What is special about quenching oil?
Quench oil serves two primary functions. It facilitates hardening of steel by controlling heat transfer during quenching, and it enhances wetting of steel during quenching to minimize the formation of undesirable thermal and transformational gradients which may lead to increased distortion and cracking.
How warm should oil be for quenching?
Quenching into oil above 212°F (100°C) has traditionally been referred to as “hot oil” quenching. Oil temperatures in the 195°F – 450°F (90°C – 230°C) range have been used with both ends of the spectrum normally reserved for special applications.
How long does quench oil last?
Oil Recovery Quenching and martempering oils deteriorate during use, although most premium quenching oils can last more than 10 years when given reasonable use and care.
Why do you preheat quench oil?
I figure preheating the oil does one of two things. It either lowers the shock for the quench, making fractures and bends less likely (hope it’s this one, because it didn’t happen) or it hardens better because it makes the oil less viscous, meaning it can transfer heat away from the blade better.
Does oil quenching harden steel?
Oil quenching is a common method for hardening alloy steel forgings. It is ideal for achieving the required strength and hardness properties on many alloys.
Can you reuse oil after quenching?
Usually, the post-quench washer is used to recover the quench oil for reuse. This washer must only be used to clean parts after the quench and must not be contaminated with other coolants or other contaminants. In this process, the oil is recovered from the post-quench wash and segregated to a separate tank.
What happens when you quench steel twice?
Double quenching indeed leads to grain refinement and overall microstructural refinement. However, the second austenization temperature must be the same or lower than the first austenization temperature to achieve this.
Can you use motor oil to harden steel?
Hardening steel with motor oil is a way of performing what is called the case hardening of steel. Pure steel is actually too soft for many applications. In order to put a hard layer on the steel, carbon must be fused at the molecular level into the top centimeter or so of the steel.
Can you over quench steel?
Often used to harden steels, water quenching from a temperature above the austenitic temperature will result in carbon getting trapped inside the austenitic lath. This leads to the hard and brittle martensitic stage.
How is quench oil characterized?
Quench oil characterization is readily performed by measuring a series of physical properties including: viscosity, water content, neutralization number, precipitation number and flash point (Table 1). In addition to physical property characterization procedures, cooling curve analysis should also be performed when needed.
What is the best way to use quenching oil for cooling?
For controlled cooling, use quenching oil instead of water to minimize cracking and distortion after heat treating parts and tools. It’s nonstaining and chlorine and sulfur free. Use full strength. Size, gal.
Can you use quench oil with sludge in it?
Although the various analyses above may indicate that a quench oil is usable, the presence of sludge may cause nonuniform heat transfer, increased thermal gradients and increased cracking and distortion. Sludge may also plug filters and foul heat-exchanger surfaces.
How do you test for quench in engine oil?
A typical elemental analysis report for metal salts contained in a quench oil is shown in Table 2. One of the oldest tests to quantify the quench severity of an oil is the GM Quenchometer (“Nickel Ball”) test which is conducted according to ASTM D3520 (Figure 3).