Jun 17 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Annealing
Hot Working
Hardening
Applications
Introduction
Stainless steel grade 317LM is a low-carbon, higher molybdenum austenitic stainless steel. It also has higher nickel content than stainless steel grade 317L. This alloy has been designed to resist corrosion due to sulfuric acid compounds. It possesses good corrosion resistance coupled with good mechanical properties and fabricability.
The following sections will discuss in detail about stainless steel grade 317LM.
Chemical Composition
The chemical composition of stainless steel grade 317LM is outlined in the following table.
|
Element |
Content (%) |
|
Chromium, Cr |
18-20 |
|
Nickel, Ni |
12-16 |
|
Molybdenum, Mo |
4-5 |
|
Manganese, Mn |
2 |
|
Silicon, Si |
1 |
|
Phosphorus, P |
0.045 |
|
Carbon, C |
0.03 |
|
Sulfur, S |
0.03 |
|
Iron, Fe |
Balance |
Physical Properties
The physical properties of stainless steel grade 317LM are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
7.7-8.03 g/cm3 |
0.278- 0.290 lb/in3 |
Mechanical Properties
The following table shows mechanical properties of stainless steel grade 317LM.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
515 MPa |
74 ksi |
|
Yield strength |
205 MPa |
30 ksi |
|
Modulus of elasticity |
190-210 GPa |
27557-30457 ksi |
|
Poisson’s ratio |
0.27-0.30 |
0.27-0.30 |
|
Elongation at break |
35% |
35% |
|
Hardness, (HRB) |
95 |
95 |
Other Designations
Other designations that are equivalent to stainless steel grade 317LM include the following.
|
ASTM A167 |
ASTM A213 |
ASTM A249 |
ASTM A312 |
ASTM A358 |
|
ASTM A182 |
ASTM A240 |
ASTM A269 |
ASTM A276 |
ASTM A376 |
|
ASTM A409 |
ASTM A479 |
|
|
|
Fabrication and Heat Treatment
Machinability
Stainless steel grade 317LM should be machined with low speeds and constant feeds to help reduce the tendency of this alloy to work harden. Grade 317LM is tougher than grade 317LM 304 and has long stringy chip. It is recommended that chip breakers should be used.
Forming
For forming stainless steel grade 317LM, twice the force is required. It is recommended that ample radii should be allowed during roll forming. As the material does not snap or break easily, it has to be cut through the entire thickness.
Welding
Welding of stainless steel grade 317LM can be performed using all the conventional methods. It is recommended that grade 317L or Inco 625 filler material should be used when required.
Annealing
Annealing of this material should be performed by soaking at 1121-1149°C (2050-2100°F), followed by water quenching.
Hot Working
Hot working of stainless steel grade 317LM is possible using all the conventional methods. The material should be heated to 1149-1260° C (2100-2300° F). it is advisable to not work this material below (927°C) 1700°F. To achieve optimum corrosion resistance, it is recommended that a post-work annealing process be carried out.
Hardening
Stainless steel grade 317LM can be hardened only through cold reduction.
Applications
Stainless steel grade 317LM is used in the following areas:
-
Paper pulp, textile, and food processing equipment
-
Flue gas scrubbers
-
Process equipment components for products such as dyestuffs, rubber, rayon, ink, chemicals, and bleaches.