CISDI Equipment Company has completed the manufacturing of a five-stand tandem cold mill for Tangshan Ganglu Steel.

The mill, delivered to the site at the end of June, is designed with six-hi stands and has multiple special features. In work rolls’ positive and negative bending, intermediate rolls’ positive bending, intermediate rolls’ shifting, rolls’ skew rolling, and hydraulically automatic gap control (AGC). These actions work in conjunction to optimise the set-up of roll gaps.

The shifting function of the intermediate rolls can adapt to different widths of strip, and ensures a high lateral rigidity of the mill. As a result, it facilitates to roll strips by a large screw-down volume and in a stable way. and a good strip profile and controlled edge thinning can be achieved.

The mill is capable of producing products ranging in thickness from 0.2mm to 2.5mm, and from 700mm to 1,300mm in width.

The tandem mill is the core equipment of a pickling line and its machining accuracy sets a precedent for other Chinese steel manufacturers.

The mill housing weighs 80.5 tonnes and is 9.3m high, a record weight for a single CISDI-manufacture component. The accuracy of the housing’s flatness, parallelism and squareness had to be to within 0.05mm per metre, which posed many challenges during machining, assembly, lifting and inspection.

To ensure accuracy, engineers and quality assurance inspectors from CISDI Equipment worked on-site to track manufacturing, handling and assembly. Multiple discussions were held to plan the safe lifting of the housing for certain procedures and specific ropes were bought for safety assurance.

Thanks to such rigorous quality and accuracy operation procedures, the housing’s installed squareness was to within 0.03mm per metre, and the gap between the housing and base plate is less than 0.02mm.

This is the second five-stand tandem cold mill supply for Tangshan Steel. The first package supply was delivered to Tangshan’s Guofeng Steel Plant in 2015 and the company were very satisfied with its high quality.

The CISDI Equipment team are pictured assembling the housing under stringent quality and accuracy controls

The five-stand six-hi tandem cold mill is delivered on schedule