Stainless steel and heat resisting steels possess unusual resistance to attack by corrosive media at
atmospheric and elevated temperatures, and are produced to cover a wide range of mechanical and
physical properties for particular applications.
The commonly recognized standard types of stainless steel and heat resisting steels and several popular
special grades have widely differing characteristics and in many cases have special qualifications which
particularly recommend them for specific uses.
Stainless steel and heat resisting steels are usually melted by the electric furnace process. (Some stainless and heat resisting steels are produced also by vacuum processing).
The data which follows may be regarded as the basis for a majority of selection and working applications. In addition, the services of qualified Greenville Tube representatives are available not only
to assist the user in finalizing a proper materials selection, but to ensure his proper working of the metal
in production so as to avoid end-use problems.
It is characteristic of products made of stainless steel and heat resisting steels, in general, that they
require more than ordinary care throughout their fabrication. They are more sensitive to thermal and
mechanical operations, the control of which is complicated by the varying effects of different chemical
combinations. To secure the most satisfactory results purchasers of stainless steel tubing normally
consult with Greenville Tube regarding the working, machining, heat treating or other operations to be
employed in tubing fabrication; the mechanical properties to be obtained, and the conditions of service
for which the finished tubing articles are intended. Particular attention should be given to inform
Greenville Tube of the end use, if such information is available, and the details of operations to which
the steel will be subjected are known and can be transmitted for consultation.
Standard Types of Stainless Steel
Continuing studies on the part of the American Iron and Steel Institute have led to a simplified list of
steel compositions. The compilation is known as Standard Types. These were selected on the basis of
metallurgical judgment after consideration of many factors, including the advice and counsel of
engineering and specification writing bodies and the needs of the armed services. This method of
standardization has led to identification by types according to several groups, using a system of numbers
as follows.
System of Identification
In a three digit number, the first digit indicates the series or group and the last two digits indicate type.
Modifications of types are indicated by suffix letters. The series designations identify the following
groups.
| Designation |
Composition |
Description |
| 2xx |
Chromium
Nickel
Manganese
|
Non-hardenable, austenitic, and non-magnetic |
| 3xx |
Chromium
Nickel Steels
|
Non-hardenable, austenitic, and non-magnetic |
| 4xx |
Chromium Steels
|
Hardenable, ferritic, and magnetic |
| 5xx |
Chromium Steels |
Low chromium, heat-resisting |