What Is a Tempering Furnace? Definition, Purpose & Working Principle

A tempering furnace is special industrial heat treatment equipment matched with quenching process, mainly used for tempering treatment of quenched steel and alloy parts to adjust metal mechanical properties. Many people confuse tempering furnaces with annealing furnaces, but their core purposes and process temperatures are completely different in industrial applications.

The core working principle of a tempering furnace is low and medium temperature heating below the metal recrystallization point. After quenching, metal parts have ultra-high hardness but extremely poor toughness and severe brittleness, accompanied by huge quenching residual stress. If used directly, the parts are prone to sudden fracture and fatigue failure.

The tempering furnace heats quenched workpieces at a constant temperature ranging from 150℃ to 650℃. This process releases quenching stress, stabilizes the internal martensite structure of the metal, balances hardness and toughness, and eliminates the brittleness of quenched parts. According to different temperature ranges, tempering is divided into low-temperature tempering, medium-temperature tempering and high-temperature tempering to meet different industrial performance requirements.

Industrial tempering furnaces include box type batch tempering furnaces and continuous mesh belt tempering furnaces, suitable for small-batch customized parts and large-scale mass production respectively. Standard tempering treatment greatly improves the service stability and fatigue resistance of molds, gears, shafts and hardware tools, which is an essential post-quenching process.

FAQ

Q1: What is the main purpose of a tempering furnace?

A1: Eliminate quenching stress, reduce brittleness, and balance metal hardness and toughness after quenching treatment.

Q2: Is tempering necessary after quenching?

A2: Yes, untempered quenched parts are extremely brittle and easy to crack during use.