Typical example of flame correction for steel structural parts (5)

The second lecture is the correction of the deformation of the column workpiece (2)   

4. Correction of bidirectional deformation of box-shaped column

There are many types of box-shaped columns, which are composed of different types of steel bars and steel plates of different thicknesses. The smaller steel profiles often produce two-way deformation, as shown in Figure 16.

To correct the bidirectional deformation of the column, the method of baking the 90° line on both sides of the deformed column (both sides of the column) can be used to reduce the number of heating zones and improve work efficiency.

The correction specification is shown in Fig. 16. The correction of the bidirectional deformation f1 is a right angle heating zone, and the heating form is a single wire belt, which is heated only by the heating zone of the wire strip on the two arch faces of the deformation part; f2 is a one-way deformation, and the conventional one is used. The method of combining triangle and wire; for small deformation, it is corrected by single wire heating method.

5. Correction of deformation of plate strut

The plate-stacked column is a column which is welded by a steel plate on four sides. When the plate is erected, the heating area is smaller than that of the same-section steel column.

The correction specification for the deformation of the plate strut is shown in Figure 17. The triangular heating zone should be baked on both sides of the column with the same vertical line as the heating zone of the belt. The heating zone is completely red.

Figure 17 is a correction of the local deformation of the plate strut. The column has only two planes that are not straight, f1 is the correction of pure two sides, and the double triangle combination heating method is used to correct the deformation perpendicular to the heating zone after correction, using a single line method; f2 is the large deformation of both sides of the column The deformation amount of the other two sides is small, and the triangular-plus-belt heating zone is used for the large deformation amount, and the wire heating zone is adopted for the small deformation amount, the heating sequence is the first triangle, and the rear line has the heating zone.

6. Heavy column deformation correction

Heavy-duty columns (Fig. 18) After assembly, the rigidity is extremely strong. Before the assembly, the profile steel should be carefully corrected, especially for the I-beam which is the intermediate support.

In Fig. 18, f1 is the vertical bending of the column, f2 is the local deformation caused by the irregularity of the I-beam, and f3 is the deformation of the column caused by the vertical bending of the intermediate-supported I-beam. For the correction of f1 deformation, the strong heating zone specification of deep triangle widening belt is adopted; for the correction of f2 deformation, the small triangle widening zone specification of local correction is adopted; for the correction of f3 deformation, the strong heating zone of wide belt is adopted. specification.

In the heating zone of the workpiece, the heating time should be increased when the steel plate and the profile steel overlap, so that the heating zone is red-transparent and the correcting ability is improved.

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Tapping Screw

Although there are many types of tapping screws, they all have the following similarities:
(1) are generally made of carbonized carbon steel (accounting for 99% of total production). It can also be made of stainless steel or non-ferrous metals.
(2) The product must be heat treated. Carbon steel tapping screws must be carbonized and stainless steel tapping screws must be solution hardened. In order to make tapping screws to meet the requirements of the standard of mechanical properties and performance.
(3) The product surface hardness is high, the core toughness is good. That is, "soft inside strong outside". This is a major feature of tapping Screw performance requirements. If the surface hardness is low, it can not be screwed into the matrix; If the core toughness is poor, a twist will break, can not be used. So "inside soft outside steel" is self-tapping screw to meet the use of performance, very important requirements.
(4) The surface of the product needs surface protection treatment, generally electroplating treatment. Some product surface must be treated by phosphate (photostatting), such as wall panel self - tapping screws for photostatting.
(5) Production by cold heading process. It is recommended to use high-speed cold heading machine and high-speed wire rolling machine or high-speed planetary wire rolling machine. High speed is emphasized here to ensure product quality. Only the head of tapping screw produced by high-speed machine is well formed and the thread quality is high.