Forged Part Heat Treatment Process

Depending on the steel grade and process requirements, forgings commonly undergo the following heat treatment methods: annealing, normalizing, tempering, quenching followed by low-temperature tempering, and quenching combined with aging. Next, let’s take a closer look at how each of these processes is carried out:

Depending on the steel grade and process requirements, forgings commonly undergo the following heat treatment methods: annealing, normalizing, tempering, quenching followed by low-temperature tempering, and quenching combined with aging. Next, let’s take a closer look at how each of these processes is carried out:

1. Annealing:

Forged parts Annealing The processes include various forms such as full annealing, spheroidizing annealing, low-temperature annealing, and isothermal annealing, which must be selected based on the material of the forging and its deformation conditions.

After annealing, the forging undergoes recrystallization, which refines the grain structure and eliminates or reduces residual stresses. As a result, the hardness of the forging is reduced, while its plasticity and toughness are enhanced, and its machinability is improved.

2. Normalizing:

Normalizing generally involves heating the forging to... GSE Above the line 50-70℃ Some high-alloy steel forgings are heated to... GSE Above the line 100–150℃ After proper heat preservation, it is then cooled in air. If the forging exhibits high hardness after normalizing, to reduce its hardness, a high-temperature tempering treatment should also be performed; generally, the tempering temperature is... 560–660℃ 。

3. Quenching, tempering ：

Quenching is performed to obtain a non-equilibrium microstructure, thereby enhancing strength and hardness. The steel forging is heated to... Ac1 Above the line 30-50℃ After being kept warm, it is rapidly cooled.

Tempering is performed to relieve quenching stresses and obtain a more stable microstructure. The forging is heated to... Ac1 Heat to a temperature below the line, hold at that temperature for a certain period, then cool in air or by rapid cooling.

4. Quenching, aging:

High-temperature alloys and alloys that can be strengthened by heat treatment often undergo quenching and aging treatments after forging. Quenching involves heating the alloy to an appropriate temperature, holding it at that temperature long enough to ensure that certain microstructural constituents dissolve into the matrix, thereby forming a homogeneous solid solution. The alloy is then rapidly cooled to produce a supersaturated solid solution—hence the term "solid-solution treatment." The purpose of this treatment is to improve the alloy's ductility and toughness and to prepare its microstructure for subsequent aging treatment. Aging treatment entails placing the supersaturated solid solution or the alloy that has undergone cold working deformation at room temperature or at an elevated temperature for a specified period, allowing the substances previously dissolved in the matrix to precipitate uniformly and finely dispersed throughout the matrix. The goal of aging treatment is to enhance the alloy's strength and hardness.

Forged part heat treatment It is carried out according to specific heat treatment specifications, which are formulated based on the steel grade of the forging, its cross-sectional dimensions, technical requirements, and with reference to relevant manuals and data. The content includes: heating temperature, holding time, and cooling method, among others. Typically, temperatures are used... - It is represented by a time-varying curve.