The fatigue strength of steel 18Kh2N4VA after different heat treatments and chemicothermal treatments

1971 ◽  
Vol 13 (3) ◽  
pp. 228-230
Author(s):  
B. I. Aleksandrov ◽  
E. G. Memelova
Keyword(s):  
Fatigue Strength ◽  
Heat Treatments ◽  
Steel 18Kh2n4va

scholarly journals The Effect of Heat Treatments on the Fatigue Strength of H13 Hot Work Tool Steel

2018 ◽  
Author(s):  
Ruhi Yeşildal
Keyword(s):  
Fatigue Strength ◽  
Heat Treatments ◽  
Fatigue Tests ◽  
Bending Test ◽  
Test Machine ◽  
Hot Work Steel ◽  
Tempering Treatment ◽  
Rotating Bending ◽  
And Behavior ◽  
Quenching And Tempering

The fatigue strength of the hot work steel depends on various factors, including the mechanical, properties and behavior and bulk and the surface under layer, the microstructural features as well as heat treatments. The influence of a series of heat treatments on the fatigue strength of H13 hot work steel was investigated. Different preheating, quenching and tempering treatments were applied to four sets of specimens and fatigue tests were conducted at room temperature using a rotating bending test machine. All heat treatments resulted in a certain improvement of the fatigue strength. Highest fatigue strength obtained by applying a double tempering heat treatment (first tempering at 550 °C for two hours and second tempering at 610 °C for two hours) after initial preheating and quenching. One tempering treatment (550 °C for two hours after preheating and quenching) did not significantly improve the fatigue strength.

scholarly journals The effect of post heat treatments on bending fatigue strength and wear characteristics of TiC coated steels.

1990 ◽  
Vol 2 (1) ◽  
pp. 13-16
Author(s):  
Munetoh Hashimoto ◽  
Masaki Shiratori ◽  
Shin-ici Nagashima ◽  
Syouhei Murayama ◽  
Kazuhiro Saito ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Heat Treatments ◽  
Bending Fatigue ◽  
Wear Characteristics ◽  
Bending Fatigue Strength

scholarly journals Low Pressure Carbonitriding of Steel Alloys with Boron and Niobium Additions

2019 ◽  
Author(s):  
Larissa Vilela Costa ◽  
Kip O. Findley ◽  
Vincent Lelong
Keyword(s):  
Heat Treatment ◽  
Fatigue Strength ◽  
Gear Tooth ◽  
Low Pressure ◽  
Heat Treatments ◽  
Steel Alloys ◽  
Bending Fatigue ◽  
Nb Microalloying ◽  
Nb Additions

Abstract Low pressure carbonitriding (LPCN) has the potential to improve impact and fatigue strength, with gears being an example application, through the enrichment of nitrogen in addition to carburizing at higher heat treatment temperatures. In this study, the LPCN response of four different steel alloys is investigated. The influence of unprotected boron is evaluated by comparing the LPCN response of 20MnCr5 with and without boron additions. The influence of Nb microalloying is assessed by comparing the LPCN response of 8620 with and without Nb additions. Low pressure carbonitriding heat treatments were developed to achieve case depths of 0.65 to 0.75 mm in each alloy. The hardness and case microstructure are correlated to bending fatigue response measured with Brugger fatigue specimens, which are designed to simulate the root of a gear tooth.

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

1985 ◽  
Vol 43 ◽  
pp. 190-191
Author(s):  
A. W. West
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Copper Matrix ◽  
Wire Drawing ◽  
Heat Treatments ◽  
Microstructural Development ◽  
Final Size ◽  
Density Values ◽  
The Wire ◽  
Multifilamentary Superconductors

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.

Microstructure Development in a High Current Density NbTi Superconducting Composite

1985 ◽  
Vol 43 ◽  
pp. 186-189
Author(s):  
P. J. Lee ◽  
D. C. Larbalestier
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Cold Drawing ◽  
Heat Treatments ◽  
Grain Structure ◽  
Fine Grain ◽  
Boundary Film ◽  
Quantitative Basis ◽  
Cold Worked ◽  
Very High

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.

Output Voltage Characteristics of Eddy Current Displacement Sensor for Various Heat Treatments of Measuring Objects

2008 ◽  
Vol 128 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Tsutomu Mizuno ◽  
Shigemi Enoki ◽  
Takashi Asahina ◽  
Takayuki Suzuki ◽  
Hiroyuki Maeda ◽  
...  
Keyword(s):  
Eddy Current ◽  
Output Voltage ◽  
Heat Treatments ◽  
Displacement Sensor
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