Effects of Laser Peening Treatment on High Cycle Fatigue and Crack Propagation Behaviors in Austenitic Stainless Steel

2009 ◽  
Author(s):  
Yasuo Ochi ◽  
Kiyotaka Masaki ◽  
Takashi Matsumura ◽  
Takaaki Ikarashi ◽  
Yuji Sano
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Layer ◽  
Fatigue Crack ◽  
Fatigue Strength ◽  
Crack Propagation ◽  
Compressive Residual Stress ◽  
High Cycle Fatigue ◽  
Laser Peening ◽  
Cycle Fatigue

Laser peening without protective coating (LPwC) treatment is one of surface enhancement techniques using impact wave of high pressure plasma induced by laser pulse irradiation. One of the effects of the LPwC treatment is expected to reduce the tensile residual stress and to induce the compressive residual stress in the surface layer of metallic materials. As a laser has no reaction force due to irradiation and also it has easy characteristics for remote control, the LPwC treatment is practically used as a technique for preventing the stress corrosion cracking (SCC) and for improving the fatigue strength of some structural materials. In this study, high cycle fatigue tests with four-points rotating bending loading were carried out on the non-peened and the LPwC treated low-carbon type austenitic stainless steel 316L in order to investigate the effects of the LPwC treatment on the high cycle fatigue strength and the surface fatigue crack propagation behavior. Two types of specimens were prepared; one was a smooth specimen, the other was a specimen with a pre-crack by the fatigue loading from a small artificial hole. As the results of the LPwC treatment, the high compressive residual stress was induced in the surface layer on the specimens, and the region of the compressive residual stress was about 1mm depth from the surface. The fatigue strength of the LPwC treated SUS316L was remarkably improved during the whole regime of the fatigue life up to the 108 cycles compared with the non-peened materials. Through the fracture mechanics investigation of the pre-cracked materials after the LPwC treatment, it became clear that the fatigue crack propagation was restrained by the LPwC treatment on the pre-cracked region, when the stress intensity factor range ΔK on the crack tip was under the value of 7.6 MPa√m.

scholarly journals Effects of Laser Peening Treatment on High Cycle Fatigue and Crack Propagation Behaviors in Austenitic Stainless Steel

2010 ◽  
Vol 4 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Kiyotaka MASAKI ◽  
Yasuo OCHI ◽  
Takashi MATSUMURA ◽  
Takaaki IKARASHI ◽  
Yuji SANO
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Crack Propagation ◽  
High Cycle Fatigue ◽  
Laser Peening ◽  
Cycle Fatigue

High-Cycle Fatigue Strength and Residual Stress in Welded Joints of Structural Steels

2004 ◽  
Author(s):  
Masahito Mochizuki ◽  
Masao Toyoda
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Fatigue Strength ◽  
Low Temperature ◽  
Weld Metal ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
High Cycle Fatigue ◽  
Temperature Phase ◽  
Cycle Fatigue

Improvement of high-cycle fatigue strength by reducing residual stress in welded joints is studied in this paper. 10% Nickel and 10% Chromium are involved in the developed welding material for producing the property of thermal shrinkage by martensitic phase transformation at a low temperature and for generating compressive residual stress during cooling process. A cruciform fillet-welded joint is used for the numerical simulation of the thermal elastic-plastic finite-element analysis with coupling phase transformation effect. Distribution of the computed residual stress agrees with the measuring values by strain gauge. Compressive residual stress mostly distributes in the weld metal for both longitudinal and transverse directions with weld line. Fatigue test is also performed in order to clarify the effect of the developed weld material on fatigue strength. Developed weld metal has much higher characteristics for high-cycle fatigue strength than a conventional one. Increase effect of fatigue strength is shown by the modified Goodman diagram when residual stress is treated as mean stress. Weld metal with the property of low-temperature phase transformation is effective to reduce residual stress and to improve fatigue strength.

scholarly journals Effects of Laser Peening Treatment on High Cycle Fatigue Strength and Fatigue Crack Behaviors under Axial Loading of Aluminum Alloy

2010 ◽  
Vol 59 (12) ◽  
pp. 932-937 ◽  
Author(s):  
Yasuo OCHI ◽  
Takashi MATSUMURA ◽  
Takaaki IKARASHI ◽  
Kiyotaka MASAKI ◽  
Toshifumi KAKIUCHI ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Axial Loading ◽  
Laser Peening ◽  
Cycle Fatigue

