Glide Stress by Stationary Creep of Tempered Martensite with Polyhedral Particles

2016 ◽  
Vol 88 (3) ◽  
pp. 1600200 ◽  
Author(s):  
Franc Vodopivec ◽  
Fevzi Kafexhiu ◽  
Borut Žužek ◽  
Bojan Podgornik
Keyword(s):  
Tempered Martensite ◽  
Polyhedral Particles ◽  
Stationary Creep

Calculation of stationary creep rate of tempered martensite

2013 ◽  
Vol 29 (4) ◽  
pp. 451-455 ◽  
Author(s):  
F Vodopivec ◽  
B Žužek ◽  
M Jenko ◽  
D A Skobir-Balantič ◽  
M Godec
Keyword(s):  
Creep Rate ◽  
Tempered Martensite ◽  
Stationary Creep

Cell structure properties during in situ creep experiments in the H.V.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 574-575
Author(s):  
D. Caillard ◽  
J.L. Martin
Keyword(s):  
Tensile Axis ◽  
Cell Structure ◽  
Image Intensifier ◽  
Foil Thickness ◽  
Average Cell Size ◽  
Average Cell ◽  
Voltage Electron ◽  
Steady Stage ◽  
Stationary Creep

The behaviour of the dislocation substructure during the steady stage regime of creep, as well as its contribution to the creep rate, are poorly known. In particular, the stability of the subboundaries has been questioned recently, on the basis of experimental observations |1||2| and theoretical estimates |1||3|. In situ deformation experiments in the high voltage electron microscope are well adapted to the direct observation of this behaviour. We report here recent results on dislocation and subboundary properties during stationary creep of an aluminium polycristal at 200°C.During a macroscopic creep test at 200°C, a cell substructure is developed with an average cell size of a few microns. Microsamples are cut out of these specimens |4| with the same tensile axis, and then further deformed in the microscope at the same temperature and stain rate. At 1 MeV, one or a few cells can be observed in the foil thickness |5|. Low electron fluxes and an image intensifier were used to reduce radiation damage effects.

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

CRUCIBLE 422

Alloy Digest ◽  
2007 ◽  
Vol 56 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Aerospace Industry ◽  
High Strength ◽  
Heat Treating ◽  
Tempered Martensite ◽  
Temperature Performance

Abstract Crucible 422 has a structure of tempered martensite to give the alloy high strength. It is useful in the aerospace industry for structurals with high strength/weight ratios. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1004. Producer or source: Crucible Service Centers.

DYNAMIC RECRYSTALLIZATION OF FERRITE IN A MEDIUM--CARBON STEEL WITH TEMPERED MARTENSITE STRUCTURE DURING HOT DEFORMATION

2010 ◽  
Vol 2010 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Longfei LI ◽  
Yangqing XIA ◽  
Zuqing SUN ◽  
Wangyue YANG
Keyword(s):  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Medium Carbon Steel ◽  
Tempered Martensite ◽  
Medium Carbon ◽  
Martensite Structure

INVESTIGATION OF THE TOUGHNESS OF LOW CARBON TEMPERED MARTENSITE IN THE SURFACE OF Ni--Cr--Mo--B ULTRA--HEAVY PLATE STEEL

2013 ◽  
Vol 48 (4) ◽  
pp. 401-406 ◽  
Author(s):  
Xiaoyong WANG ◽  
Tao PAN ◽  
Hua WANG ◽  
Hang SU ◽  
Xiangyang LI ◽  
...  
Keyword(s):  
Plate Steel ◽  
Low Carbon ◽  
Tempered Martensite ◽  
Heavy Plate

scholarly journals Toughness Property Control by Nb and Mo Additions in High-Strength Quenched and Tempered Boron Steels

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 95
Author(s):  
Irati Zurutuza ◽  
Nerea Isasti ◽  
Eric Detemple ◽  
Volker Schwinn ◽  
Hardy Mohrbacher ◽  
...  
Keyword(s):  
Solid Solution ◽  
Transition Temperature ◽  
High Strength ◽  
Unit Size ◽  
Tempered Martensite ◽  
Size Refinement ◽  
Direct Quenching ◽  
Property Control ◽  
The Impact ◽  
Impact Transition Temperature

The synergetic effect on hardenability by combining boron with other microalloying elements (such as Nb, Mo and Nb + Mo) is widely known for high-strength medium carbon steels produced by direct quenching and subsequent tempering treatment. The improvement of mechanical properties could be reached through optimization of different mechanisms, such as solid solution hardening, unit size refinement, strain hardening, fine precipitation hardening and the effect of carbon in solid solution. The current study proposes a procedure for evaluating the contribution of different microstructural aspects on Charpy impact toughness. First, the effect that austenite conditioning has on low-temperature transformation unit sizes and microstructural homogeneity was analysed for the different microalloying element combinations. A detailed crystallographic characterization of the tempered martensite was carried out using electron backscattered diffraction (EBSD) in order to quantify the effect of unit size refinement and dislocation density. The impact of heterogeneity and presence of carbides was also evaluated. The existing equations for impact transition temperature (ITT50%) predictions were extended from ferrite-pearlite and bainitic microstructures to tempered martensite microstructures. The results show that microstructural refinement is most beneficial to strength and toughness while unit size heterogeneity has a particularly negative effect on ductile-to-brittle transition behaviour. By properly balancing alloy concept and processing, steel having a yield strength above 900 MPa and low impact transition temperature could be obtained by direct quenching and tempering.

scholarly journals Prediction of Tempered Martensite Hardness Incorporating the Composition-Dependent Tempering Parameter in Low Alloy Steels

2014 ◽  
Vol 55 (7) ◽  
pp. 1069-1072 ◽  
Author(s):  
Singon Kang ◽  
Seok-Jae Lee
Keyword(s):  
Low Alloy Steels ◽  
Tempered Martensite ◽  
Alloy Steels

Cementite Precipitation of a H21 Tool Steel after Hot Compression and Double Temper

2014 ◽  
Vol 1043 ◽  
pp. 154-158
Author(s):  
Meilinda Nurbanasari ◽  
Panos Tsakiropoulos ◽  
Eric J. Palmiere
Keyword(s):  
High Temperature ◽  
Applied Stress ◽  
Tool Steel ◽  
Hot Deformation ◽  
Lower Bainite ◽  
Precipitation Behavior ◽  
Transformation Mechanism ◽  
Tempered Martensite ◽  
Bainite Transformation ◽  
Precipitation Behaviour

The cementite precipitation behavior in the martensite and banite of the H21 tool steel under high temperature axisymmetric compression test and double temper was investigated. The main purpose on this work is to develop a better understanding regarding the transformation mechanism of bainite and martensite in a H21 tool steel. The selected deformation temperatures were 1100 oC and 1000 oC and the double temper process was carried out at 650 oC for 1 hour respectively. The results showed that the cementite was sensitive to the stress. The applied stress has affected the Fe3C precipitation behaviour by decreasing the number of variants carbides in tempered martensite and decreasing the number of a single variant carbides in tempered lower bainite. The results were in agreement with a displacive mechanism of martensite and bainite transformation. It was also found that hot deformation temperatures selected in this work have the same contribution in decreasing number of variant carbides in tempered martensite and decreasing number of single variant carbides occurred in tempered lower bainite.

Sign in / Sign up

Export Citation Format

Share Document