is based on RCC-MR fast reactor code. Creep properties of the plates and the welding consumables, which were produced by the Indian industry, have been studied at 873 and 923 K. Creep rupture strength of the weld joint was found to be comparable with that of the base metal, implying a weld strength reduction factor close to unity. Creep rupture strength of the weld metal was found to be lower than that of the weld joint at 923 K whereas it was comparable to that of the weld joint at 873 K. The creep failure location shifted from the base metal to the weld metal with increase in test temperature from 873 K to 923 K. The base metal and the weld joint satisfied the average strength requirements specified by RCC-MR code. Addition of nitrogen was found to increase rupture strength by about 35% as compared to that of 316 SS. Rupture elongation decreased in the order base metal > weld joint > weld metal. Phenomenological observations on creep behaviour have been rationalized based on the mechanistic aspects of deformation and damage and microstructural changes.

scholarly journals PENGARUH MEDIA PENDINGINAN TERHADAP KEKERASAN DAN STRUKTUR MIKRO HASIL PENGELASAN OXY ACETYLENE PADA MATERIAL BAJA ST-37

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Made Angga Priadi ◽  
I Nyoman Pasek Nugraha ◽  
Gede Widayana
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Quantitative Research ◽  
Welding Process ◽  
Air Cooling ◽  
Water Cooling ◽  
Independent Variable ◽  
The Mean ◽  
Cooling Media

Media pendingin merupakan suatu substansi yang berfungsi dalam menentukan kecepatan pendinginan yang dilakukan terhadap material yang telah diuji dalam perlakuan panas. Penelitian ini bertujuan untuk mengetahui tingkat kekerasan dan pengamatan struktur mikro material baja ST-37 yang dipengaruhi media pendinginan air, udara dan oli serta penelitian ini dapat memberikan bahan referensi bagi lingkup pendidikan teknik mesin dan sebagai acuan di dunia industri dalam menggunakan media pendingin pada proses pengelasan. Adapun jenis metode yang digunakan dalam penelitian ini adalah metode penelitian eksperimen. Terdapat dua jenis variable yang digunakan dalam penelitian ini yaitu variabel bebas yang berupa media pendingin air, media pendingin udara dan media pendingin oli dan variabel terikatnya berupa sifat kekerasan. Dari hasil penelitian yang telah dilakukan dimana kekerasan daerah logam induk dengan media pendingin air memperoleh nilai rata-rata sebesar 63,10 Kg/mm2, pendingin udara memperoleh nilai rata-rata sebesar 65,61 Kg/mm2, dan media pendingin oli memperoleh nilai rata-rata sebesar 62,68 Kg/mm2. Kekerasan pada daerah HAZ dengan media pendingin air memperoleh nila rata-rata sebesar 68,49 Kg/mm2, media pendingin udara memperoleh nilai rata-rata sebesar 71,05 Kg/mm2 dan media pendingin oli memperoleh nilai rata-rata sebesar 70,34 Kg/mm2. Kekerasan pada daerah logam las dengan media pendingin air memperoleh nilai rata-rata sebesar 60,99 Kg/mm2, media pendingin udara memperoleh nilai rata-rata sebesar 61,79 Kg/mm2 dan media pendingin oli memperoleh nilai rata-rata sebesar 60,79 Kg/mm2. Berdasarkan dari hasil yang telah didapatkan baik pada logam induk, daerah HAZ dan logam Las dimana tingkat kekerasan yang lebih baik diperoleh dari proses pendinginan udara dibandingkan dengan media pendingin air dan media pendingin oli dari proses pengelasan oxy acytelene.Kata Kunci : Baja ST-37, Kekerasan Material, media pendinginan. The cooling media is a substance which has a function to determine the speed refrigeneration which carried out of the material that has been tasted by heat treatment. The objective of the research is to know the level of hardness and the observation of steel ST-37 material which is affected by cooling media such as water, air, and oil. Also this research may give a reference for Engineering Department of Education and industry in using cooling media for welding process. There is a method that use in this research, that is called quantitative research. There are two variables that use in this research. Independent variable and dependent variable. An independent variable are water, air, and oil cooling media. On the other hand, a dependent variable is nature of hardness. In this research the researcher got a results where the mean of hardness of the base metal area with the water cooling media is 63.10 Kg/mm2, in air conditioning is 61Kg/mm2, and the oil cooling is 62.68 Kg/mm2. The mean of a hardness in Heat Affected Zone (HAZ) by water cooling media 68,49 Kg/mm2, air cooling media is 71,05 Kg/mm2 and an air cooling is 70,34 Kg/mm2. The mean of Hardness in the weld metal area with water cooling media is 60,99 Kg/mm2, air-cooling media is 61,79 Kg/mm2 and oil-cooling media is 60,79Kg/mm2. Based on the result which has been gotten from base metal, Heat Affected Zone (HAZ), and weld metal where the best hardness level is obtained from air-cooling process rather than water cooling media and oil cooling media from oxy acytelene welding process.keyword : Cooling media, steel ST-37, hardness properties.

Effect of silver nanoparticle (AgNp) mixed with calcium carbonate on impact, hardness and tensile strength properties of aluminium 6063

2020 ◽  
pp. 002199832092314
Author(s):  
Adefemi Adeodu ◽  
Lateef Mudashiru ◽  
Ilesanmi Daniyan ◽  
Abdulmalik Awodoyin
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Aluminium Alloy ◽  
Testing Machine ◽  
Charpy Impact ◽  
Stir Casting ◽  
Optical Microscope ◽  
Tensile Testing Machine ◽  
Casting Technique ◽  
The Impact

Mechanical properties (impact, hardness and tensile strength) characterization of samples containing homogenous mixtures of Al 6063 matrix and varying amount of silver nanoparticles mixed with calcium carbonate at 2, 4, 6% weight fractions, respectively, produced by method of stir casting were carried out. Measurement of impact energy, hardness and tensile strength of the produced samples at 24℃ (ambient) temperature was done by Charpy impact, Brinell hardness and universal tensile testing machine in accordance to ASTM E23, E384 and E8/E8M-13M, respectively. The magnitude of impact and hardness increased evidently with increase in percentage weight fraction of the AgNPs. The refined samples were examined under an optical microscope. The fracture surfaces of the impact test samples were further examined by scanning electron microscopy. There is an increase in tensile strength, elongation and modulus of elasticity of Al-AgNP composites compared to as-cast aluminium alloy. The use of stir-casting technique influences the homogeneity and microstructure of the composites positively. It is concluded that Al-silver nanocomposites possess better qualities in hardness and strength and can replace conventional aluminium alloy in terms of performance and longer life in industrial application.

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