Microstructure and Charpy impact properties of ferrite–martensite dual phase API X70 linepipe steel

Zidelmel, Sami; Sahraoui, Tahar; Hadji, Mohamed

doi:10.1016/j.msea.2014.01.052

Cited by 29 publications

(11 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Then, single‐phase austenite is cooled to the intercritical region and held, where ferrite nucleates at the grain boundaries of austenite and grows within the austenite grains. Such a ferrite–austenite mixture results in a DP microstructure after water quenching which typically consists of blocky and banded martensite embedded in a equiaxed ferrite matrix, as also observed in previous studies . Kerbs et al demonstrated that formation of banded structure in the step quenched DP steels is related to the influence of Mn segregation on the nucleation and growth of ferrite from austenite during cooling from austenitization temperature to intercritical temperature.…”

Section: Resultssupporting

confidence: 63%

“…Das and Chattopadhyay reported that fine and fibrous martensite obtained by IQ provides the best combination of strength and ductility, along with the lowest yield ratio and the highest magnitude of work hardening, which are desirable properties for DP steels. Sami et al found that DP steel produced by IQ treatment exhibited the best impact properties as expressed by its lowest ductile–brittle transition temperature and highest upper‐shelf energy values. The results of other studies also demonstrated that IQ treatment provides the most desirable mechanical properties in DP steels.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Heat Treatment Schedule on the Tensile Properties and Wear Behavior of Dual Phase Steels

Ashrafi

Sadeghzade

Emadi

et al. 2016

steel research int.

View full text Add to dashboard Cite

The aim of present study is to investigate the influence of heat treatment schedule on the microstructure, tensile properties, and wear behavior of dual phase (DP) steels. In this regard, a cold‐rolled low carbon steel (0.18% C, 1.25% Mn) is subjected to intercritical annealing (IA), step quenching (SQ), and intermediate quenching (IQ) heat treatment cycles to produce DP steels with different microstructures. The results show that the tensile strength, strength‐elongation balance, and wear resistance of DP steels change in the order of SQ < IA < IQ. Variation of work hardening rate (θ = dσ/dϵ) with stress for the IA treated DP steel shows a one stage behavior corresponding to stage III, where θ linearly decreases with increasing flow stress. In contrast, for IQ and SQ treated specimens, a two stage behavior corresponding to an initial rapid decrease of θ with stress (transition stage) followed by stage III hardening are observed. The dominant wear mechanism for DP steels produced by IA and IQ treatments is a combination of abrasion and oxidation, while for the SQ treated specimen, a combination of oxidation and delamination is observed.

show abstract

Section: Resultssupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Influence of Heat Treatment Schedule on the Tensile Properties and Wear Behavior of Dual Phase Steels

Ashrafi

Sadeghzade

Emadi

et al. 2016

steel research int.

View full text Add to dashboard Cite

show abstract

“…It can be observed that the quenched and tempered steel (X70Q) presented the best performance, i.e., a 50% increase in fracture toughness compared to the normalizing steel (X42N) and an increase of almost 80% in relation to the hot rolled steel (X42R). This fact is again due to its microstructure [13][14][15][16][17][18][19][23][24][25][26][27][28][29][30][31][32][33][34][43][44][45][46][47][48][49][50][51][52][53] , consisting of tempered martensite, bainite and precipitated carbides.…”

Section: Steel Grade Ae (J)mentioning

confidence: 99%

Evaluation of Microstructure and Mechanical Properties of Seamless Steel Pipes API 5L Type Obtained by Different Processes of Heat Treatments

2017

View full text Add to dashboard Cite

This research presents the influence of manufacturing processes and heat treatments on the resulting microstructures and mechanical properties of an API 5L PSL2 seamless steel pipe. Three different conditions are considered -as rolled, normalized and quenched and tempered -to obtain the grades X42R, X42N and X70Q, respectively. Scanning electron microscopy techniques was used to characterize the resultant microstructures. Tensile, hardness, impact, fracture toughness (J integral) and fatigue crack growth tests (da/dN x ΔK) were used to study the materials mechanical behavior. The results show the possibility of achieving API grades for a seamless pipeline steel, through suitable heat treatments. The microstructural modifications and mechanical properties changes observed showed a remarkable structure-properties relationship of the steel, and attempt to a proper selection as required by the structural design. The quenching and tempering process increased tensile mechanical properties and fracture toughness, but combined to a significant decrease in fatigue crack growth resistance.

