DONGBEI SPECIAL STEEL GROUP, China

In the course of an environmental works relocation Chinese DONGBEI SPECIAL STEEL GROUP placed the order for the modernization of a continuous wire rod and bar mill originally installed in the mid 90s at DALIAN IRON & STEEL. Contractor is a consortium consisting of DANIELI & C., Buttrio / Italy and FRIEDRICH KOCKS, Hilden / Germany.

DONGBEI with headquarters in the city of Dalian is one of the top three specialty steel producers in China. In September 2004 this company was formed by a merger of DALIAN Iron & Steel, FUSHUN Special Steel and BEIMAN Special Steel. Dalian is a seaport with roughly 5.5 Mio. residents, located in Liaoning province, northeast of P.R.China (Dongbei = Chinese for northeast).

Part of this modernization is the conversion of the existing combined 300.000 t/a wire rod and bar mill into a pure bar mill. KOCKS will supply a 3-roll Reducing & Sizing Block [RSB] including accessory equipment. The 4-stand 370 mm RSB will come into operation as a finishing block behind stand No. 18. The 3-roll block will produce all finished dimensions within the range of 13 – 60 mm Ø onto the cooling bed. In the future the next extension stage will also include the production of bar in coils from 13 – 50 mm Ø.

The Reducing & Sizing Block significantly reduces the required number of pre-sections in the upstream mill and thus allows the operation of the complete mill in a simple way using a one pass family. In addition the block including the respective pass design provides the prerequisite for thermo-mechanical rolling, which is state-of-the-art for modern bar mills.

An extended “free-size” range of up to ± 1.5 mm from the nominal size allows rolling of a variety of sizes with tightest tolerances only by adjusting stands and guides by remote control. The adjustment is done automatically during a billet gap within max. 1 minute.

Whenever the finished dimensions exceed the “free-size” range the quick stand changing system allows to change stands in less than 5 minutes. Therefore, any size can be rolled without any restrictions with regard to availability of the complete mill by using a minimum number of roll sets and stand changes.

The KOCKS 3-roll RSB-technology was selected due to the extremely positive results and experiences of worldwide renowned operators. At the same time it is improving product quality, mill efficiency and market flexibility as particularly required by the automotive industry.

Start-up of the modernized bar mill including the new KOCKS 3-roll Reducing & Sizing Block is scheduled for mid of 2009.