This is a chromium-nickel grade of stainless steel that may be hardened by a single low-temperature precipitation-hardening heat treatment. Excellent mechanical properties at a high strength level may be obtained by such treatment. Scaling and distortion are minimized. This material should not be used in the solution treated condition.
The strength and corrosion resistance properties of 17-4 hold up well in service temperatures up to 800°F.
Fabrication techniques for this steel are similar to those established for the regular stainless steel grades. This material machines well, has excellent welding characteristics, and forges easily. The combination of excellent mechanical and processing properties makes this grade adaptable to a wide variety of applications.

AISI 630
UNS SI7400

Color Marking:
Bars—Ends painted Blue and Yellow
Plates—Corner striped Blue and Yellow

Stock Lengths 10' to 14'
Unit of Measure

Specifications

Estimated Weight per Foot

N/A .4786 lb

Estimated Weight 12-Ft. Bar

N/A 5.743 lb

Analysis

N/A Carbon .70 Max.
Manganese 1.00 Max.
Phosphorus .040 Max.
Sulphur .30 Max.
Si. 1.00 Max.
Cr.15.0/17.50
Ni. 3.00/5.00
Cu. 3.00/5.00
Cb. + Ta. 5x C/.45

Specifications

N/A AMS 5643 and ASTM A 564 Type 630 are generally applicable.

Applications

N/A Used where high strength and good corrosion resistance are required, as well as for applications requiring high fatigue strength, good resistance to galling, seizing and stress corrosion. Suitable for intricate parts requiring machining and welding, and/or where distortion in conventional heat treatment is a problem.

Corrosion Resistance

N/A The corrosion resistance of 17-4 is superior to that of hardenable straight chromium grades such as Type 410. It approaches the corrosion resistance of the chromium nickel grades. In many corrosive media it is equal to such grades as Type 302. Corrosion resisting properties will be affected bv such conditions as surface finish and aging heat treatment.

Machinability

N/A This grade has a machinability rating of 48% in the annealed condition (Condition A), with surface cutting speed of 80 feet per minute. In the overaged condition (H 1150-M), the machinability rating is 76%, with surface cutting speed of 125 feet per minute.

Weldability

N/A Readily-weldable by all the commercial processes. Preheating and post-heating practices used for the standard hardenable stainless grades are not required.

Forging

N/A Forge between 2050° and 2150°F. Do not forge below 18S0°F. Forgings are air cooled to 90°F or lower. Large or intricate forgings should be equalized at some temperature between 1900°F and the forging temperature before air-cooling.

Annealing

N/A The annealing (solution treatment) temperature is 1900°F, followed by air cooling. Maximum Brinell hardness at mid-radius is 363.

Hardening

N/A Condition H 900— 900°F for 1 hour, air cool. Rockwell "C" 44 Average.
Condition H 1025-1025°F for 4 hours, air cool. Rockwell "C" 38 Average.
Condition H 1150—1150°F for 4 hours, air cool. Rockwell "C" 33 Average.