ASTM B874-96(2013) - 1.12.2013
 
1. Scope

1.1 This specification covers the requirements for chromium diffusion of metals by the pack cementation method. Pack diffusion employs the chemical vapor deposition of a metal which is subsequently diffused into the surface of a substrate at high temperature. The material to be coated (substrate) is immersed or suspended in a powder containing chromium (source), a halide salt (activator), and an inert diluent such as alumina (filler). When the mixture is heated, the activator reacts to produce an atmosphere of chromium halides which transfers chromium to the substrate for subsequent diffusion. The chromium-rich surface enhances corrosion, thermal stability, and wear-resistant properties.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

C664-24

Standard Test Methods for Thickness of Diffusion Coating

B762-21

Standard Guide of Variables Sampling of Metallic and Inorganic Coatings

B697-88(2021)

Standard Guide for Selection of Sampling Plans for Inspection of Electrodeposited Metallic and Inorganic Coatings

B602-21

Standard Guide for Attribute Sampling of Metallic and Inorganic Coatings

E766-14(2019)

Standard Practice for Calibrating the Magnification of a Scanning Electron Microscope

E1077-14(2021)

Standard Test Methods for Estimating the Depth of Decarburization of Steel Specimens

B374-24

Standard Terminology Relating to Electroplating

B487-24

Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section

D3951-18(2023)

Standard Practice for Commercial Packaging

F1330-91(2023)

Standard Guide for Metallic Abrasive Blasting to Descale the Interior of Pipe