Case Carburising & Annealing

Process Documentation

Technical Overview

Case Carburising is a thermochemical diffusion process that enriches the surface layer of low-carbon steels with carbon. This process, coupled with subsequent heat treatment, creates a high surface hardness capable of enduring severe abrasion.

Metallurgical Principles

Low-carbon steel parts are placed in our Gas Carburizing Furnaces under a controlled carbonaceous gas atmosphere. At high austenitic temperatures, carbon atoms break down from the gas phase and diffuse into the solid steel matrix. Controlled cooling or annealing is then performed to prepare the micro-structure for final machining or hardening.

Typical Thermal Cycle Parameters

Carburizing at 900-930?C in an atmosphere with carbon potential monitored at 0.8% to 1.1% C. Slow-cooled or sub-critical annealed inside the pit chamber to refine structures.

Key Component Applications

Commonly specified for: Heavy gears, spline shafts, sliding sleeves, anchor pins, and drill rods.

Process Specifications Table