17-4 stainless is an age-hardening martensitic stainless combining high strength with the corrosion resistance of stainless steel. Hardening is achieved by a short-time, simple low-temperature treatment. Unlike conventional martensitic stainless steels, such as type 410, 17-4 is quite weldable. The strength, corrosion resistance and simplified fabrication can make 17-4 stainless a cost-effective replacement for high strength carbon steels as well as other stainless grades.
At the solution treating temperature, 1900°F, the metal is austenitic but undergoes transformation to a low-carbon martensitic structure during cooling to room temperature. This transformation is not complete until the temperature drops to 90°F. Subsequent heating to temperatures of 900-1150°F for one to four hours precipitation strengthens the alloy. This hardening treatment also tempers the martensitic structure, increasing ductility and toughness.
Rolled Alloys stocks 17-4 in condition "A", and also stocks material in the hardened conditions H1150 and H1150D.
|MIN||3.0||15.0||-||-||3.0||-||-||5 x C||-||-||-|
AMS 5604, AMS 5643, AMS 5825
ASME SA 564, ASME SA 693, ASME SA 705, ASME Type 630
ASTM A 564, ASTM A 693, ASTM A 705, ASTM Type 630
NACE MR0175, S17400
W. Nr./EN 1.4548
17-4 Plate, 17-4 Round Bar, 17-4 Weld Wire
Common Trade Names17-4 Stainless
- High tensile strength and hardness to 600°F
- Corrosion resistant
- Excellent oxidation resistance to about 1100°F
- Creep-rupture strength to 900°F
- Gate valves
- Chemical processing equipment
- Pump shafts, gears, plungers
- Valve stems, balls, bushings, seats
Density: 0.282 lb/inch3
Melting Range: 2560 - 2625°F
Poisson's Ratio: 0.272
Electrical Resistivity: 463 Ohm-circ mil/ft
|Coefficient of Thermal Expansion, in/in°F x 10-6||-||7.2||7.5||7.8|
Btu • ft/ft2 • hr • °F
|Modulus of Elasticity,
psi X 106
Representative Tensile Properties, Longitudinal Direction
|Ultimate Tensile Strength, ksi||200||190||170||165||150||145||140||125|
|0.2% Yield Strength, ksi||185||175||165||150||135||125||120||85|
|Elongation % in 2" or 4XD||14||14||15||16||17||19||22||22|
|Reduction of Area, %||50||54||56||58||58||60||65||68|
|Hardness, Brinell (Rockwell)||420 (C 44)||409 (C42)||352 (C 38)||341 (C 36)||332 (C 35)||311 (C 33)||294 (C 31)||277 (C 27)|
|Impact Charpy V-Notch, ft - lbs||15||25||35||40||45||50||55||100|
|Condition A||Heated at 1900°F±25°F for 1/2 hour, air (Solution Treated) cooled or oil quenched to below 90°F. Normally performed at mill.
For most applications, 17-4 stainless should not be used in Condition A. This is true even though the desired tensile strength may be provided by that condition. The structure is untempered martensite that has low fracture toughness and ductility, while having poor resistance to stress-corrosion cracking. Superior service performance is assured by using 17-4 stainless in the heat-treated condition.
|H900||Condition A material heated at 900°F±15°F for 1 hour and air cooled. Maximum hardness but low toughness. Sensitive to stress corrosion cracking. Heating 4 hours improves toughness with about 4 ksi reduction in tensile and yield.|
|H925, H1025, H1075,
|Condition A material heated 4 hours at specific temperature, and air cooled.|
|H1150D||Condition A material heated 4 hours at 1150F, air cooled, heated again for an additional 4 hours at 1150F and air cooled.|
|H1150-M||Condition A material heated at 1400°F±25°F for 2 hours, air cooled, then heated at 1150°F±15°F for 4 hours and air cooled.|