Enhancement of Surface Properties by Laser Peening Without Coating

2006 ◽  
Author(s):  
Yuji Sano ◽  
Igor Altenberger ◽  
Berthold Scholtes ◽  
Kiyotaka Masaki ◽  
Yasuo Ochi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
High Cycle Fatigue ◽  
Laser Pulses ◽  
Cast Aluminum Alloy ◽  
Laser Peening ◽  
Cycle Fatigue ◽  
Cast Aluminum ◽  
Rotating Bending ◽  
Laser Peening Without Coating

Laser peening without coating (LPwC) has been applied to water-immersed materials using a water-penetrable light of a Q-switched and frequency-doubled Nd:YAG laser. Compressive residual stress of several hundred MPa was introduced at the surface of the materials. High-cycle fatigue (HCF) properties were evaluated through rotating-bending or push-pull type testing for an austenitic stainless steel (SUS316L), a titanium alloy (Ti-6Al-4V) and a cast aluminum alloy (AC4CH). LPwC prolonged the fatigue lives significantly, in spite of the increase in surface roughness ascribed to the ablative interaction of laser pulses with the materials.

Suppression of Fatigue Crack Growth in Austenite Stainless Steel by Cavitation Peening

2010 ◽  
Vol 452-453 ◽  
pp. 641-644 ◽  
Author(s):  
Osamu Takakuwa ◽  
Masaaki Nishikawa ◽  
Hitoshi Soyama
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Modification ◽  
Fatigue Crack ◽  
Fatigue Strength ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Compressive Residual Stress ◽  
Austenite Stainless Steel ◽  
The Impact

Cavitation normally causes severe damage in hydraulic machinery such as pumps and turbines by the impact produced by cavitation bubbles collapsing. Although cavitation is known as a factor of erosion, Soyama et al. succeeded in utilizing impacts of cavitation bubble collapsing for surface modification by controlling cavitating jet in the same way as shot peening. The local plastic deformation caused by cavitation impact enhances the fatigue strength of metallic materials, and the surface modification technique utilizing cavitation impact is called “cavitation peening (CP)”. It is well known that the peening improves fatigue strength by introducing compressive residual stress on the surface, but little attention has been paid to the behavior of fatigue crack growth of the material which was modified by CP. In the present study, the fatigue behavior of austenite stainless steel with and without CP was evaluated by a plate bending fatigue test, and the results revealed that the compressive residual stress introduced by CP suppresses fatigue crack growth rate by 70 % compared to that without CP.

High Cycle Fatigue and Fatigue Crack Propagation Behaviors of Modified A7075-T73 Alloy

2014 ◽  
Vol 52 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Gwan Yeong Kim ◽  
Kyu Sik Kim ◽  
Joong Cheol Park ◽  
Shae Kwang Kim ◽  
Young Ok Yoon ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
High Cycle Fatigue ◽  
Cycle Fatigue

Residual Stress Analysis in Deep Rolling Process on Gas Tungsten Arc Weld of Stainless Steel AISI 316L

2021 ◽  
Vol 880 ◽  
pp. 23-28
Author(s):  
Warinthorn Thanakulwattana ◽  
Wasawat Nakkiew
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Layer ◽  
Compressive Residual Stress ◽  
Aisi 316L ◽  
Deep Rolling ◽  
Gas Tungsten Arc ◽  
Steel Aisi ◽  
Gas Tungsten ◽  
Stainless Steel Aisi

Because of the general problem of the welding workpiece such as fatigue fracture caused by tensile residual stress lead to initial and propagation crack in the fusion zone. Thus, the mechanical surface treatment of deep rolling on Gas Tungsten Arc Welded (GTAW) surfaces of AISI 316L was studied. Deep rolling (DR) is a cold working process to induce compressive residual stress in the surface layer of the workpiece resulting in hardening deformation which increased surface hardness, and smooth surface that inhibit crack growth and improve fracture strength of materials. The present study focuses on compressive residual stress at the surface of stainless steel AISI 316L butt welded joint of GTAW. The three parameters of DR process were used; pressure 150 bar, rolling speed 400 mm/min, and step over 1.0 mm. The residual stresses analysis by X-ray diffraction with sin2Ψ method at 0, 5, 10, and 20 mm from the center of the welded bead. The results showed that the DR process on the welded of GTAW induce the minimum compressive residual stress-408.6 MPa and maximum-498.1 MPa in longitudinal direction. The results of transverse residual stress in minimum and maximum are 43.7 MPa and-34.8 MPa respectively. The FWHM of DR both longitudinal and transverse direction were increased in the same trend. Furthermore, the microhardness after DR treatment on workpiece surface layer higher than GTAW average 0.4 times.

Sign in / Sign up

Export Citation Format

Share Document