High temperature fatigue tests and crack growth in 40CrMoV13.9 notched components
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 34
Abstract
The present paper addresses experimentally the high temperature fatigue of 40CrMoV13.9 steel and the effect of surface roughness on fatigue strength and crack initiation. The 40CrMoV13.9 steel is widely used in different engineering high temperature applications among which hotrolling of metals, where, in order to assure a constant temperature, the rolls are provided with cooling channels. These are the most stressed zone of the rolls where cracks systematically initiate. In order to completely characterize the high temperature behaviour of this steel, firstly uniaxial-tension load controlled fatigue tests have been conducted at different temperatures up to 650°C. Two geometries are considered: plain specimens and plates weakened by symmetric V-notches. Subsequently, with the aim to investigate the influence of the cooling channels roughness on the high temperature behaviour and the cracks initiation, uniaxial-tension load controlled fatigue tests have been conducted on plate with central hole at the service temperature of 650°C varying the surface roughness. After a brief review of the recent literature, the experimental procedure is described in detail and the new data from un-notched and notched specimens are summarized in terms of stress range, at the considered temperatures. Finally, fatigue data from un-notched and notched specimens are re-analysed by means of the mean value of the Strain Energy Density (SED) approach extended at high temperature.
Authors and Affiliations
P. Gallo, F. Berto
Study of short cracks under biaxial fatigue
In this paper a methodology for evaluating crack initiation under biaxial conditions is presented. The methodology consists of evaluating the crack length automatically with digital processing of highmagnification...
Development of an engineering methodology for non-linear fracture analysis of impact-damaged pressurized spacecraft structures
Motivated by the dramatic worsening and uncertainty of orbital debris situation, the present paper is focused on the structural integrity of the spacecraft pressurized modules/pressure vessels. The objective is to...
Applicazione della meccanica della frattura viscoelastica alla previsione della vita di tubi in polibutene
Il Polibutene-1 isotattico (i-PB1) è un materiale polimerico usato per la produzione di tubi per il trasporto di fluidi in pressione. In questo lavoro si sono studiati due tipi di i-PB1 prodotti da Basell che diffe...
Functional fatigue of NiTi Shape Memory wires for a range of end loadings and constraints
The availability of engineering strength data on shape memory alloys (SMAs) under cyclic thermal activation (functional fatigue) is central to the rational design of smart actuators based on these materials....
Measurement and simulation of strain fields around crack tips under mixed-mode fatigue loading
For various configurations examined in a series of fatigue experiments on thin-walled tubes under tension and torsion, the experimental results – crack path, crack growth life, near crack tip deformations, and cr...