Optimization of strength, ductility and wear resistance of low-carbon grade A shipbuilding steel by post-ECAP annealing

2021 ◽  
Vol 118 (2) ◽  
pp. 217
Author(s):  
M. Demirtas ◽  
D.M. Sekban
Keyword(s):  
Wear Resistance ◽  
Annealing Treatment ◽  
High Hardness ◽  
Coarse Grained ◽  
Low Carbon ◽  
Initial Sample ◽  
Shipbuilding Steel ◽  
Factors Affecting ◽  
Angular Pressing ◽  
Refined Microstructure

Effect of equal channel angular pressing (ECAP) and subsequent annealing on the microstructure, mechanical properties and tribological behavior of grade A shipbuilding steel was investigated. Coarse-grained microstructure of initial sample is eliminated during the ECAP at 375 °C and more refined microstructure is achieved. Post-ECAP annealing at 575 °C results in some grain growth, and also the cementite lamellae in the pearlite colonies is broken and got spheroidised during the annealing treatment. ECAP increases strength and hardness of steel significantly while it decreases the ductility. On the other hand, post-ECAP annealing treatment brings about an increase in ductility and diminishes the hardness, as expected. Strain hardening capacity, ductility, hardness and oxidation rate were found to be the main factors affecting wear resistance of the grade A steel. It was found that high hardness and strength, good wear resistance with sufficiently high ductility can be achieved in the grade A steel by applying ECAP + annealing processes.

Laser Assisted High Entropy Alloy Coating on Low Carbon Steel

2019 ◽  
Vol 813 ◽  
pp. 159-164
Author(s):  
Carlos Alberto Souto ◽  
Gustavo Faria Melo da Silva ◽  
Laura Angelica Ardila Rodriguez ◽  
Aline C. de Oliveira ◽  
Kátia Regina Cardoso
Keyword(s):  
Wear Resistance ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Hardness ◽  
Alloy Coating ◽  
High Entropy Alloy ◽  
Nominal Composition ◽  
Low Carbon ◽  
High Entropy ◽  
Scan Speed

Coatings with high entropy alloys of the AlCoCrFeNiV system were obtained by selective laser melting on low carbon steel substrates. The effect of the variation of the Fe and V contents as well as the laser processing parameters in the development of the coating were evaluated. The coatings were obtained from the simple powder mixtures of the high purity elemental components in a planetary ball mill. The coatings were obtained by using CO2 laser with a power of 100 W, diameter of 0.16 mm, and scan speed varying from 3 to 12 mm/s. Phase constituents, microstructure and hardness were investigated by XRD, SEM, and microhardness tester, respectively. Wear resistance measurements were carried out by the micro-abrasion method using ball-cratering tests. The coatings presented good adhesion to the substrate and high hardness, of the order of 480 to 650 HV. Most homogeneous coating with nominal composition was obtained by using the higher scan speed, 12 mm/s. Vanadium addition increased hardness and gave rise to a high entropy alloy coating composed by BCC solid solutions. Ball cratering tests conducted on HEA layer showing improvement of material wear resistance, when compared to base substrate, decreasing up to 88% its wear rate, from 1.91x10-6 mm3/Nmm to 0.23x10-6 mm3/Nmm.

Effect of Equal Channel Angular Pressing and Annealing on Corrosion Resistance of Al-Cu Alloy

2013 ◽  
Vol 803 ◽  
pp. 226-229
Author(s):  
Da Ran Fang ◽  
Chun Liu ◽  
Feng Fang Liu
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Cu Alloy ◽  
Low Temperature Annealing ◽  
Ultrafine Grained

Al-3.9wt.%Cu alloy was subjected to equal channel angular pressing (ECAP) and subsequent low temperature annealing treatment, and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained alloy increases, in comparison with the coarse-grained alloy. Meanwhile, it is noted that the corrosion resistance of the alloy subjected to ECAP can be improved by relief annealing.

scholarly journals Effect of B Content on Microstructure and Wear Resistance of Fe-3Ti-4C Hardfacing Alloys Produced by Plasma-Transferred Arc Welding

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 265 ◽  
Author(s):  
Lin Zong ◽  
Ning Guo ◽  
Rongguang Li ◽  
Hongbing Yu
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Lath Martensite ◽  
Testing Machine ◽  
High Hardness ◽  
Wear Testing ◽  
Low Carbon ◽  
Hardfacing Alloy ◽  
Plasma Transferred Arc ◽  
Transferred Arc

The Fe-3Ti-xB-4C (x = 1.71, 3.42, 5.10, 6.85 wt. %) hardfacing alloys are deposited on the surface of a low-carbon steel by plasma transferred arc (PTA) weld-surfacing process. Microstructure, hardness and wear resistance have been investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), Rockwell hardness tester and abrasive wear testing machine, respectively. The results show that the microstructure in all alloys is composed of austenite, martensite, Fe23(C,B)6, Ti(C,B) and Fe2B. The volume fraction of eutectic borides and Ti(C,B) carbides increases with increasing B content. Many brittle bulk Fe2B phase arises when the boron content increases to 6.85%, which causes the formation of microcracks in the hardfacing layer. The microhardness of the hardfacing alloys is significantly improved with the B addition, however, the wear resistance of hardfacing alloys increases firstly and then decreases with increasing of B content. The hardfacing alloy with the 5.10% B content has the best wear resistance, which is attributed to high volume fraction of eutectic borides and fine Ti(C,B) particles distributed in the austenite and lath martensite matrix with high hardness and toughness. The formation of brittle bulk Fe2B particles in the hardfacing alloy with the 6.85% B leads to the fracture and spalling of hard phases during wear, thus, reducing the wear resistance.

scholarly journals Investigation into the micro deep drawing capabilities of a specially engineered refined aluminium alloy

