24 June 2015 y.

New Heat Treatment Line Put into Operation at BSZ

The new normalizing-tempering line was placed into service for thermal cycling of large parts, solebars and bolsters at Bezhitsa Steel Foundry (BSZ, part of JSC Transmashholding). 

The new line has no equals at other plants of similar profile. It is designed purposely by request of Bezhitsa engineers. Its principle of operation is based on cyclic heating with accelerated cooling in special chambers, and constitutes an uniform heat treatment aimed at production of castings with improved and stable mechanical characteristics. The operator controls the process through electronic control system. 

The transfer to new manufacturing technology will provide for higher product reliability, minimize railway freight logistics risks. 

Heat cycling accelerates the diffusion process and has a positive effect on metal structuring and characteristics, thus resulting in the best combination of metal strength, impact hardness and elasticity. This is essential for the high quality and long service life of steel castings used in railway industry within the temperature range + 50°C to – 60°C. 

Development works demonstrated the effectiveness of heat cycling as compared with single-stage normalization. To assess the product compliance with specifications, the plant performed additional tests on development prototypes after heat cycling in the independent authorized testing center (All-Russian Scientific Research Institute of Railway Transport - VNIIZhT), and obtained relevant documentation confirming the new heat treatment applicability in case of railway high-duty castings.  

The Railway Equipment Registry reviewed the change in manufacturing process with application of heat cycling for large steel castings, and confirmed the validity of the conformity certificate previously obtained by the plant for bolsters and solebars.