show abstract

“…A Figura 4 (a) mostra uma estrutura constituída por ferrita e perlita, típica de um tratamento térmico de normalização, bem diferente das demais condições. Estesconstituintes conhecidamente contribuempara o aumento da ductilidade do materialquando comparados a outros como a bainita e a martensita [10]. As propriedades mecânicas avaliadas neste estudo corroboram com as características da microestrutura observada, pois a amostra normalizada apresentou o maior alongamento e menores valores de LE e LR comparada às demais, assim como uma boa tenacidade ao impacto a 0 o C. A microestrutura da condição NT pode ser observada na Figura 4 (b) onde identificar a presença de bainita e martensitacomo pequena fração de ferrita primária nos contornos de grão prévio da austenita (ferritaalotriomorfa).…”

Section: Microestruturaunclassified

“…Os tratamentos térmicos de têmpera e revenimento são conhecidos por aumentarem a dureza e a resistência mecânica de aços, já a normalização gera um refinamento na microestrutura de ligas que possibilita a melhoria de algumas propriedades mecânicas [4,9]. Estas, entre outras possibilidades de tratamentos térmicos,vêm sendo estudadas em aços microligados visando alcançar propriedades que os classifiquem pelas normas API [10,11]. Considerando a importância das propriedades mecânicas e da microestrutura de aços API para a indústria de petróleo e gás, neste trabalho, visou-se estudar o efeito de alguns tratamentos térmicos sobre estas características de um aço microligado com o objetivo de adequação da sua rota industrial de processamento para atendimento do grau API X65 linepipe, visando qualificá-lo para aplicação na indústria de óleo e gás.…”

Section: Introductionunclassified

Efeito De Alguns Tratamentos Térmicos Sobre a Microestrutura E Propriedades Mecânicas De Um Aço Microligado

Muniz¹,

Mendes²,

Filho³

et al. 2017

Anais Do Enemet - Encontro Nacional De Estudantes De Engenharia Metalúrgica, De Materiais E De Minas

View full text Add to dashboard Cite

ResumoO presente trabalho estudou a influência de alguns tratamentos térmicos sobre a microestrutura e as propriedades mecânicas de um aço microligado visando à adequação de parâmetros que o classifiquem como um ao do tipo API X65 paraaplicação na prospecção e condução de óleo e gás. Diferentes ciclos de tratamentos térmicos envolvendo normalização, têmpera e revenimento foram aplicados a amostras deste aço. Estas foram submetidas a ensaios de tração, dureza Vickers e impacto Charpy, além de terem sido microestruturalmente caracterizadas com o auxílio de microscopia ótica e eletrônica de varredura. Observou-se que as microestruturas e propriedades mecânicas foram fortemente influenciadas pelos tratamentos estudados. Entretanto, apenas a amostra temperada e revenida atendeu integralmente aosrequisitos para o grau API X65no que diz respeito às propriedades mecânicas.Estaamostratambémapresentou maior a tenacidade ao impacto, o que está associado ao alívio de tensões e à decomposição da martensitae da bainita em carbonetos de ferro e ferrita. A amostra normalizada apresentou microestrutura constituída por perlita e ferrita, possuindo assim os menores limites de resistência mecânica e a maior ductilidade. Já nas espécies normalizada-temperada, assim como na simplesmente temperada, observou-semartensita e bainitacomo principais constituintes, supondo-se a presença de uma pequena fração de constituinte MA. Palavras-chave:Aço microligado; Tratamentos térmicos; API X65. EFFECT OF SOME HEAT TREATMENTS ON THE MICROSTRUCTURE AND MECHANICAL PROPRIETIES OF A MICROALLOYED STEEL AbstractThe present work studied the influence of some heat treatments on microstructure and mechanical proprieties of a microalloyed steel aiming to adequate its properties to get the API X65 grade, to possibility its application in oil and gas industry.Tensile tests, Vickers hardness and Charpyimpacttests were performed, as well structural characterization byoptical and scanning electron microscopy. It was observed that steel microstructure and mechanical properties were significantly affected by the studied heat treatments. However, only the quenched and tempered specimen fulfilled the API X65 level in terms of mechanical proprieties. This sample also presented the higher toughness assigned to stress relieving and decomposition of the martensite and bainite in iron carbides and ferrite. The normalized sample exhibited microstructure composed of perlite and ferrite, thus having the lowesttensile strength parameters and the highest ductility. On normalized-quenchedandquenchendspecimens,martensite and bainite were observed as the main steel constituents with a small amount of MA.

show abstract

Microstructure and Charpy impact properties of ferrite–martensite dual phase API X70 linepipe steel

Cited by 29 publications

References 18 publications

Influence of Heat Treatment Schedule on the Tensile Properties and Wear Behavior of Dual Phase Steels

Influence of Heat Treatment Schedule on the Tensile Properties and Wear Behavior of Dual Phase Steels

Evaluation of Microstructure and Mechanical Properties of Seamless Steel Pipes API 5L Type Obtained by Different Processes of Heat Treatments

Efeito De Alguns Tratamentos Térmicos Sobre a Microestrutura E Propriedades Mecânicas De Um Aço Microligado

Contact Info

Product

Resources

About