Failure analysis of Rocker liner used as a charging system of blast furnace

• The failure sample containing non-uniform distribution of carbide.
• Wear resistance improves by increasing carbide.
• Toughness improves by increasing metallic matrix.
• Proper heat treatment with modified chemistry gives better life.

In this study, failure analysis of rocker liners used for charging system of blast furnace was carried out. The failed rocker liner samples shows non-uniform distribution of carbides, resulted in variation of hardness as well as wear properties. In the case of failed sample, the reason for the poor wear resistance of the component was due to the non-uniform carbide in pearlitic matrix. The heat treatment of failed sample was unable to affect the morphology of the primary eutectic carbides, although some dissolution of carbides and re-precipitation of secondary carbides in the matrix material has occurred. After proper heat-treatment and chemistry modification, the Rocker liner obtained high hardness (with uniformity) due to proper distribution of carbide phases in the tempered martensitic matrix. Thus, proper heat treatment is needed to achieve optimum property with changing the material composition to deal with this stringent working condition. Rocker liner with modified microstructure was trailed in the blast furnace and it has given a life of around 20–22 months life.