Jun 21 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Heat Treatment
Welding
Annealing
Forging
Hot Working
Cold Working
Hardening
Applications
Introduction
Stainless steel grade 19-9 DL is a solid solution strengthened austenitic stainless steel.
This alloy is noted for its fine grain quality and stability in a wide range of temperatures. It provides good resistance to not only corrosion but also brittle failure.
The characteristics of this material are quite similar to that of stainless steel grade 316.
The following sections will discuss in detail about stainless steel grade 19-9 DL.
Chemical Composition
The chemical composition of stainless steel grade 19-9 DL is outlined in the following table.
|
Element |
Content (%) |
|
Chromium, Cr |
18 - 20 |
|
Nickel, Ni |
8-11 |
|
Manganese, Mn |
1.5 - 0.75 |
|
Molybdenum, Mo |
1 - 1.75 |
|
Tungsten |
1 - 1.75 |
|
Silicon, Si |
0.3 - 0.8 |
|
Carbon, C |
0.28 - 0.55 |
|
Niobium (Nb) + Tantalum (Ta) |
0.25 - 0.6 |
|
Titanium, Ti |
0.5 max |
|
Iron, Fe |
Balance |
Physical Properties
The physical properties of stainless steel grade 19-9 DL are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
8.02 g/cm3 |
0.29 lb/in3 |
Other Designations
Other designations that are equivalent to stainless steel grade 19-9 DL include the following.
|
ASTM A477 (651) |
ASTM A458 (651) |
ASTM A457 (651) |
ASTM A453 (651) |
AMS 5579 |
|
AMS 5526 |
AISI 651 |
|
|
|
Fabrication and Heat Treatment
Machinability
For machining stainless steel grade 19-9 DL, slow speeds, constant feeds, and good quantity of sulfurized lubricants are required for optimum results. Tough, "gummy" chips are produced during machining which can be dealt with using chip breakers or curlers.
Heat Treatment
Being an austenitic steel, stainless steel grade 19-9 DL does not respond to heat treatment.
Welding
Stainless steel grade 19-9 DL can be easily welded using all the conventional methods. Filler metal should be of matching chemistry so as to optimize performance whenever necessary.
Annealing
Annealing can be performed by soaking at 982-1177°C (1800-2150°F), and then air cooled. For stress relieving, the material should be heated to 649°C (1200°F), and then held for 60 min and air cooled.
Forging
For forging this material, it has to be soaked completely at 1177°C (2150°F) and then air cooled. Given sufficient hammer strength, this material can be forged down to 677°C (1250°F).
Hot Working
This material can be easily forged, headed and upset.
Cold Working
This alloy can be successfully cold worked using most of the common methods. In case of severe working, the material should be stress relief annealed without delay after forming at 649-704°C (1200-1300° F).
Hardening
Stainless steel grade 19-9 DL does not respond to hardening by thermal treatment.
Applications
Stainless steel grade 19-9 DL employed in applications where resistance to intergranular corrosion is not a big concern.
It is also used in numerous jet engine components such as manifolds, casings, buckets and fasteners.