Precipitation characteristics during isothermal γ to α transformation and resultant hardness in low carbon vanadium–titanium bearing steel

2015 ◽  
Vol 32 (1) ◽  
pp. 15-21 ◽  
Author(s):  
J. Chen ◽  
M. Y. Lv ◽  
S. Tang ◽  
Z. Y. Liu ◽  
G. D. Wang
Keyword(s):  
Bearing Steel ◽  
Low Carbon ◽  
Precipitation Characteristics ◽  
Vanadium Titanium

Aluminum nitride buffer layer for diamond film growth

1996 ◽  
Vol 11 (7) ◽  
pp. 1810-1818 ◽  
Author(s):  
V. P. Godbole ◽  
J. Narayan
Keyword(s):  
Aluminum Nitride ◽  
Buffer Layer ◽  
Diamond Film ◽  
High Speed ◽  
Film Growth ◽  
High Speed Steel ◽  
Bearing Steel ◽  
Low Carbon ◽  
Wide Range ◽  
Steel Substrates

The role of aluminum nitride (AlN) as a buffer layer on the nucleation and growth of diamond on silicon and steel substrates during hot filament chemical vapor deposition (HF-CVD) has been investigated systematically. The scanning Auger electron microscopy (AES) is employed to study chemistry and content of carbon on the surface and in subsurface regions of AlN as a function of HF-CVD parameters. It is found that AlN offers an excellent diffusion barrier for carbon over a wide range of temperature and hydrocarbon content of CVD gas environment, with simultaneous inhibition of graphitization. It also facilitates nucleation of diamond phase. The surface reactions between AlN and carbon are discussed in terms of hydrogen-assisted phase transformations. We have developed a two-step procedure to obtain a continuous diamond film on steel substrates. The characteristic features of AlN have been exploited to obtain adherent and graphite-free diamond deposits on various types of steels, including low carbon steel, tool steel, high speed steel, and bearing steel.

Development of high strength hot rolled low carbon copper-bearing steel containing nanometer sized carbides

2015 ◽  
Vol 633 ◽  
pp. 1-8 ◽  
Author(s):  
M.P. Phaniraj ◽  
Young-Min Shin ◽  
Joonho Lee ◽  
Nam Hoon Goo ◽  
Dong-Ik Kim ◽  
...  
Keyword(s):  
High Strength ◽  
Bearing Steel ◽  
Low Carbon ◽  
Hot Rolled

Effects of Microstructure Transformation on Strengthening and Toughening for Heat-Treated Low Carbon Martensite Stainless Bearing Steel

2015 ◽  
Vol 817 ◽  
pp. 667-674 ◽  
Author(s):  
Xiao Hong Yuan ◽  
Mao Sheng Yang ◽  
Kun Yu Zhao
Keyword(s):  
Electron Microscope ◽  
Cryogenic Treatment ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Bearing Steel ◽  
Strength Increase ◽  
Low Carbon ◽  
Packet Size ◽  
Block Width ◽  
Carbon Martensite

Microstructural transformations and mechanical properties of a low carbon martensite stainless bearing steel treated with different heat treatment parameters and cryogenic treatment (-82°C) were investigated. The function of microstructural transformations on strengthening and toughening process was quantitatively characterized as well. These analyses were performed by the optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and electron back scattering diffraction (EBSD) technique. The obtained results show that with execution of cryogenic treatment and tempering, the tensile strength increase owing to the reduction of retained austenite and fine carbides precipitating respectively. The effect of martensitic microstructure on yield strength increment can be regarded as packet size and block width which conform to Hall-Petch relationship. Meanwhile, the results suggest that the block width is the key structural controlling unit when analyzing the strength-structure relationship of lath martensite in low carbon martensite stainless bearing steel. In addition, packet size can be related to toughness controlling as well because of the same size as cleavage plane.

scholarly journals Interaction between Microalloying Additions and Phase Transformation during Intercritical Deformation in Low Carbon Steels

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1049 ◽  
Author(s):  
Unai Mayo ◽  
Nerea Isasti ◽  
Jose M. Rodriguez-Ibabe ◽  
Pello Uranga
Keyword(s):  
Rolling Process ◽  
Bearing Steel ◽  
Phase Region ◽  
Carbon Steels ◽  
Transformation Model ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Electron Backscattered Diffraction ◽  
Two Phase ◽  
Line Pipe

Heavy gauge line pipe and structural steel plate materials are often rolled in the two-phase region for strength reasons. However, strength and toughness show opposite trends, and the exact effect of each rolling process parameter remains unclear. Even though intercritical rolling has been widely studied, the specific mechanisms that act when different microalloying elements are added remain unclear. To investigate this further, laboratory thermomechanical simulations reproducing intercritical rolling conditions were performed in plain low carbon and NbV-microalloyed steels. Based on a previously developed procedure using electron backscattered diffraction (EBSD), the discretization between intercritically deformed ferrite and new ferrite grains formed after deformation was extended to microalloyed steels. The austenite conditioning before intercritical deformation in the Nb-bearing steel affects the balance of final precipitates by modifying the size distributions and origin of the Nb (C, N). This fact could modify the substructure in the intercritically deformed grains. A simple transformation model is proposed to predict average grain sizes under intercritical deformation conditions.

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