The main reason that restricts the service life of copper pipes

The billet continuous caster adopts a semi-plate spring imitating positive rotation vibration system, but due to the occurrence of steel breakout accidents in actual production, the vibration frame exposed to the lower mouth of the mold is most likely to be adhered to by molten steel or residual steel residues enter the vibration machinery part , It affects the accuracy of the vibration parameters, and even produces polarization, which can cause the leaf spring to break in severe cases, which will bring greater hidden dangers to the quality of the casting billet and the normal use of the copper tube.

When the vibrating leaf spring has a long service life, the leaf spring produces linear plastic extension, and the arc of the copper tube in the mold does not coincide with the basic arc of the casting machine, causing excessive resistance during drawing, resulting in transverse cracks, and the service life of the copper tube. shorten.

The stretch-straightening system of the billet continuous casting machine is mainly composed of a set of stretch-straightening upper and lower rollers, a set of free rollers, a set of stripping upper and lower rollers and frame, base, transmission system, hydraulic cylinder, etc.

Five-roll two-point straightening structure, but due to the weak maintenance power of the factory and the limited technical level, it often happens that the starter rod deviates from the lower mouth of the mold when the starter is sent, which cannot ensure the accuracy of the arc, and artificially increases the drawing resistance. , Increase the wear of the chrome plating layer of the copper pipe

The key parameter of the mold assembly is the adjustment of the water gap. The uniformity of the two sides of the water gap directly affects the quality of the cast slab and the service life of the mold. When the water gap on both sides is uneven, the molten steel is very easy to fall out due to uneven heating. Quality accidents such as deformation and corner cracks, in particular, single-stream production accidents such as steel breakout, severely restrict production and affect the quality of casting billets and the service life of mold copper tubes.

The size of the mold taper must be appropriate. Excessive taper will cause the mold to squeeze the billet shell, resulting in recessed corners, increasing the friction between the billet shell and the mold copper tube, aggravating the wear of the copper tube, and increasing the surface. Copper will form hot spots in the corner area due to the effect of the air gap, causing the blank shell to thin and crack.

A small taper will increase the air gap, reduce the heat flow, and reduce the thickness of the billet shell, which is prone to breakout. In addition, if the taper is too small, the corner rotation will be aggravated, and subcutaneous cracks and longitudinal depression will occur.