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Carbon		0.07 max
Chromium		15 - 17.5
Copper		3 - 5
Iron		Balance
Manganese		1 max
Nickel		3 - 5
Niobium		0.15 - 0.45
Niobium+Tantalum		0.15 - 0.45
Phosphorus		0.04 max
Silicon		1 max
Sulphur		0.03 max

Principal Design Features		One of the most widely used precipitation hardening grades in the business. While soft and ductile in the solution annealed condition, it is capable of high properties with a single precipitation or aging treatment. Characterized by good corrosion resistance, high harness, toughness and strength.

Applications		Commonly used in both aircraft and gas turbines, nuclear reactor, paper mill, oil field, and chemical process components.

Machinability		Long, gummy chips characterize this alloys machinability. It can be machined in the annealed condition, however condition H1150M will yield best results. Post machining solution treatment of parts will be required prior to final hardening if machining in this condition.

Forming		This alloy is capable of being only mildly formed. If forming is required, do so in the overaged condition for best results.

Welding		Successfully welded by common fusion and resistance methods, this alloy should not be joined by oxyacetylene welding. AWS E/ER630 filler metal is recommended if required.

Heat Treatment		CONDITION A--Soak at 1900 F (1038 C) for 30 minutes and cool below 60 F (16 C) for complete martensite transformation. CONDITION H 950- Treat Condition A material at 900 F(482 C) for 1 hour, air cool.. CONDITION H925, H1025, H1075, H1100, H1150- Soak solution treated material for 4 hours at specified temperature, air cool, CONDITION H1150M- Soak solution treated material at 1400 F (760 C) for 2 hours, air cool, then re-heat to 1150 F (620 C) for 4 hours and air cool.

Forging		Soak for 1 hour at 2150 F (1177 C) prior to forging. Do not work below 1850 F (1010 C). Post-work solution treatment is required prior to final hardening.

Hot Working		17-4 PH can be easily hot worked using most of the common processes. It is suggested that material be solution treated at 1900 F(1038 C) then formed during cooling while the material is still austenitic. Post-work solution treatment is required prior to final hardening.

Cold Working		Despite its high initial yield strength, 17-4 can be cold worked successfully by most common methods.

Annealing		1900 F (1038 C), hold for 1/2 hour, rapid cool.

Hardening		This alloy has good ductility and may be readily formed by all conventional methods. Because the alloy is stronger than regular steel it requires more powerful equipment to accomplish forming. Heavy-duty lubricants should be used during cold forming.

Physical Data : [top]

Density (lb / cu. in.)	0.28
Specific Gravity	7.74
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])	0.11
Electrical Resistivity (microhm-cm (at 68 Deg F))	588

MSO currently has no data available for this grade.