Prev Page | Next Page

Pages: << 2 3 4 [5] 6 7

Critical Cooling Rate - Heat Treating

The rate of continuous cooling required to prevent undesirable transformation. For steel, it is the minimum rate at which austenite must be continuously cooled to suppress transformations above the Ms temperature.

 

Critical Strain

The strain just sufficient to cause recrystallization ; because the strain is small, usually only a few percent, recrystallization takes place from only a few nuclei, which produces a recrystallized structure consisting of very large grains.

 

Cyaniding

A case-hardening process in which a ferrous material is heated above the lower transformation range in a molten salt containing cyanide to cause simultaneous absorption of carbon and nitrogen at the surface and, by diffusion, create a concentration gradient. Quench hardening completes the process.

 

Cycle Annealing

An annealing process employing a predetermined and closely controlled time-temperature cycle to produce specific properties or microstructures.

 

Conditioning Heat Treatment

A preliminary heat treatment used to prepare a material for desired reaction to a subsequent heat treatment. For the term to be meaningful, the exact heat treatment must be specified.

 

Congruent Transformation

An isothermal or isobaric phase change in which both of the phases concerned have the same composition throughout the process.

 

Continuous Precipitation - Heat Treating

Precipitation from a supersaturated solid solution in which the precipitate particles grow by longrange diffusion without recrystallization of the matrix. Continuous precipitates grow from nuclei distributed more or less uniformly throughout the matrix. They usually are randomly oriented, but may form a Widmanstätten structure. Also called general precipitation. Compare with discontinuous precipitation , localized precipitation .

 

Continuous-Type Furnace

A furnace used for heat treating materials that progress continuously through the furnace, entering one door and being discharged from another. See belt furnace , direct-fired tunnel-type furnace , rotary retort furnace , shaker-hearth furnace .

 

Cooling Stresses

Residual stresses resulting from nonuniform distribution of temperature during cooling.

 

Case Hardening

A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The processes commonly used are carburizing and quench hardening; cyaniding; nitriding; and carbonitriding. The use of the applicable specific process name is preferred.

 

Prev Page | Next Page

Pages: << 2 3 4 [5] 6 7

Contribute Article
Spider Optimizer

© Copyright 2000 - 2017, by Engineers Edge, LLC www.engineersedge.com
All rights reserved
Disclaimer | Feedback | Advertising | Contact

List Your Company HERE!! Add SEO Directory Listing | Advertising Information