Carbide precipitation, grain boundary segregation, and temper embrittlement in NiCrMoV rotor steels

1985 ◽  
Vol 16 (5) ◽  
pp. 721-737 ◽  
Author(s):  
N. Bandyopadhyay ◽  
C. L. Briant ◽  
E. L. Hall
Keyword(s):  
Grain Boundary ◽  
Boundary Segregation ◽  
Temper Embrittlement ◽  
Carbide Precipitation ◽  
Grain Boundary Segregation

Study on the Hydrogen Effect on the Temper Embrittlement of 2.25Cr-1Mo Steel

2010 ◽  
Author(s):  
Xiliang Zhang ◽  
Changyu Zhou
Keyword(s):  
Hydrogen Embrittlement ◽  
Grain Boundary ◽  
Boundary Segregation ◽  
Temper Embrittlement ◽  
Grain Boundary Segregation ◽  
Hydrogen Effect ◽  
Electron Spectrometer ◽  
Boundary Concentration ◽  
Theory Calculation ◽  
The Relationship

The relationship between hydrogen embrittlement and temper embrittlement of 2.25Cr-1Mo steel was investigated by Auger electron spectrometer testing and electrochemical hydrogen charging. The results indicate that atomic hydrogen increases the grain boundary concentration of impurity element P and temper embrittlement. The increscent temper embrittlement degree by hydrogen will rise with further embrittlement and the relationship between increscent temper embrittlement degree and temper embrittlement degree is ΔCp = log[4.9351×(Cp)1.31687]. The grain boundary segregation theory was used and results of theory calculation and testing show that the relationship between hydrogen embrittlement and temper embrittlement can be explained by theory of grain boundary segregation. The embrittlement degree of 2.25Cr-1Mo steel which is induced by hydrogen and temper embrittlement is Cp′ = log[4.9351×(Cp)1.31687]+Cp.

Effect of Isothermal Holding Temperature on NGS Kinetics of Phosphorus and Temper Embrittlement

2007 ◽  
Vol 348-349 ◽  
pp. 549-552
Author(s):  
Jun Wang ◽  
Qing Fen Li ◽  
Er Bao Liu
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Isothermal Holding ◽  
Boundary Segregation ◽  
Temper Embrittlement ◽  
Solution Treatment ◽  
Grain Boundary Segregation ◽  
Solution Temperature ◽  
Kinetics Of ◽  
Holding Temperature

When failure occurs in material, it is often occurs by fracture along some grain boundaries and often by the micro-segregation of embrittling impurity to the grain boundaries. In the present work, the non-equilibrium grain-boundary segregation (NGS) kinetics of phosphorus and the temper embrittlement at the same solution treatment and different isothermal holding temperature in steel 2.25Cr1Mo are studied. The NGS kinetics curves of phosphorus at the same solution temperature （1050 oC ）and different isothermal holding temperature (540 oC and 600 oC) are given. Experimental results provide a direct evidence of NGS kinetic model and show that the grain boundary segregation concentrations of phosphorus for specimen isothermal holding at 540 oC are higher than those at 600 oC. The peak values of AES patterns of solute atoms for specimen isothermal holding at 540 oC are also higher than those at 600 oC. It is therefore concluded that the lower the isothermal holding temperature, the higher the segregation concentration of phosphorus at the grain-boundaries, and also the higher the degree of embrittlement.

Study on Temper Embrittlement of Phosphorus in Steel 12Cr1MoV

2005 ◽  
Vol 297-300 ◽  
pp. 1183-1188 ◽  
Author(s):  
Li Li ◽  
Qing Fen Li ◽  
Er Jun Guo ◽  
Er Bao Liu ◽  
Xin Fang Cui ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Isothermal Holding ◽  
Boundary Segregation ◽  
Temper Embrittlement ◽  
Critical Time ◽  
Charpy Impact ◽  
Grain Boundary Segregation ◽  
Solution Temperature ◽  
Segregation Process ◽  
Holding Temperature

According to the non-equilibrium grain-boundary segregation (NGS) kinetics curve of phosphorus, a series of Charpy impact tests was performed in an industrial steel 12Cr1MoV, at solution temperature 1050oC, with isothermal holding temperature 540oC, on specimens of different holding time (at the segregation process, the critical time, and the desegregation process respectively). The DBTT values were measured and a temper embrittlement kinetics curve was given. The reverse temper embrittlement NGS mechanism for steel 12Cr1MoV was proposed.

Grain boundary segregation and carbide precipitation in heat treated niobium superconducting radio frequency cavities

2021 ◽  
Vol 119 (19) ◽  
pp. 194102
Author(s):  
A. Dangwal Pandey ◽  
T. F. Keller ◽  
M. Wenskat ◽  
A. Jeromin ◽  
S. Kulkarni ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Radio Frequency ◽  
Boundary Segregation ◽  
Carbide Precipitation ◽  
Grain Boundary Segregation ◽  
Heat Treated ◽  
Superconducting Radio Frequency

Modelling of grain boundary segregation kinetics that are responsible on irreversible and reversible temper embrittlement of engineering steels

2004 ◽  
Vol 120 ◽  
pp. 69-77
Author(s):  
A. Kovalev ◽  
D. Wainstein
Keyword(s):  
Grain Boundary ◽  
Boundary Segregation ◽  
Temper Embrittlement ◽  
Auger Spectroscopy ◽  
Thermodynamic Activity ◽  
Grain Boundary Segregation ◽  
Carbon And Nitrogen ◽  
Reversible Temper ◽  
Main Factors ◽  
Adsorption Desorption

There are presented the computer models of multicomponent grain boundary segregation (GBS) that are formed at quenching or tempering of engineering steels. The modelling of these processes requires different algorithms. The dynamic model of segregation at quenching is based on solution of independent diffusion and adsorption-desorption equations for various impurities in steel tied by feedback. The model of segregation under tempering considers the influence of alloying and tempering parameters on concentration and thermodynamic activity of carbon in the α-solid solution. It is based on regression analysis of experimental data on grain boundaries chemical composition obtained by Auger spectroscopy. There is established that grain boundary enrichment by harmful impurities (S and P) is possible after carbon and nitrogen segregation dissolution. The models allow to analyze the competition of elements during formation of GBS and to establish main factors responsible on development of different kinds of embrittlement in engineering steels with various alloying and content of harmful impurities.

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