What is oil hardening steel ?

Usually, when some needs oil hardening steel, he probably means AISI O1 cold work steel.

O1 Tool Steel is a very good cold work steel and also makes very good knives and forks. It can be hardened to about 57-61 HRC. And you can check full data for AISI O1 tool steel here.

Then,

What is Oil Hardening ?

Oil quench hardening is a common method for hardening alloy steel forgings. It’s ideal for achieving the required strength and hardness properties on many alloys with less risk of cracking than water or polymer quench processes.

Capability

We need to run all oil hardening processes in our numerous batch-type internal quench atmosphere furnaces, which are ideal for process and lot control.  All furnaces are certified to meet the temperature uniformity and accuracy requirements of AMS 2750, and our largest furnace capable of performing oil quench hardening has internal working dimensions of 36”W x 72”L x 42”H and can handle weights of up to 7000  pounds.

Process

The process of oil quench hardening for forgings is performed by first fully austenitizing the steel in the temperature range of 1500°F – 1650°F depending on the steel grade. It is held at this temperature for a time proportionate with the part cross-section.

The entire austenitizing process is typically carried out under a protective carbon-controlled atmosphere that prevents excessive scale formation on the forged surface. Once soaked at the austenitizing temperature for the appropriate amount of time, the load is quenched in agitated oil to produce a fully hardened martensitic microstructure, the depth of which is dependent on the alloy grade and section thickness. From this point, the parts are tempered down to the specified hardness range to improve toughness.

In cases where parts are especially distortion sensitive or crack-prone, we will custom-tailor an oil quench process to minimize or eliminate these problems completely while still achieving the required material properties. For extreme distortion tolerances or unique property requirements, take a look at our marquench hardening or austempering services.