The behaviour of surface residual stress relief under impact loading in FC 25 cast iron.

1985 ◽  
Vol 51 (462) ◽  
pp. 534-538
Author(s):  
Akikazu NAKAGIRI ◽  
Haruoki MAEDA ◽  
Kazuya SAWADA
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.


2012 ◽  
Vol 468-471 ◽  
pp. 409-413
Author(s):  
Fu Jin Yu ◽  
Lin Lin Wang

In this paper, the surface residual stress of spheroidal graphite cast iron was measured by using critically refracted longitudinal (LCR) ultrasonic wave, X-ray diffraction (XRD) and blind-hole measurement methods. The test specimens used in this study were cut from a practical forging roller made from spheroidal graphite cast iron. The measurement results were compared and analyzed. They indicated that the measurement results obtained by this LCR method were consistent with those of the other two methods, which verified that for spheroidal graphite cast iron material, LCR method was an applicable, effective and reliable test technology of surface residual stress measurement.


2014 ◽  
Vol 696 ◽  
pp. 70-75 ◽  
Author(s):  
Ying Zi Wang ◽  
Yan Hua Zhao ◽  
Jie Sun

Laser cladding is an effective mean to repair the damaged components in remanufacture industry. The iron-based alloy coating was obtainment by laser cladding on grey cast iron (HT250). The microstructure and morphology of laser cladding were observed by using scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The micro hardness of laser cladding coating was tested. The wear properties of grey cast iron and laser cladding coating at room temperature without lubrication were evaluated by sliding wear tests. The distribution regularity of surface residual stress of substrate and cladding coating was obtained. It was shown that the laser cladding coating on grey cast iron has a homogeneous and dense microstructure. It was observed that the laser cladding coating presents a great hardness and excellent wear resistance. Tensile stress was generated in the surface of laser cladding coating.


2014 ◽  
Vol 783-786 ◽  
pp. 692-697 ◽  
Author(s):  
Andrew Clark ◽  
Randy J. Bowers ◽  
Derek O. Northwood

The effects of heat treatment on distortion, residual stress, and retained austenite were compared for case-carburized 4320 steel, in both the austempered and quench-and-tempered condition. Navy C-ring samples were used to quantify both size and shape distortions, as well as residual stress. The austempering heat treatment produced less distortion and a higher surface residual stress. Both hoop and axial stresses were measured; the difference between them was less than seven percent in all cases. Depth profiles were obtained for residual stress and retained austenite from representative C-ring samples for the austempered and quench-and-tempered heat treatment conditions. Austempering maintained a compressive residual stress to greater depths than quench-and-tempering. Quench-and-tempering also resulted in lower retained austenite amounts immediately beneath the surface. However, for both heat treatments, the retained austenite content was approximately one percent at depths greater than 0.5 mm.


2013 ◽  
Vol 753-755 ◽  
pp. 277-280 ◽  
Author(s):  
Wei Xiang Liu

Nano-ceramic materials had high hardness and wear resistance. Combined with current technology and cost saving, nanostructured coatings technology were carried out, using HVOF ( high velocity oxygen fuel) or plasma spraying technique can obtain high quality ceramic coating on metal substrate. Ceramic coatings produced cracks in the grinding due to grinding surface residual stress. the coatings grinding surface residual stress of engineering ceramics have been researched, grinding surface residual stress in the nanostructured ceramic coatings are being researched. the researches in this field include grinding process modeling, abrasives and grinding parameters, grinding process monitoring and control and realization of the software, the grinding mechanism and grinding damage on the surface, grinding force prediction, on-line detection, grinding on nanocoating material is a multivariable complex process.


2009 ◽  
Vol 24 (S1) ◽  
pp. S22-S25
Author(s):  
Y. B. Guo ◽  
S. Anurag

Hard turning, i.e., turning hardened steels, may produce the unique “hook” shaped residual stress (RS) profile characterized by surface compressive RS and subsurface maximum compressive RS. However, the formation mechanism of the unique RS profile is not yet known. In this study, a novel hybrid finite element modeling approach based on thermal-mechanical coupling and internal state variable plasticity model has been developed to predict the unique RS profile patterns by hard turning AISI 52100 steel (62 HRc). The most important controlling factor for the unique characteristics of residual stress profiles has been identified. The transition of maximum residual stress at the surface to the subsurface has been recovered by controlling the plowed depth. The predicted characteristics of residual stress profiles favorably agree with the measured ones. In addition, friction coefficient only affects the magnitude of surface residual stress but not the basic shape of residual stress profiles.


Sign in / Sign up

Export Citation Format

Share Document