SCOPE
This information sheet recommends powder metallurgy, PM, steel materials and metallurgical quality characteristics for use in specifying PM gearing. It identifies specifications and requirements for various PM steel materials for as-sintered, through hardened or sinter hardened, carburized case hardened, and induction hardened gearing. Characteristics covered include material composition, density, sinter processing (conventional, high temperature and sinter hardening), secondary heat treatments and post heat treatment processing, and their associated inspections. Topics related to gear design and rating such as case depth, stress (bending fatigue and contact fatigue capacity) and quality control systems are not included.

FOREWORD
[The foreword, footnotes and annexes, if any, in this document are provided for informational purposes only and are not to be construed as a part of AGMA Information Sheet, 942-A12, Metallurgical Specifications for Powder Metallurgy, PM, Steel Gearing.]

This document provides the critical metallurgical characteristics of powder metallurgy, PM, gears that will ensure the metallurgical quality of the teeth. The format of the document has been modeled on AGMA 923-B05, Metallurgical Specifications for Steel Gearing, and may be considered a companion document for gear designers seeking the same type of metallurgical features in PM steel gears as found in wrought gears. By using AGMA 923-B05 as a guide the gear designer can easily evaluate a PM material-process system based on the familiar features of wrought steel gears.

This information sheet is dedicated to Howard Sanderow. His participation and inspiration led to the development of this information sheet. His thoroughness and enthusiasm for the powder metallurgy industry, along with his contributions, as well as the contributions of his fellow committee members brought out the best from the committee as a whole.

The first draft of AGMA 942-A12 was made in May, 2007. It was approved by the AGMA membership in August 16, 2012.

NORMATIVE REFERENCES
The following documents contain provisions which, through reference in this text, constitute provisions of this information sheet.  At the time of publication, the editions were valid. All publications are subject to revision, and the users of this information sheet are encouraged to investigate the possibility of applying the most recent editions of the publications listed.

Gear related specifications
AGMA 923-B05, Metallurgical Specifications for Steel Gearing
AGMA 938-A05, Shot Peening of Gears

Steel related specifications
ASTM A751-11, Standard Test Methods, Practices and Terminology for Chemical Analysis of Steel Products
ASTM E3-11, Standard Guide for Preparation of Metallographic Specimens
ASTM E18-11, Standard Test Methods for Rockwell Hardness of Metallic Materials
ASTM E92-04, Standard Test Method for Vickers Hardness of Metallic Materials
ASTM E384-11, Standard Test Method for Knoop and Vickers Hardness of Materials
ASTM E407-07, Standard Practice for Microetching Metals and Alloys
ASTM E415-08, Standard Test Method for Atomic Emission Vacuum Spectrometric Analysis of Carbon and LowSteel
ASTM E1019-11, Standard Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques
ASTM E1077-01, Standard Test Method for Estimating the Depth of Decarburization of Steel Specimens
ASTM E1184-10, Standard Practice for Determination of Elements by Graphite Furnace Atomic Absorption Spectrometry

Powder metallurgy related specifications
ASTM B243-11, Standard Terminology of Powder Metallurgy
ASTM B783-10, Standard Specification for Materials for Ferrous Powder Metallurgy (P/M) Structural Parts
ASTM B797-93, Standard Test Method for Surface Finger Oxide Penetration Depth and Presence of Inter-particle Oxide Networks in Powder Forged (P/F) Steel Parts
ASTM B933-09, Standard Test Method for Microindentation Hardness of Powder Metallurgy (PM) Materials
ISO 3252:1999, Powder metallurgy –Vocabulary
ISO 4498:2010, Sintered metal materials, excluding hardmetals –Determination of apparent hardness and microhardness
MPIF Std 09(99), Definition of Terms Used in Powder Metallurgy
MPIF Std 10(00), Determination of Tensile Properties of Powder Metallurgy Materials
MPIF Std 35(09), Material Standards for P/M Structural Parts
MPIF Std 40(00), Determination of Impact Energy of Unnotched Powder Metallurgy Test Specimens
MPIF Std 42(04), Determination of Density of Compacted or Sintered Powder Metallurgy Products
MPIF Std 43(05), Determination of Apparent Hardness of Powder Metallurgy Products
MPIF Std 51(05), Determination of Microindentation Hardness of Powder Metallurgy Materials
MPIF Std 52(05), Determination of Effective Case Depth of Ferrous Powder Metallurgy Products
MPIF Std 56(01), Determination of Rotating Beam Fatigue Endurance Limit in Powder Metallurgy Materials

Reaffirmed August 2022.

ISBN: 978-1-61481-031-5

Pages: 17