Fracture Analysis of High Chromium Cast Iron Roll on CSP Mill

A roll barrel breakdown accident took place on CSP mill. After investigating of the accident scene and the roll service condition, analysing the barrel fracture and sampling tests, proved that main cause for the roll breakdown was unusual and there appeared a strip-like crack on the boundary layer resulting from the initial flaws extending along the roll circle direction; furthermore, the flaws caused fatigue breakage along the roll inner cross section, which resulted in the barrel breakdown.

Study on Structure and Properties of Alloy Nodular Cast Iron Roller with Laser Heat Treatment

The microstructure analysis and hardness test were carried out on the surface of alloy nodular cast iron roll treated with CO2 laser of power 5 KW by optical microscopy, Rockwell hardometer and micro-hardometer. The results indicate the cladded layers with laser heat treatment are divided into melt region, phase change region and substrate region. The dimension and microhardness for every region are related to laser power, scanning speed and process parameters. The fatigue life of alloy nodular cast iron roll treated with laser increased remarkably.