Effect of SMAW manufacturing process in high-cycle fatigue of AISI 304 base metal using AISI 308L filler metal

2015 ◽  
Vol 20 ◽  
pp. 181-189 ◽  
Author(s):  
M.F. Buchely ◽  
H.A. Colorado ◽  
H.E. Jaramillo
Keyword(s):  
Base Metal ◽  
Manufacturing Process ◽  
High Cycle Fatigue ◽  
Filler Metal ◽  
Cycle Fatigue ◽  
Aisi 304

Very High Cycle Fatigue Properties of Welded Joints under High Frequency Loading

2013 ◽  
Vol 647 ◽  
pp. 817-821
Author(s):  
Chao He ◽  
Yong Jie Liu ◽  
Qing Yuan Wang
Keyword(s):  
Base Metal ◽  
Welded Joints ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Ambient Air ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Very High

Very high cycle fatigue (VHCF) properties of welded joints under ultrasonic fatigue loading have been investigated for titanium alloy (TI-6Al-4V) and bridge steel (Q345). Ultrasonic fatigue tests of base metal and welded joints were carried out in ambient air at room temperature at a stress ratio R=-1. It was observed that the fatigue strength of welded joints reduced by 50-60% as compared to the base metal. The S-N fatigue curves in the range of 107~109 cycles of base metal and welded joints for both materials exhibited the characteristic of continually decreasing type. The fatigue failure still occurred after 107 cycles of loading, and the fatigue limit in traditional does not exist. The fatigue facture mainly located in the weld metal region at low cycle fatigue range, but in the fusion area in HCF and VHCF. Analysis of fracture surfaces analyzed by SEM revealed that the fatigue cracks initiated from welding defects such as pores, cracks and inclusions.

High Cycle Fatigue (HCF) Performance of Ti-6Al-4V Alloy Processed by Selective Laser Melting

2013 ◽  
Vol 816-817 ◽  
pp. 134-139 ◽  
Author(s):  
Eric Wycisk ◽  
Claus Emmelmann ◽  
Shafaqat Siddique ◽  
Frank Walther
Keyword(s):  
Fatigue Limit ◽  
Selective Laser Melting ◽  
Manufacturing Process ◽  
High Cycle Fatigue ◽  
Laser Energy ◽  
Critical Role ◽  
Base Material ◽  
Exploratory Research ◽  
Cycle Fatigue ◽  
Laser Melting

Selective laser melting (SLM) is a relatively new additive manufacturing (AM) technology which uses laser energy for manufacturing in a layered pattern. The unique manufacturing process of SLM offers a competitive advantage in case of very complex and highly customized parts having quasi-static mechanical properties comparable to those of wrought materials. However, it is not currently being harnessed in dynamic applications due to the lack of reliable fatigue data. The manufacturing process shows competitive advantages particularly in the aerospace and medical industry in which Ti-6Al-4V is commonly used, especially for high performance and dynamic applications. Therefore, in this exploratory research, high cycle fatigue (HCF) tests were performed for as-built, polished and shot-peened samples to investigate the capability of SLM for these applications. As-built samples showed a drastic decrement of fatigue limit due to poor surface quality (Ra ≈ 13 µm) obtained from the SLM process. Polishing improved the fatigue limit to more than 500 MPa, the typical value for base material. The effect of shot-peening proved to be antithetical to the expected results. In this context, fractographic analysis showed that very small remnant porosity (less than 0.4%) played a critical role in fatigue performance.

scholarly journals Failure mechanisms and fatigue strength reduction factor of a Cr-Ni-Mo-V steel welded joint up to ultra-long life regime

2018 ◽  
Vol 165 ◽  
pp. 21012 ◽  
Author(s):  
Ming-Liang Zhu ◽  
Fu-Zhen Xuan
Keyword(s):  
Fatigue Strength ◽  
Base Metal ◽  
High Cycle Fatigue ◽  
Welded Joint ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Cycle Fatigue ◽  
Strength Reduction Factor ◽  
Fatigue Design ◽  
Very High

It is known that welded joint is much “weaker” than base metal due to discontinuities of geometry, materials and residual stresses. It seems current international design rules do not adopt a uniform approach to weld efficiency, which is often defined as the ratio of the strength of a welded joint to the strength of base metal, in their guidance for creep and fatigue design of welds. This appears to be a great barrier for the application of nuclear welded structures which has a prolonged design lifetime of 60 years. In this work, fatigue strength reduction factor of a Cr-Ni-Mo-V steel welded joint, machined from welded steam turbine rotors for nuclear power plant, was investigated by performing axially push-pull cyclic loads tests with both cross-weld and pure base metal specimens up to very high cycle fatigue regime under ultrasonic frequency at ambient temperature. The effects of residual stress, strain localization, and microdefects in mismatched steels on failure mechanisms of welds were discussed thoroughly. Results show that fatigue strength reduction factor is varied in the range of 0.95-0.975, and is found to be dependent on fatigue lifetime for the first time. It is indicated that variation of fatigue strength reduction factor are associated with transition of crack initiation from specimen surface in high cycle fatigue regime to interior micro-defects in very high cycle fatigue regime. Comparing existing codes and standards for fatigue design of welds with experimental data indicates the over-conservativeness of present code-based design method. This implies a micro-defect based fatigue design approach is required for long life safe and reliability of weldments.

scholarly journals High-cycle Fatigue Properties of Alloy718 Base Metal and Electron Beam Welded Joint

2015 ◽  
Vol 67 ◽  
pp. 1028-1035 ◽  
Author(s):  
Yoshinori Ono ◽  
Tetsumi Yuri ◽  
Nobuo Nagashima ◽  
Hideshi Sumiyoshi ◽  
Toshio Ogata ◽  
...  
Keyword(s):  
Electron Beam ◽  
Base Metal ◽  
High Cycle Fatigue ◽  
Welded Joint ◽  
Fatigue Properties ◽  
Cycle Fatigue

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
Sign in / Sign up

Export Citation Format

Share Document