Description / Abstract:
This SAE Standard describes a new alphanumeric designation system for
wrought steel used to
designate wrought ferrous materials, identify chemical composition,
and any other requirements
listed in SAE Standards and Recommended Practices.
The previous SAE steel designation coding system consisted of four or
five numbers used to
designate standard carbon and alloy steels specified to chemical
composition ranges. Using SAE 1035
as an example, the 35 represents the nominal weight % carbon content
for the grade. Using SAE 52100
as an example, the 100 represents the nominal weight % carbon content.
The first two numbers of
this four or five number series are used to designate the steel grade
carbon or alloy system with
variations in elements other than carbon. These are described in Table
1. In addition to the
standard four or five number steel designation above, a letter was
sometimes added to the grade
code to denote a non-standard specific element being added to the
standard grade. For example, with
SAE 10B21, B designates a boron addition; with SAE 12L14, L designates
a lead addition; and with
SAE 10V45, V designates a vanadium addition.
For many years, the SAE four or five character steel designation
system has provided a simple way
to identify and label steel grades. However, it is not comprehensive
enough to allow for the
accurate coding of popular new or non-standard chemistry grades,
different chemistries for the same
grade that traditionally have been associated with a specific product
form, eg. SAE 1006 and SAE
1008, steel grades with dual chemistry and mechanical property
requirements, microalloyed grades,
and grades with both chemistry and hardenability requirements. As a
result, these grades could not
be properly recorded within the constraints of the previous steel
designation system and were not
included in the SAE steel grade Tables in SAE J403/J404 and other SAE
documents. The new steel
designation system is meant to ensure that the original or old SAE
steel grades are still usable
and both old and new SAE grades can be referenced uniformly between
Standards organizations. Since
the UNS numbering system for metals provides the basis for the
recording of steel grades between
North American and International Standards organizations, UNS was used
as the framework of the new
coding system. However, in order for the traditional five number UNS
code to be used, it had to be
expanded and modified to allow for an increase in the number of grades
that would need to be
classified in the future and to provide proper coding of new or
non-standard element modifications,
corresponding element ranges and dual hardenability, mechanical
property or special processing
requirements.
These new steel designations are the same in both the UNS and SAE
systems, as described in this
standard (J402) and the joint SAE J1086/ASTM E527 UNS Publication. An
alphanumeric code has been
developed to identify the composition of SAE steel grades.
Rationale
The name of J402 has been changed to reflect the "New SAE Steel
Designation System for Wrought or
Rolled Steel". SAE J402 has been completely rewritten to describe a
new SAE/UNS steel designation
system which will be used to identify current and new steel grades.
This system will replace the
old UNS designations used to identify modified SAE steel grades.