17-4 STAINLESS STEEL– AMS 5643 – AISI 630 – UNS S17400
17-4 Stainless is a martensitic chromium-nickel-copper stainless steel in the solution treated (annealed) condition. It can be further hardened to various strength levels by a single precipitation hardening heat treatment that minimizes scaling and distortion. Its strength and moderate corrosion resistant properties are maintained in service temperatures up to the 600° F to 800° F range. The alloy should not be used in the solution treated (annealed) condition.
Bars, Wire, and Forgings are usually a single-melt product offered to AMS 5643 for aerospace applications. A CEVM (Consumable Electrode Vacuum Melt) or VAR (Vacuum Arc Remelt) product is specified in AMS 5622. Both specifications require that bars and forgings be restricted to 8” Diameter or less, or 8” least distance between parallel sides. A provision is included to allow larger sizes, provided that the Buyer and Seller agree upon mechanical properties for the size in question.
17-4 Stainless Applications:
17-4 Stainless is suitable for a wide variety of applications in the commercial, oil and gas, aerospace, and nuclear industries. It’s suitable for intricate parts requiring corrosion resistance and high strength that can be heat treated and welded with minimal distortion due to its precipitation hardening capabilities.
Common Trade Names:
|Cond A||0.280 #/in3|
|Cond H900||0.282 #/in3|
|Cond H1075||0.283 #/in3|
|Cond H1150||0.283 #/in3|
17-4 Stainless Corrosion Resistance:
17-4 Stainless exhibits superior corrosion resistance compared to hardenable 400-Series Stainless chromium grades such as Type 410 Stainless. It is nearly comparable that of 300-Series Stainless chromium nickel grades such as Type 304 Stainless. 17-4 corrosion resistance can be affected by surface finish and precipitation hardening heat treatment.
17-4 Stainless Fabrication:
This grade is readily forged, hot headed, or upset in the range 2050° F and 2200° F, and not below 1850° F. It is usually solution treated after hot work prior to precipitation hardening.
17-4 Stainless Machinability:
This material machines well in the Solution Treated (Annealed) condition, and about 50% better in Cond H1150.
17-4 Stainless Weldability:
It is readily weldable by commercial processes without being preheated or post-heated, as usually done for 400-Series Stainless grades.
17-4 Stainless AMS 5643 Hardness & Minimum Tensile Properties:
For diameters 8” and below (or least distance between parallel sides)
|Condition||Tensile||Yield 0.2% offset||Elongation (%in 2")||Reduction of Area||Brinell Hardness||Rockwell Hardness|
|H900||190 ksi||170 ksi||10%||40% (35% >3")||388-444 HB||40-47 HRC|
|H925||170 ksi||155 ksi||10%||44% (38% >3")||375-429 HB||38-45 HRC|
|H1025||155 ksi||145 ksi||12%||45%||331-401 HB||34-42 HRC|
|H1075||145 ksi||125 ksi||13%||45%||311-375 HB||31-38 HRC|
|H1100||140 ksi||115 ksi||14%||45%||302-363 HB||30-37 HRC|
|H1150||135 ksi||105 ksi||16%||50%||277-352 HB||28-37 HRC|
|Ann||-||-||-||-||363 max||39 HRC Max|
See AMS 5643 Section 220.127.116.11 for Tensile Test and Temperature requirements
17-4 Stainless is not used in the Solution Treated (Annealed) condition
|Symbol||Element||Min %||Max %||C||Carbon||-||0.07%||Mn||Manganese||-||1.00%||Si||Silicon||-||1.00%||P||Phosphorus||-||0.040%||S||Sulfur||-||0.030%||Cr||Chromium||15.00%||17.50%||Ni||Nickel||3.00%||5.00%||Cb (Nb)||Columbium (Niobium)||5 times Carbon %||0.45%||Cu||Copper||3.00%||5.00%||Mo||Molybdenum||-||0.50%|