Application of full-surface view in situ thermography measurements during ultrasonic fatigue of cast steel G42CrMo4

2015 ◽  
Vol 80 ◽  
pp. 459-467 ◽  
Author(s):  
Dominik Krewerth ◽  
Tim Lippmann ◽  
Anja Weidner ◽  
Horst Biermann
Keyword(s):  
Cast Steel ◽  
Surface View ◽  
Ultrasonic Fatigue

A Comparative Study on Infrared Thermography during Ultrasonic Fatigue Testing of Cast Steel 42CrMo4 and Cast Aluminium Alloy AlSi7Mg

2013 ◽  
Vol 592-593 ◽  
pp. 501-504 ◽  
Author(s):  
Dominik Krewerth ◽  
Anja Weidner ◽  
Horst Biermann
Keyword(s):  
Aluminium Alloy ◽  
Infrared Thermography ◽  
Fatigue Testing ◽  
Cast Steel ◽  
Material Testing ◽  
Initiation Point ◽  
Testing Method ◽  
Cast Aluminium ◽  
Ultrasonic Fatigue ◽  
Non Destructive

The present paper illustrates a comparison of infrared thermography during ultrasonic fatigue testing of cast steel 42CrMo4 and cast aluminium alloy AlSi7Mg. Against the background of different material properties (e.g. mechanical properties as well as thermal properties) the benefit of this non-destructive material testing method in terms of determining the crack initiation point and time during fatigue testing as well as crack propagation is evaluated and discussed. Moreover, correlations between fractography and infrared thermography are performed for both materials.

scholarly journals In situ synchrotron ultrasonic fatigue testing device for 3D characterisation of internal crack initiation and growth

2019 ◽  
Vol 43 (3) ◽  
pp. 558-567 ◽  
Author(s):  
Alexandre Messager ◽  
Arnaud Junet ◽  
Thierry Palin‐Luc ◽  
Jean‐Yves Buffiere ◽  
Nicolas Saintier ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Fatigue Testing ◽  
Internal Crack ◽  
Testing Device ◽  
Ultrasonic Fatigue

Development of a photomicroscope method for in situ damage monitoring under ultrasonic fatigue test

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kai Tan ◽  
Victor Postel ◽  
Yujia Liu ◽  
Dongtong Yang ◽  
Sen Tang ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Early Stage ◽  
Strain Analysis ◽  
Infrared Camera ◽  
Small Crack ◽  
Image Correlation ◽  
Content Type ◽  
Damage Monitoring ◽  
Ultrasonic Fatigue

PurposeMechanical issues related to the information and growth of small cracks are considered to play a major role in very high cycle fatigue (VHCF) for metallic materials. Further efforts on better understanding in early stage of a crack are beneficial to estimating and preventing catastrophic damage for a long period service.Design/methodology/approachDependent on the ultrasonic loading system, a novel method of in situ photomicroscope is established to study the crack behaviors in VHCF regime.FindingsThis in situ photomicroscope method provides advantages in combination with fatigue damage monitoring at high magnification, a large number of cycles, and efficiency. Visional investigation with attached image proceeding code proves that the method has high resolution on both size and time, which permits reliable accuracy on small crack growth rate. It is observed that the crack propagation trends slower in the overall small crack stage down to the level of 10–11 m/cycle. Strain analysis relays on a real-time recording which is applied by using digital image correlation. Infrared camera recording indicates the method is also suitable for thermodynamic study while growth of damage.Originality/valueBenefiting from this method, it is more convenient and efficient to study the short crack propagation in VHCF regime.

scholarly journals Simultaneously Enhanced Strength, Toughness and Ductility of Cast 40Cr Steels Strengthened by Trace Biphase TiCx-TiB2 Nanoparticles

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 707 ◽  
Author(s):  
Chuan-Lu Li ◽  
Feng Qiu ◽  
Fang Chang ◽  
Xu-Min Zhao ◽  
Run Geng ◽  
...  
Keyword(s):  
Cast Steel ◽  
Casting Process ◽  
Difficult Problem ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Pinning Effect ◽  
Cast Steels ◽  
Bainite Structure ◽  
Fine Microstructure

