M00006984
New product
GMW17346 1st Edition, September 2015 Induction Hardening and Tempering of Gray Iron Cylinder Bores
In stock
Warning: Last items in stock!
Availability date: 03/08/2022
Description / Abstract:
GMW17346, 1st Edition, September 2015 - Induction Hardening and Tempering of Gray Iron Cylinder Bores
This standard covers the requirements for induction hardening
and tempering heat treatment of the cylinder bores of gray iron
Duramax cylinder blocks. This standard only covers the
metallurgical (microstructure and hardness) requirements of the
Duramax block and the methods to verify.
Material Description. Induction hardening of
the cylinder bores in the DMax cylinder block is performed to
improve the wear-resistance in the piston-ring upper ring reversal
zone by selectively hardening only the region necessary to
accomplish improved wear resistance, see Figure 1. The choice of
induction hardening for this task was due to its flexibility in
heating only the precise area required and its very short cycle
time. Additionally, the martensitic transformation results in an
approximately 4.3% increase in specific volume, thus the pattern
was developed to minimize the impact on cylinder bore distortion.
Induction hardening of ferrous materials entails three basic steps;
heating to the austenitizing temperature; holding to fully convert
the structure to austenite; and rapidly cooling to convert the
austenite to martensite. In addition, many parts are subsequently
tempered to improve toughness.
Symbols. Not applicable.
Applicability. Response to induction hardening
is strongly influenced by initial process design parameters in
addition to the following variables: