What should you Pay Attention to During the Cold Drawing Production Process of Cold Drawn Flat Steel?

Cold-drawn flat steel refers to a steel material with a rectangular cross-section and blunt edges. Cold-drawn flat steel can be finished steel, or can be used as blanks for welded pipes and thin slabs for laminated thin plates.

Main uses: As finished products, flat steel can be used to make hoops, tools and mechanical parts. It can also be used as structural components of house frames and escalators in construction.

1. Control of cold drawing stress

When you do cold drawing of cold drawn flat steel, we must distinguish different steel bar requirements. For grade II, III, IV steel bars and No. 5 steel bars, when you cold draw them and use them as prestressed steel bars, we must remember to use cold draw stress control. And after inspection of the steel bar after cold drawing, when its cold drawing rate is not within the scope of our specifications, you should conduct mechanical energy experiments on it.

2. Cold drawing rate measurement and control requirements

When making cold-drawn flat steel, our control value must be determined by quasi-group experiments. The experiment is like this: in the same furnace and batch, the number of test specimens is greater than the latter and equal to four. Each specimen is measured according to a series of regulations to measure the cold drawing rate we need, and then the average value is taken. If the strength of the steel bars is high and the average value is below 1%, in principle, the cold drawing rate should still be controlled at 1%.

3. Cold drawing control of different batches

For mixed cold-drawn flat steel, when you can’t distinguish the batch of steel bars, when cold drawing, we need to cold-draw multiple connected steel bars, and then the cold drawing rate and control stress of each bar must comply with the specifications.

4. Cold pull speed control

When you do cold drawing flat steel, to make the steel bar fully deformed, at this time you must properly control the cold drawing speed, according to the requirements of 0.5-1.0. At the same time, when your cold drawn flat steel is cold drawn to the specified stress and cold drawing rate, this time it is necessary to stop pulling 2-3 later, then relax the steel bar, the end of the cold drawing activity, at this time, the steel bar has plenty of time for deformation.

There are many factors affecting the quality of cold drawn flat steel, including the internal quality of continuous casting billet (or blooming billet), size, shape, surface quality and stability; The stability of the outlet temperature of the heating furnace and the uniformity of the billet through heat; Also about rolling mill and rolling process.

The structural form of the mill, the stiffness of the mill design and the manufacturing precision, especially the early warning mill and the finishing mill. It is more difficult to control the tension of the rolling mill between stands in the form of group mechanical drive and its structure and manufacturing accuracy. Whether the tension of the rolled parts along the rolling direction is controlled between the mill stands.

The influence of rolling pressure on the section of cold drawn flat steel is especially great in the case of continuous double-wire rolling. Different steel materials have different rolling elongation characteristics, which have a great influence when the rolling temperature is different. Groove wear is not uniform, whether the pass design is optimized; Roll material and groove life are different; Rough rolling, middle rolling and finishing rolling stand roll groove life match is not consistent.

In addition, the structure and manufacturing precision of the guide device of cold drawing flat steel mill are also discussed. Whether the steel is cooled online after rolling and whether the heat treatment is carried out online. The cooling quality of the steel in the cold bed, the quality of the finishing process (cutting, sawing, straightening, heat treatment, polishing, marking, bundling, weighing, etc.); level of equipment, whether it is complete.

GloryRail is an professional manufacture of cold drawn, we have many years export experiences and long term cooperation clients.