Evaluation of Corrosion, Mechanical Properties and Hydrogen Embrittlement of Casing Pipe Steels with Different Microstructure

In the research, the corrosion and mechanical properties, as well as susceptibility to hydrogen embrittlement, of two casing pipe steels were investigated in order to assess their serviceability in corrosive and hydrogenating environments under operation in oil and gas wells. Two carbon steels with different microstructures were tested: the medium carbon steel (MCS) with bainitic microstructure and the medium-high carbon steel (MHCS) with ferrite–pearlite microstructure. The results showed that the corrosion resistance of the MHCS in CO2-containing acid chloride solution, simulating formation water, was significantly lower than that of the MCS, which was associated with microstructure features. The higher strength MCS with the dispersed microstructure was less susceptible to hydrogen embrittlement under preliminary electrolytic hydrogenation than the lower strength MHCS with the coarse-grained microstructure. To estimate the embrittlement of steels, the method of the FEM load simulation of the specimens with cracks was used. The constitutive relations of the true stress–strain of the tested steels were defined. The stress and strain dependences in the crack tip were calculated. It was found that the MHCS was characterized by the lower plasticity on the stage of the neck formation of the specimen and the lower fracture toughness than the other one. The obtained results demonstrating the limitations of the usage of casing pipes made of the MHCS with the coarse-grained ferrite/pearlite microstructure in corrosive and hydrogenating environments were discussed.

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The Microhardness Analysis of Friction Welded AISI 52100 Grade Carbon Steel Joints

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.984-985.613 ◽

2014 ◽

Vol 984-985 ◽

pp. 613-617

Author(s):

S.T. Selvamani ◽

K. Umanath ◽

K. Palanikumar ◽

K. Vigneswar

Keyword(s):

Mechanical Properties ◽

Carbon Steel ◽

Vickers Hardness ◽

High Carbon Steel ◽

Industrial Applications ◽

Carbon Steels ◽

Hardness Tests ◽

Aisi 52100 ◽

Superior Mechanical Properties ◽

Steel Joints

The solid-state joining process produces welds with improved mechanical properties and reduced distortion. Higher Carbon Steels are extensively used in different industrial applications such as shipbuilding and automobile industries due to their superior mechanical properties. In this work, friction welding of high carbon steel of Φ12mm dia extruded rod was studied with a plan to analysis the hardness behavior on the weldment. Welds are made with a high and low level range of process parameter combinations (incorporating ANOVA methods) which were subjected to Vickers Hardness tests. The Vickers Hardness of the welded joints has been reported.

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Mechanical Properties of Plain Carbon Steels with Ultrafine (α+θ) Microstructures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.682.109 ◽

2011 ◽

Vol 682 ◽

pp. 109-113

Author(s):

Hai Yan Zhu ◽

Long Fei Li ◽

Wang Yue Yang ◽

Zu Qing Sun

Keyword(s):

Mechanical Properties ◽

Carbon Steel ◽

Hot Deformation ◽

Tensile Tests ◽

Total Elongation ◽

Medium Carbon Steel ◽

Carbon Steels ◽

Eutectoid Steel ◽

Medium Carbon ◽

Undercooled Austenite

Mechanical properties of a medium-carbon steel with the ultrafine (α+θ) microstructures obtained by hot deformation of undercooled austenite and annealing were investigated by tensile tests, in comparison with that of a eutectoid steel. The results indicated that in the case of hot deformation of undercooled austenite to strain of 1.61 at 650°C at 0.01s-1 and annealing at 650°C for 30min, the ultrafine (α+θ) microstructures consisting of ultrafine ferrite grains and dispersed cementite particles were similar in the medium-carbon steel and the eutectoid steel, but the mechanical properties of the eutectoid steel were better that maybe be attributed to the relatively coarser size and the higher amount of cementite particles. With the increase of temperature for hot deformation of undercooled austenite to 700°C, the ultrafine (α+θ) microstructure of the medium-carbon steel changed obviously with the presence of some spheroidized pearlite colonies, and demonstrated the best balance of strength and elongation, the yield strength of about 545MPa, the tensile strength of about 635MPa, and the total elongation of about 35%.

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INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING ◽

10.32852/iqjfmme.vol18.iss1.78 ◽

2018 ◽

Vol 18 (1) ◽

pp. 125-135

Author(s):

Sattar H A Alfatlawi

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Surface Roughness ◽

Carbon Steel ◽

Cold Water ◽

Medium Carbon Steel ◽

Medium Carbon ◽

Heating And Cooling ◽

Treatment Processes ◽

Quenching And Tempering

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.

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