Description / Abstract:
This standard outlines the conditions that enhance the risk of
hydrogen embrittlement of steel and define the relief procedures
required to minimize the risk of hydrogen embrittlement. It is
intended to control the process.
Hydrogen embrittlement of steel, which can cause brittle
fractures under stress, occurs as a result of the absorption of
hydrogen during cleaning, phosphate coating and plating processes.
The susceptibility to hydrogen embrittlement increases with
increasing stress (internal or externally applied stress) and
increasing material strength.
Hardness readings in this specification are in Vickers scale.
SAE J417 should be referred to for conversion to other scales.
NOTE 1:
All references to temperatures relate to part core temperature
and not the indicated oven air temperature. Statistical data of
verifications in temperature at the center of the oven load and
oven temperature shall be established to develop the oven profile.
The temperature of parts in a batch type of baking furnace shall be
monitored with a thermocouple placed in the middle of the load. For
continuous bake ovens a temperature trace through the oven must be
run with a calibrated thermocouple in the lowest temperature
position, at least once a year.