Simultaneously improving the strength, toughness, and ductility of cast steels has always been a difficult problem for researchers. Biphase TiCx-TiB2 nanoparticle-reinforced cast steels are prepared by adding in situ nanosized biphase TiCx-TiB2/Al master alloy during the casting process. The experimental results show that a series of significant changes take place in the microstructure of the steel: the ferrite-pearlite structure of the as-cast steels and the bainite structure of the steels after heat treatment are refined, the grain size is reduced, and the content of nanoparticles is increased. Promotion of nucleation and inhibition of dendrite growth by biphase TiCx-TiB2 nanoparticles leads to a refinement of the microstructure. The fine microstructure with evenly dispersed nanoparticles offers better properties [yield strength (1246 MPa), tensile strength (1469 MPa), fracture strain (9.4%), impact toughness (20.3 J/cm2) and hardness (41 HRC)] for the steel with 0.018 wt.% biphase TiCx-TiB2 nanoparticles, which are increased by 15.4%, 31.2%, 4.4%, 11.5%, and 7.9% compared with the 40Cr steels. The higher content of nanoparticles provides higher strengths and hardness of the steel but are detrimental to ductility. The improved properties may be attributed to fine grain strengthening and the pinning effect of nanosized carbide on dislocations and grain boundaries. Through this work, it is known that the method of adding trace (0.018 wt.%) biphase TiCx-TiB2 nanoparticles during casting process can simultaneously improve the strength, toughness, as well as ductility of the cast steel.

In-Situ Corrosion Studies on Cast Steel for a High-Level Waste Packaging in a Rock Salt Repository

1988 ◽  
Vol 127 ◽  
Author(s):  
W. Schwarzkopf ◽  
E. Smailos ◽  
R. Koster
Keyword(s):  
Electron Beam ◽  
Rock Salt ◽  
Corrosion Behaviour ◽  
Cast Steel ◽  
Maximum Temperature ◽  
High Level Waste ◽  
General Corrosion ◽  
Vertical Temperature Profile ◽  
Corrosion Studies

ABSTRACTPrevious corrosion studies performed on a number of materials have shown that unalloyed steels are promising materials for long-term resistant packagings to be used in disposal of heat-generating wastes in rock salt formations. This is the reason why those steels are the subject of more detailed investigations. This paper reports an in-situ experiment conducted in the Asse salt mine in which the influence of selected characteristics (welding, shape) of containers on the corrosion behaviour of cast steel was studied. The material was tested in NaCl brine which might intrude into an HLW borehole in an accident scenario. For this, an electron beam welded cast-steel tube was stored for 18 months in a 2-m deep heated borehole and the annular gap between the tube and the borehole wall was filled with saturated NaCl brine. The vertical temperature profile in the borehole was in the range from 90°C to 200°C; the maximum temperature occurred in the center of the heated zone and the minimum temperature in the upper parts of tube.Under the testing conditions cast steel was subjected to general corrosion at a maximum corrosion rate of 120 μm/a. Considering this magnitude of the corrosion rates, the resulting corrosion allowances are technically acceptable for a packaging having long service-lives. Pitting and crevice corrosion as well as stress-corrosion cracking did not occur in cast steel, and electron beam welding did not exert a noticeable influence on cast-steel corrosion. With these results available, cast steel continues to be considered as a promising HLW packaging material.

In Situ Imaging of High Cycle Fatigue Crack Growth in Single Crystal Nickel-Base Superalloys by Synchrotron X-Radiation

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Liu Liu ◽  
Naji S. Husseini ◽  
Christopher J. Torbet ◽  
Divine P. Kumah ◽  
Roy Clarke ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Single Crystal ◽  
Real Time ◽  
Crack Growth ◽  
Fatigue Cracks ◽  
X Ray ◽  
Ultrasonic Fatigue ◽  
Nickel Base Superalloys ◽  
Nickel Base

A novel X-ray synchrotron radiation approach is described for real-time imaging of the initiation and growth of fatigue cracks during ultrasonic fatigue (f=20kHz). We report here on new insights on single crystal nickel-base superalloys gained with this approach. A portable ultrasonic fatigue instrument has been designed that can be installed at a high-brilliance X-ray beamline. With a load line and fatigue specimen configuration, this instrument produces stable fatigue crack propagation for specimens as thin as 150μm. The in situ cyclic loading/imaging system has been used initially to image real-time crystallographic fatigue and crack growth under positive mean axial stress in the turbine blade alloy CMSX-4.

