H13 1.2344 SKD61 Hot Forged Mould Steel Bar

Introduce 

H13 steel is the most popular and most versatile, hot work mould steel, providing a good balance of toughness, heat check resistance, and high temperature strength, in addition to moderate wear resistance. H13 steel can resist softening to 550°C and has good resistance to heat checking. Will Nitride with a case hardness over 1000 V.P.N. Generally supplied annealed to HB 230 max.Process  H13 material is softer during hot forging, in order to avoid excessive bending, the production length of ordinary forging machines is not more than 9 meters, in the case of Radial forging equipment, the H13 steel forging rounds bar can reach a maximum of 15 meters.  In production, H13 ingots need slowly cooled. After ingot release mould, it need take annealed before being forged.  As delivery for clients, H13 recommends annealing + surface bright( remove the black oxide skin), because the high nickel element is prone to surface cracking.
Size & Delivery  Round Diameter Range: 80-1000mm    Length Range:15000mm  Delivery Condition: Annealed  Surface Condition: Bright  Available process: ESR (less non-metallic inclusions), PESR (less non-metallic and hazardous gas element)

Applications 

Typical applications include die casting dies for aluminium, magnesium and zinc, extrusion dies for aluminium and brass, liners, mandrels, pressure pads, followers, bolsters, die cases, die holders and adaptor rings for copper and brass extrusion.H13 is used to produce hot stamping and press forge dies, split hot heading dies, gripper dies, hot punching, piercing and trimming tools. Other applications include plastic moulds, shear blades for hot work and hot swaging dies.StandardASTM A681 Standard Specification for Tool Steel Alloy

Chemical Composition

Equivalent grades 

AISI H13 tool steel is characterized by:

High level of toughness and ductility

Good resistance to abrasion at both low and high temperatures

Good high-temperature strength

High through-hardening properties

Very limited distortion during hardening

Good resistance to thermal fatigue

Heat Treatment of Tool Steel H13

FORGING: 

Preheat slowly to 750°C then increase the temperature more rapidly to 1050-1100 °C. Do not forge below 850°C. It is essential to cool the H13 slowly after forging, either in a furnace or in vermiculite.

ANNEALING: 

Soak thoroughly at 840-860°C before furnace cooling at a maximum rate of 20°C per hour down to 600°C followed by cooling in air.

STRESS RELIEVING: 

When tools made from H13 steel are heavily machined or ground, the relief of internal strains is advisable before hardening to minimise the possibility of distortion. Stress relieving should be done after rough machining. To stress relieve, heat the component carefully to 700°C, allow a good soaking period (two hours per 25mm of ruling section). Cool in the furnace or in air. The tools may then be finish machined before hardening.

HARDENING: 

Preheat to 780-820°C. Soak thoroughly, then increase rapidly to the final hardening temperature of 1000-1030°C. When the H13 steel has attained this temperature, soak for approximately thrity minutes. Cool in air. Large sections may be quenched in oil. To reduce scaling or decarburisation, we recommend isothermal molten salt bath treatment. Preheat in salt at 780-820°C then transfer to salt bath standing at 1000-1030°C. Soak and quench into salt standing at 500-550°C. Allow to equalise, withdraw and cool in air. Alternatively, this tool steel may be vacuum hardened or pack hardened. Tools should be tempered as soon as they become hand warm.

TEMPERING: 

Heat uniformly to the required temperature allowing a soaking time of two hours per 25mm of ruling section. Withdraw from the furnace and allow to cool in air. A second tempering is strongly recommended, the H13 steel being allowed to cool to room temperature between tempers. The usual tempering range is 530-650°C depending on the hardness requirements and the operating temperature of the tool.