Introduction

Equivalent Material & Chemical Composition

Characteristics

* Good resistance to abrasion at both low and high temperatures

* High level of toughness and ductility

* Good machinability and polishability

* Good high-temperature strength and resistance to thermal fatigue

* Excellent through-hardening properties

* Very limited distortion during hardening

Applications

* PLASTIC MOULDING: Injection moulds, Compression/ transfer moulds;

* EXTRUSION: Backers, die holders, liners, dummy blocks, stems;

* DIE CASTING: Fixed inserts, cores, Sprue parts, Nozzles, Ejector pins (nitrided), Plunger;

* Others:  Forming dies, die inserts, and tools for the manufacture of screws nuts, riverts and bolts.

Physical Properties

H13 material physical properties such as density, specific heat capacity, and thermal properties, elastic modulus are given in the table below.

Mechanical Properties

Typical room-temperature longitudinal mechanical properties of H13 steel bars tempered to different hardness levels.

Round bars, oil quenched from 1010 °C (1850 °F) and double tempered, 2+2 hour at indicated temperature.

Longitudinal short-time tensile properties of H13 tool steel bar

Oil quenched from 1010 °C (1850 °F) and doubled tempered to indicated hardness.

Longitudinal impact properties of H13 tool steel bar tempered at different temperatures

Air cooled from 1010 °C (1850 °F) and double tempered, 2+2 hour at indicated temperature.

H13 Steel Hardness Range

H13 steel hardness range is 28-53 HRC varies with tempering temperature, all specimens are air-cooled from 1025 °C (1875 °F) and tempered at temperature for 2 hours.

Heat Treatment

Annealing

Heat uniformly to 845 to 900 °C (1550 to 1650 °F) in a controlled atmosphere furnace, or place the part in a neutral compound to prevent decarburization and hold to equalize temperature; Cool very slowly in the oven to approximately 480 °C (900 °F), then more rapidly to room temperature. This treatment should result in a fully spherical microstructure without grain boundary carbide networks.

Hardening

Preheat to 790 to 815 °C (1450 to 1500 °F), then continue heat uniformly to 995 to 1025 °C (1825 to 1875 °F), soak for 20 minutes, plus 5 minutes per 25 mm (1 in) thickness (min. 25 minutes); cool in still air. For a few applications, oil quenching can be done from the low end of the hardening temperature, but there is a risk of distortion or cracking. Air cooling is preferred and is usually done from the high side of the hardening temperature range.

Tempering

Temper at approximately 510 °C (950 °F) for maximum hardness and strength, but better tempered at higher temperatures to lower hardness or strength levels while increasing toughness and ductility.

Stress Relief

Heat to 650 to 675 °C (1200 to 1250 °F) and soak for 1 hour or longer; cool slowly to room temperature. This treatment is typically used to achieve greater dimensional accuracy in heat-treated parts by stress-relieving rough-machined parts, followed by finish machining, and finally heat-treating to the desired hardness.

Nitride

Finished and heat treated parts can be nitrided to produce a highly wear-resistant surface. Because it is carried out at normal tempering temperature, nitriding can serve as the second temper in a double-tempering treatment. The depth of the nitride layer depends on the time at temperature. Deeply nitrided parts are usually ground or lightly surface ground to remove the thin, brittle white layer. Selective nitridation is sometimes performed to produce a nitrided shell only where needed. Copper plating is best to seal off areas that do not require nitriding; stop-offs containing lead should be avoided as lead can make H13 steel brittle.

Normalizing

Not recommended