Surface Hardfacing Technology for Continuous Casting Machine Guide Roller Sleeves

Literature Overview

This paper by Tang Qiong and Ma Jinglan from Taiyuan Iron and Steel Group, published in Shanxi Metallurgy (1998, Vol. 21, No. 4, pp. 33-34), addresses a critical challenge in domestic steelmaking equipment: the surface stainless steel hardfacing of guide roller sleeves for imported continuous casting machines. At the time of publication, China had no successful domestic experience in this area, making the imported roller sleeves both expensive and subject to long lead times. The authors describe how they modified existing equipment and conducted comparative trials using different welding parameters and hardfacing materials to produce qualified spare parts that could replace imported components.

Core Technical Content

The guide roller sleeves in continuous casting machines operate under severe conditions involving high-temperature molten steel contact, thermal cycling, mechanical friction, and mechanical loading from the cast strand. Surface hardfacing with stainless steel provides a wear-resistant and corrosion-resistant layer that extends the service life of these critical components significantly. The authors systematically evaluated multiple hardfacing materials and process parameter combinations to identify the optimal solution for domestic production.

Key Process Parameters and Materials

The authors emphasize that the selection of hardfacing material must balance hardness, toughness, and resistance to thermal cracking. Stainless steel hardfacing deposits typically contain chromium levels between 18-25 percent, which provide sufficient oxidation resistance for the high-temperature environment near the molten steel. The dilution rate between the base metal and the hardfacing deposit is a critical factor; excessive dilution reduces the effective alloy content and diminishes the wear resistance benefits of the overlay.

Engineering Practice Insights

From a metallurgical perspective, the hardfacing of roller sleeves requires careful consideration of the heat-affected zone (HAZ) properties. The thermal cycles associated with hardfacing can cause microstructural changes in the base metal, potentially leading to hardness increases and reduced toughness near the weld interface. The authors' approach of modifying existing equipment rather than purchasing new specialized hardfacing equipment reflects a pragmatic engineering philosophy that is highly relevant to cost-conscious manufacturing environments.

The comparative trial methodology employed in this study follows a systematic approach: multiple material and parameter combinations were tested, evaluated through hardness measurements, microstructural examination, and service performance assessment. This approach aligns with the PDCA (Plan-Do-Check-Act) cycle commonly used in quality improvement initiatives.

Study Insights and Implications

This paper demonstrates that with proper material selection and process optimization, domestically produced hardfaced components can meet or exceed the performance of imported equivalents. The economic benefits are substantial, as the cost of domestically produced hardfaced roller sleeves is significantly lower than the import cost, and the supply chain is more reliable. For engineers working on similar hardfacing applications in steelmaking equipment, the key takeaway is that systematic parameter optimization and material evaluation are essential for achieving reliable results, especially when working without prior domestic experience. The methodology described here remains relevant for modern hardfacing applications where cost reduction and supply chain security are critical considerations.