Steel HY80

Aging Procedure

Not applicable to this alloy.

Annealing Procedure

A stress relief anneal may be done at 1200 F for 1 hour per inch of thickness, followed by furnace cooling at a rate not in excess of 200 F per hour down to 500 F. From there it can be air cooled.

Applications

This alloy is best known for use in shipbuilding for welded hull plates and structural use.

Cold Workability

HY-80 has very good ductility and is readily cold worked by conventional means. Bend radii of 2t for material up to one inch thick and 3t for material thickness' of one to two inches thick are recommended.

Forgeability

Because the alloy is supplied in the heat treated and tempered condition it should not be subsequently reheated for forging.

Formability

HY-80 may be readily cold or hot formed by conventional bending, or forming, processes. It does exhibit more springback than plain carbon steel so allowance must be made for that when bend forming.

Hardening Procedure

The alloy will harden by cold working. It is supplied in the hardened and tempered condition and should be used that way.

Heat Treatability

HY-80 is supplied in the quenched and tempered condition so a heat treatment as such is not required. It may be given a stress relief anneal, if deemed necessary, at 1200 F for one hour per inch of thickness followed by slow furnace cooling (not exceeding 200 F per hour) to 500 F, followed by air cooling.

Hot Workability

Hot working, if necessary, may be done in the range of 600 to 200 F.

Machinability

HY-80 steel is readily machined when in the quenched and tempered condition. It machines with the same feeds and speeds as for other low alloy steels with Rockwell C 20 hardness.

Other Mechanical Properties

HY-80 is noted for notch toughness. Charpy V-notch values are 50 ft lb. for material 1/2" to 1-1/2" thick and 30 ft lb. for over 1-1/2" thick.

Principle Design Features

HY-80 is a high yield strength (minimum of 80 ksi) , low carbon, low alloy steel with nickel, molybdenum and chromium. It has excellent weldability and notch toughness along with good ductility even in welded sections.

Tempering Procedure

HY-80 is supplied in the tempered condition of 80 ksi minimum yield strength. No additional tempering should be attempted.

Weldability

Weldments of HY-80 are noted for good ductility, notch toughness and strength. It is best welded using the metal-arc process with low hydrogen electrodes of Type E-10018 or E-11018. Use approved weld procedures so as to not apply too much heat input per inch of weld bead, which would otherwise cause degradation of notch toughness. Electrodes should be warmed before use to drive off any moisture to avoid hydrogen pick-up in the weld. Preheating is not required, except for very heavy section thickness welds or heavily constrained welds. Post-heating is not required but a stress relief anneal, after welding of sections of 1-1/2" thick or greater, is desirable. However the alloy may be used in the as-welded condition.