Damage analysis of extrusion tools made from the austenitic hot work tool steel Böhler W750

Krumphals, Friedrich; Wlanis, Thomas; Sievert, R.; Wieser, Volker; Sommitsch, Christof

doi:10.1016/j.commatsci.2010.04.022

Cited by 8 publications

(7 citation statements)

References 3 publications

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“…The descriptions of damage developed due to creep in materials can also be developed from a phenomenological approach. A number of efforts in this direction have appeared in the literature 77,[88][89][90] . Considering the relationship between the appearance of creep cavitation and the nature of creep curve especially for steels where the secondary creep stage is missing, it can be concluded that creep damage results in an increase of the creep rate.…”

Section: Measures Of Estimating Creep Life In Steels : a Critical Reviewmentioning

confidence: 99%

“…A number of efforts in this direction have appeared in the literature. 81,[92][93][94] Considering the relationship between the appearance of creep cavitation and the nature of the creep curve, especially for steels where the secondary creep stage is missing, it can be concluded that creep damage results in an increase in the creep rate. This rapid increase in creep rate takes place in the tertiary stage.…”

Section: D~smentioning

confidence: 99%

“…Thus the phenomenological approach can be divided into two categories: one that explicitly incorporates the cavitation damage and one that deals with microstructural damage. The Kachanov model 81,[94][95][96] is an example of the former while Dyson and McLean [97][98][99][100] type models are examples of the latter.…”

Section: D~smentioning

confidence: 99%

“…While it has been possible at large synchrotron sources to provide penetration for significantly larger cross-sections at reduced resolution in light metal alloys (e.g. 1·4×1·4 μm for metal matrix composites), 94 no such exercise correlating the resolution to the sample volume appears to have been reported for steels.…”

Section: New Approaches To Residual Life Estimationmentioning

confidence: 99%

“…77,[90][91][92] is an example of the former while Dyson-Mclean[93][94][95][96] type models are examples of the latter.The Robotnov-Kachanov (RK) equations are one of the earliest ones to use the concept of damage in the development of constitutive equations describing creep behaviour in materials.It uses a parameter 'ω' denoting damage as a scalar variable that varies between 0 to 1 as the material creeps to failure. As the creep rates at a given temperature are influenced by stress and the extent of damage developed in the material, two rate equations are required to formulate the creep constitutive equations.…”

mentioning

confidence: 99%

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3D creep cavitation characteristics and residual life assessment in high temperature steels: A critical review

Gupta

Toda

Mayr

et al. 2015

Materials Science and Technology

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The paper seeks to assess critically the need for a new paradigm in creep life estimation of service exposed steels and provide possible new directions of residual life assessment, in the light of a decade of explosive application of micro-tomography on structural materials to characterise the 3D nature of cavitation damage. The phenomenon of creep failure using synchrotron micro-tomography (SR-µCT) has been studied at large synchrotron sources where imaging on conventional structural materials such as steels with high absorption to X-rays has been realized. The unique feature of the SR-µCT studies is the direct imaging in 3D of cavitation present in the bulk (hundreds of micrometers in size), revealing the spatial characteristics and morphology of the creep voids. Further the quantitative analyses of cavitation characteristics contained in the 3D datasets, which when scaled with time, stress and temperature provides functional information amenable for developing constitutive equations for creep fracture. These being based on SR-µCT, which due to its non-destructive feature provides high fidelity data that significantly reduces the ambiguity in the development of the functional relationships related to creep failure. Thus the use of such constitutive equations in an explicit manner to estimate the residual life of the components affected by creep and the consequent assessment of structural integrity would prove invaluable. This paper summarizes the studies related to creep in materials using micro-tomography with special emphasis on a 10.86%Cr heat resistant steel to show the type of data available which could be relevant for life assessment and design against creep failure. A brief discussion of the existing methods of residual life estimations in the light of the availability of the 3D micro-tomography data available in recent literature follows. Finally the possible new directions of using the microtomography data to formulate advanced residual life estimation methods are briefly touched.

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Section: Measures Of Estimating Creep Life In Steels : a Critical Reviewmentioning

confidence: 99%

Section: D~smentioning

confidence: 99%

Section: D~smentioning

confidence: 99%

Section: New Approaches To Residual Life Estimationmentioning

confidence: 99%

mentioning

confidence: 99%

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3D creep cavitation characteristics and residual life assessment in high temperature steels: A critical review

Gupta

Toda

Mayr

et al. 2015

Materials Science and Technology

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Latest advances in extrusion processes of light metals

Leśniak,

Zasadziński,

Libura

et al. 2024

Arch. Civ. Mech. Eng.

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The paper presents a review of the literature and authors’ research on the current achievements in the field of extrusion of aluminium alloys, magnesium alloys, powders and aluminium-based composites in particular. The microstructure transformations taking place during homogenisation of billets from the medium- and high-strength heat-treatable aluminium alloys are still an object of interest of researchers. The recently published papers are related to dissolution of soluble phases formed during solidification and elimination of microsegregation, precipitation of the dispersoids, insoluble phases’ transformation as well as particles re-precipitation during cooling. The novelties in the extrusion of magnesium alloys and aluminium-based composites are shortly reported. Specifics of the extrusion dies design and their working conditions, which limit the products quality and working life of the tools, are extensively reported. The computer-aided designing (CAD) and finite-element method (FEM) and 3D optical scanning were used in analysis aimed at dimensional deviations of the dies and the extruded products. The surface engineering techniques such as welding techniques, diffusion layers and protective coatings such as produced by physical vapour deposition (PVD), plasma-enhanced physical vapour deposition (PAPVD), chemical vapour deposition (CVD) and plasma-enhanced chemical vapour deposition (PECVD) are described. Various original methods of extrusion including the severe plastic deformation processes (SPD), such as cyclic extrusion compression (CEC), equal-channel angular pressing (ECAP) and hydrostatic extrusion (HE) are discussed. The above techniques as well as the new KOBO extrusion process with oscillating die movement generate significant refining of the microstructure of metals and alloys and enable consolidation of the powdered materials. The application of the rapid solidification process connected with the hot extrusion permits production of beneficial microstructure and above-standard mechanical properties of the extruded products. Finally, the opportunities and directions of development of the extrusion process of metals and alloys are indicated.

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Deformation behaviour of a ferritic hot-work tool steel with respect to the microstructure

Krumphals

Reggiani

Donati

et al. 2012

Computational Materials Science

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Damage analysis of extrusion tools made from the austenitic hot work tool steel Böhler W750

Cited by 8 publications

References 3 publications

3D creep cavitation characteristics and residual life assessment in high temperature steels: A critical review

3D creep cavitation characteristics and residual life assessment in high temperature steels: A critical review

Latest advances in extrusion processes of light metals

Deformation behaviour of a ferritic hot-work tool steel with respect to the microstructure

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