Optimisation of intermediate heat treatments and stress relief of CrMoV steels

Clerge, M.; Boucher, Christian; Pillot, Sylvain; Balladon, P.; Bourges, P.; Bertoni, Anna Marta Maria

doi:10.1533/wint.2005.3495

Cited by 3 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Literature regarding low-alloyed 2.25Cr-1Mo-0.25V weld metal and steel deals a lot with challenges concerning joining, post weld heat treatment, creep damage and repair issues [3,[26][27][28][29][30][31][32] as well as the evolution of carbides during heat treatment [33][34][35]. As a result, only little precise information about the evolution of microstructure in the course of phase transformation and the final microstructure constituents is available.…”

Section: Cooling Ratementioning

confidence: 99%

Microstructural evolution of 2.25Cr-1Mo-0.25V submerged-arc weld metal

et al. 2019

View full text Add to dashboard Cite

Heat-resistant V-modified 2.25Cr-1Mo-0.25V-weld metal is commonly used in petrochemical industry for heavy wall pressure vessels in high-temperature hydrogen service. In order to improve the reactor efficiency, the weldments have to endure even higher temperatures and pressures. Acicular ferrite (AF) is often regarded as the optimum microstructure due to its good combination of strength and toughness. As few literature about the evolution of microstructure and the final microstructure constituents of 2.25Cr-1Mo-0.25V weld metal is available, the current paper intends to provide comprehensive information by means of microscopy, crystallographic examination via electron backscatter diffraction and in situ observation of the austenite to ferrite phase transformation via high-temperature laser scanning confocal microscopy (HT-LSCM). The investigated weld metal exhibits a high density of complex aluminium-silicon-manganese oxides with a spherical shape and large prior austenite grains, which in combination is beneficial for intragranular nucleation of AF. Nonetheless, the examination of the transformed final microstructure was not sufficient to make an unambiguous statement about the presence of AF within the 2.25Cr-1Mo-0.25V weld metal. Via in-situ HT-LSCM of the phase transformation, intragranular nucleation of AF at non-metallic inclusions within the austenite grains was detected, which confirms that even though the microstructure of 2.25Cr-1Mo-0.25V weld metal is mainly bainitic, small amounts of AF are present.

show abstract

Section: Cooling Ratementioning

confidence: 99%

Microstructural evolution of 2.25Cr-1Mo-0.25V submerged-arc weld metal

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Common PWHT-temperatures are 705 ± 14 °C and the advised minimum PWHT-time is 8 h, as described in API recommended practice 934-A [23]. In general, the PWHT has two main functions which are the softening of the weld metal and the relief of stresses resulting from welding [26,27]. In addition, the PWHT stabilizes the weld metals microstructure by carbide and carbonitride precipitation and improves its properties for the subsequent application under creep loading conditions [27,28].…”

Section: Introductionmentioning

confidence: 99%

On the impact of post weld heat treatment on the microstructure and mechanical properties of creep resistant 2.25Cr–1Mo–0.25V weld metal

et al. 2021

View full text Add to dashboard Cite

Creep resistant low-alloyed 2.25Cr-1Mo-0.25V steel is typically applied in hydrogen bearing heavy wall pressure vessels in the chemical and petrochemical industry. For this purpose, the steel is often joined via submerged-arc welding. In order to increase the reactors efficiency via higher operating temperatures and pressures, the industry demands for improved strength and toughness of the steel plates and weldments at elevated temperatures. This study investigates the influence of the post weld heat treatment (PWHT) on the microstructure and mechanical properties of 2.25Cr-1Mo-0.25V multi-layer weld metal aiming to describe the underlying microstructure-property relationships. Apart from tensile, Charpy impact and stress rupture testing, micro-hardness mappings were performed and changes in the dislocation structure as well as alterations of the MX carbonitrides were analysed by means of high resolution methods. A longer PWHT-time was found to decrease the stress rupture time of the weld metal and increase the impact energy at the same time. In addition, a longer duration of PWHT causes a reduction of strength and an increase of the weld metals ductility. Though the overall hardness of the weld metal is decreased with longer duration of PWHT, PWHT-times of more than 12 h lead to an enhanced temper resistance of the heat-affected zones (HAZs) in-between the weld beads of the multi-layer weld metal. This is linked to several influencing factors such as reaustenitization and stress relief in the course of multi-layer welding, a higher fraction of larger carbides and a smaller grain size in the HAZs within the multi-layer weld metal.

show abstract

Effect of post weld heat treatment on mechanical properties of pressure vessel steels

Калыанкар

Chudasama

2018

Materials Today: Proceedings

View full text Add to dashboard Cite

Optimisation of intermediate heat treatments and stress relief of CrMoV steels

Cited by 3 publications

References 1 publication

Microstructural evolution of 2.25Cr-1Mo-0.25V submerged-arc weld metal

Microstructural evolution of 2.25Cr-1Mo-0.25V submerged-arc weld metal

On the impact of post weld heat treatment on the microstructure and mechanical properties of creep resistant 2.25Cr–1Mo–0.25V weld metal

Effect of post weld heat treatment on mechanical properties of pressure vessel steels

Contact Info

Product

Resources

About