Author: Lawrence MolinaroPublisher:
ISBN:
Category : Cast-iron
Languages : en
Pages : 150
Book Description
Fatigue Behavior and Crack Development in Compacted Graphite Cast Iron
Author: Lawrence MolinaroPublisher:
ISBN:
Category : Cast-iron
Languages : en
Pages : 150
Book Description
Fatigue Crack Initiation and Growth in Gray Cast Iron
Author: James Walter FashPublisher:
ISBN:
Category : Cast-iron
Languages : en
Pages : 132
Book Description
Transactions of the American Foundrymen's Society
Author: Residual stresses, fatigue and deformation in cast iron
Author: Mattias LundbergPublisher: Linköping University Electronic Press
ISBN: 9176853586
Category :
Languages : en
Pages : 59
Book Description
The complex geometry of cylinder heads in heavy-duty diesel engines makes grey iron or compact graphite iron a preferred material choice due to its price, castability, thermal conductivity and damping capacity. Today’s strict emission laws have increased the demands on engine performance and engine efficiency. This means that material properties such as fatigue resistance need to be improved. Shot peening is often used to improve the fatigue resistance of components and the benefits of shot peening are associated with the induced compressive surface stresses and surface hardening. How different shot peening parameters can affect fatigue strength of grey and compact graphite iron has been investigated within the project underlying this thesis. To do this, X-ray diffraction (XRD) was utilized for residual stress measurements, scanning electron microscopy (SEM) for microstructural characterizations and mechanical fatigue testing for mechanical quantifications. The ultimate aim of this work has been to increase the fatigue resistance of cast iron by residual stress optimization. XRD measurements and SEM examinations revealed that the shot peening parameters shot size and peening intensity significantly influence residual stresses and surface deformation. Residual stress profiles, similar to the one general considered to improve the fatigue strength in steels, were obtained for both grey and compact graphite iron. Uniaxial push-pull fatigue testing on grey iron with these shot peening parameters reduced the fatigue strength with 15–20 %. The negative effect is likely related to surface damage associated with over peening and relatively high subsurface tensile residual stresses. With very gentle shot peening parameters, the uniaxial fatigue strength were unaltered from the base material but when subjected to bending fatigue an increase in fatigue strength were observed. An alternative way to increase the fatigue strength was to conduct a 30 min annealing heat treatment at 285 XC which increased the fatigue strength by almost 10 % in uniaxial loading. The improvement could be an effect of favourable precipitates forming during the annealing, which could hinder dislocation movement during fatigue. Measuring residual stresses using XRD and the sin2 -method demands accurate X-ray elastic constants (XEC) for meticulous stress analysis. The XEC referred to as 1~2s2 should therefore always be calibrated for the specific material used. The experiments conducted revealed that the XEC value is independent of the testing method used in this work. A small correction from the theoretical value should be applied when the material contains small amounts of residual stresses. The amount of residual stresses has a great impact on the XEC and thus on the stress analysis. Concluding that proper analysis of residual stresses in cast iron is not straight forward.
The Effect of Microstructure on Fatigue Crack Growth Behavior in Nodular Cast Irons
Author: Minxia XiePublisher:
ISBN:
Category : Iron, Modular
Languages : en
Pages : 178
Book Description
Fatigue Design Handbook
Author: Richard C. RicePublisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 400
Book Description
A Unified Predictive Technique for the Fatigue Resistance of Cast Ferrous-based Metals and High Hardness Wrought Steels
Author: Michael Roger MitchellPublisher:
ISBN:
Category : Iron
Languages : en
Pages : 156
Book Description
A technique which treats the free graphite in gray and nodular cast iron, gas pores and microshrinkage cavities in cast steels and inclusions in wrought, high hardness steels as notches in a steel matrix results in quantitative.
Fatigue Crack Growth in Gray Cast Iron Under Block Loading Histories
Author: Gary Burton MarquisCasting Design and Performance
Author: Publisher: ASM International
ISBN: 1615031324
Category : Science
Languages : en
Pages : 271
Book Description
ASM Specialty Handbook
Author: Joseph R. DavisPublisher: ASM International
ISBN: 9780871705648
Category : Technology & Engineering
Languages : en
Pages : 514
Book Description
Cast iron offers the design engineer a low-cost, high-strength material that can be easily cast into a wide variety of useful, and sometimes complex, shapes. This handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all metals.