Composite Zones Obtained by in situ Synthesis in Steel Castings

2013 ◽  
Vol 58 (3) ◽  
pp. 769-773 ◽  
Author(s):  
E. Olejnik ◽  
S. Sobula ◽  
T. Tokarski ◽  
G. Sikora
Keyword(s):  
Base Alloy ◽  
Cast Steel ◽  
Low Carbon ◽  
Transition Area ◽  
Steel Castings ◽  
Characteristic Features ◽  
Two Phases ◽  
Transition Areas ◽  
Hardness Values

Abstract Application of in-situ technique allows for fabrication of composite zone in the casting with a matrix of cast steel with low carbon content. The reinforcing phase in the composite zone is titanium carbide, produced by the synthesis of substrates introduced into the mould in the form of pressed compacts. Metallographic studies were performed in order to determine of homogeneity of composite zones and characteristic features existed in transition area between the composite zone and core of the casting. The transition areas of composites zone were blurred and there were no discontinuities caused by poor bonding between the composite zone and the core of the casting. To confirm the correct run of the TiC synthesis, phase analysis was performed of the base alloy as well as composite zone. The results of this examination indicated that there were two phases in composite zone, i.e. α Fe and TiC and only α Fe was observed in base alloy. Changes of mechanical properties in the composite zone were examined, measuring its hardness HV. The average hardness values of the base alloy and composite zone were 175 ±4 and 696 ±201 HV, respectively.

In-Situ Corrosion Studies on Cast Steel High-Level Waste Containers Plated with Titanium/Nickel-Alloys

1991 ◽  
Vol 257 ◽  
Author(s):  
W. Schwarzkopf ◽  
E. Smailos ◽  
R. KÖster
Keyword(s):  
Corrosion Protection ◽  
Corrosion Behaviour ◽  
Cast Steel ◽  
Steel Tube ◽  
High Level Waste ◽  
Vertical Temperature Profile ◽  
Corrosion Studies ◽  
In Situ Experiments ◽  
Container Manufacturing

ABSTRACTPrevious corrosion studies have shown that the passive alloys Ti 99.8-Pd and Hastelloy C4 are the most promising corrosion protection materials for long-term resistant carbon-steel containers for the disposal of heat-generating wastes in rock salt formations. Consequently, these materials are subject to more detailed investigations. The influence of selected container manufacturing characteristics (sealing technique, application mode of the corrosion protecting layer on the steel) on the corrosion behaviour of Ti 99.8-Pd and Hastelloy C4was studied using in-situ experiments. The corrosion resistance of the materials was examined both in NaCI brine and MgCl2-rich brine, which might enter into an HLW borehole under certain disposal conditions. Four electron-beam welded cast-steel tubes plated with corrosion protection layers made of Ti 99.8-Pd and Hastelloy C4, respectively, were stored for 18 months in 2-m deep heated boreholes in the Asse salt mine. The annular gap between the tubes and the borehole wall was filled with saturated NaCl-brine or Qbrine (MgCl2-rich). The vertical temperature profile in the boreholes ranged from 90°C to 200°CIn the cast-steel tube with a corrosion protection of Ti 99.8-Pd, no indication of corrosion was observed on the EB-welds or on the explosion plated material in both brines. The cast-steel tube with a corrosion protection of Hastelloy C4 also was found to be resistant to any kind of corrosion in the NaCl-brine. In the MgCl2-rich brine, however, small pitting corrosion of 15 pm was observed after 1.5 years on the passive surface layer that was formed.On the basis of these results, Ti 99.8-Pd continues to be considered as a promising corrosion protection material for long-lived HLW containers.

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