What Is the Tempering Process? Step-by-Step Industrial Guide

The tempering process is a standard secondary heat treatment procedure for quenched metal parts, serving as the key step to optimize quenching quality and stabilize metal performance. Strictly speaking, complete metal heat treatment must include quenching and tempering matching processes, and the tempering process directly determines the final mechanical properties of industrial steel parts.

The complete tempering process is divided into three steps: workpiece pre-inspection, constant temperature tempering heating, and uniform cooling. First, workers inspect quenched workpieces to eliminate defective parts with quenching cracks and severe deformation, ensuring the qualification of tempering raw materials.

The second step is core constant temperature heating. Place qualified quenched parts into a professional tempering furnace, raise the temperature to the targeted process range and keep warm stably. Low-temperature tempering (150-250℃) maintains high hardness and wear resistance for tools and molds; medium-temperature tempering (350-500℃) improves elasticity for spring parts; high-temperature tempering (500-650℃) achieves high toughness and strength balance for structural parts.

The final step is uniform cooling. After heat preservation, workpieces are cooled steadily with furnace cooling or air cooling to avoid new stress caused by rapid temperature change. Standard tempering process can completely eliminate quenching residual stress, stabilize metal microstructure, prevent size deformation during long-term use, and significantly improve workpiece fatigue life.

FAQ

Q1: What are the three types of tempering processes?

A1: Low-temperature tempering, medium-temperature tempering and high-temperature tempering for different industrial usage scenarios.

Q2: Why is tempering process critical?

A2: It fixes the brittleness defect of quenched parts and realizes stable and durable mechanical performance.