Using the CGT-7100 to Analyze Carburizing Furnace Atmosphere

User Benefits

- Portable design with built-in sample gas pretreatment functions and sampling pump, allowing for easy analysis in any location. - Uses the same non-dispersive infrared absorption technique as continuous gas analyzers to collect highly compatible data. - Data is stored in USB flash drive convenient for editing on a computer or sharing between departments.

Introduction

Gears and other mechanical components that bear heavy loads are put through a heat treatment process called carburization to improve their resistance to wear and fatigue. Carburization increases the hardness of the outer surface of the component while maintaining the ductile structure (toughness) of its core. Heat treatment is performed in a carburizing furnace where the low-carbon steel component absorbs carbon (carburizes) into its outer surface before a quenching step. The atmosphere inside a carburizing furnace is regulated based on its carbon potential (CP), where real-time analysis and feedback control based on that analysis are essential for accurate and automated furnace operation. This article describes using the CGT-7100 portable gas analyzer to measure CO and CO₂ in the atmosphere of a drip-fed gas carburizing furnace. We used a carburizing furnace with a Shimadzu NSA-308 continuous gas analyzer that measures furnace atmosphere CO and CO₂ in real time. This data is used to calculate CP, which is used for fully automated regulation of the furnace atmosphere. This article does not describe measuring CO and CO₂ when the furnace is under fully automated control but describes measuring the change in atmosphere CO and CO₂ during a preparatory step in the carburizing process as methanol is drip-fed into the furnace.

September 2, 2021 GMT