2018 ◽  
Vol 190 ◽  
pp. 10001
Author(s):  
A. Dhal ◽  
S.K. Panigrahi ◽  
M.S. Shunmugam
Keyword(s):  
Deep Drawing ◽  
Deformation Behaviour ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Strain Response ◽  
Post Mortem ◽  
Strain Localisation ◽  
Micro Deep Drawing ◽  
Refined Microstructure ◽  
Wide Range

During miniaturisation, size of the part comes close to grain size of the material. There is an overall decrease in the total number grains undergoing deformation and most of these are surface grains. Therefore, microscale deformation is marked by abnormal stress-strain response which limits the manufacturing capabilities of microforming. Two distinct phenomena responsible for this are: (i) dominance of single crystal deformation behaviour, and (ii) increased strain localisation due to incompatibly between surface and core grains during deformation. The present work attempts to neutralise these effects by increasing the number of grains in the deformation zone. This has been achieved by engineering refined microstructure in the materials. To develop the refined microstructure, cryorolling followed by controlled annealing treatment has been employed. Microscale deformation behaviour and microforming capabilities of the refined material have been compared with its coarse-grained counterpart by analysing their tensile curves and by post-mortem study of micro deep drawn components over a wide range of sample thicknesses. Material with fully recrystallised, equiaxed, strain-free refined microstructure is found to have the best strain hardening response both in micro and macro deformation domains. This property is also reflected in the micro deep drawing capabilities of the same material.

scholarly journals Microstructure and Wear Behavior of In-Situ NbC Reinforced Composite Coatings

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3459 ◽  
Author(s):  
Baoming Shi ◽  
Shiming Huang ◽  
Ping Zhu ◽  
Changen Xu ◽  
Tengfei Zhang
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Niobium Carbide ◽  
Low Carbon Steel ◽  
High Hardness ◽  
Low Carbon ◽  
Micro Hardness

In the present study, plasma spray welding was used to prepare an in-situ niobium carbide (NbC) reinforced Ni-based composite coating on the low carbon steel, and the phase composition and the microstructure of the composite coatings were studied. The wear resistance and the wear mechanism of the composite coatings were also researched by the wear tests. The results showed that the main phases of the composite coating were NbC, γ-Ni, Cr23C6, Ni3Si, CrB, Cr5B3, Cr7C3 and FeNi3. A number of fine in-situ NbC particles and numerous chromium carbide particles were distributed in the γ-Ni matrix. The increase in the mass fraction of Nb and NiCr-Cr3C2 could lead to the increase in NbC particles in the composite coatings. Due to the high hardness of NbC and chromium carbides, the micro-hardness and the wear resistance of the composite coatings were advanced. The composite coating with the powder mixtures of 20% (Nb + NiCr-Cr3C2) and 80% NiCrBSi had the highest micro-hardness and the best wear resistance in this study. The average micro-hardness reached the maximum value 1025HV0.5. The volume loss was 39.2 mm3, which was merely 37% of that of the NiCrBSi coating and 6% of that of the substrate under the identical conditions.

Effect of Equal Channel Angular Pressing and Annealing on Corrosion Resistance of Cu-Zn Alloy

2013 ◽  
Vol 706-708 ◽  
pp. 78-81 ◽  
Author(s):  
D.R. Fang ◽  
F.F. Liu ◽  
Chun Liu
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Ultrafine Grained ◽  
Zn Alloy

Cu-32wt.%Zn alloy was subjected to equal channel angular pressing (ECAP) and subsequent low temperature annealing treatment, and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained alloy decreases, in comparison with the coarse-grained alloy. Meanwhile, it is noted that the corrosion resistance of the sample subjected to ECAP can be further improved by relief annealing.

Wear Behaviors of Nano Grained Aluminum Alloys

2008 ◽  
Vol 47-50 ◽  
pp. 702-705
Author(s):  
Won Sik Lee ◽  
Keun Song ◽  
Jin Man Jang ◽  
Se Hyun Ko ◽  
Il Ho Kim
Keyword(s):  
Wear Resistance ◽  
Applied Load ◽  
High Hardness ◽  
Coarse Grained ◽  
High Wear Resistance ◽  
Sliding Velocity ◽  
Grain Sizes ◽  
Predominant Factor ◽  
Fracturing Mechanism ◽  
Nano Grains

Some nano grained Al materials were produced by mechanical milling/alloying followed by vacuum hot pressing: nano grained pure Al, Al-1.5Mg and Al-0.7Mg-1.0Cu alloys in wt%. The nano bulk materials had average grain sizes of 90-150 nm and ball-on-disk wear equipment was used to investigate the effects of grain size comparing to coarse grained pure Al and T6-treated Al 6061 alloy. In comparison of coarse and nano grained pure Al materials, nano grained specimens showed much higher wear resistance and size of wear debris was very fine as much as 100 nm at applied load of 100g. Wear in nano grained materials proceeded by micro fracturing mechanism like abrasion in low applied and sliding velocity and the mechanism resulted in high wear resistance. Nano grained Al-1.5Mg and Al-0.7Mg-1.0Cu alloys showed much superior wear characteristics due to nano grains and high hardness. As a result, size of grains was a predominant factor for high resistance at low applied load and/or sliding velocity, while hardness at higher applied load or velocity.

The microstructure change of low-carbon electrical steels by residual aluminum

1989 ◽  
Vol 47 ◽  
pp. 286-287
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee
Keyword(s):  
Annealing Treatment ◽  
Low Carbon ◽  
Electrical Steels ◽  
Vacuum Degassing ◽  
Spherical Inclusions ◽  
Residual Aluminum ◽  
Average Grain Size ◽  
The Matrix ◽  
Fine Size ◽  
To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

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