Pre-welding is a sawl steel pipe welding process components, it will shape the seam along the full length of the "shallow welding" is a sawl steel pipe(straight seam submerged arc welded pipe) production in one of the special car bumper manufacturers processes. If the use of chemical method to remove the glass film, we all know that the chemical properties of the glass is appropriate and stable, so the use of chemical method, then it is necessary to use strong acid or alkali properties of the liquid. Has been in Tonghua Iron and Steel 2 steelmaking development of 400 steel, in the refinery development of 1008 steel, 1015 steel. The main technical parameters are surface hardness, local hardness and effective hardening layer depth.

The market is only invisible hand can not be resolved, the more is the need for government departments from the policy-oriented, project support and so on to give greater support. But there are still a small number of enterprises, to join the Iron and Steel Association, enjoy the treatment of members is very positive, reported to the Association of statistical information, the implementation of membership obligations are not active. Large diameter pipe, can also be used flange connection. With the iron ore prices stabilized rebound, steel mills prices generally increased, slow decline in social stocks, positive factors are gradually increasing. Technological innovation depends on the new theory, the establishment of new principles, anti-corrosion steel pipe design using the transplant, combination method, in the original theory and technology based on the success. Quenching commonly used in the quenching agent are: water, oil, alkaline water and salt solution.

And from the gasoline in the steam out of steam and air mixed together, oil and gas mixture of deflagration doubled. And then the whole body heating, with a chain has been inserted into the raw material tube and with the inner core of the mandrel to complete the expansion. One reason is that thick-walled seamless steel pipe input inflation pressure is still large. The basic reasons for the quenching and deformation are: the external cooling of the straight seam steel pipe is not uniform. If the steel pipe is fixed at the time of quenching, the cooling rate of the different orientations of the steel pipe will be different, that is, the cooling is uneven and the deformation will be reduced.

Uniform, the current widely used steel pipe quenching method; steel pipe heating temperature is uneven, or quenching before the steel pipe deformation; in order to make the quenching within the spray evenly, the water should be in the steel pipe to achieve a certain flow rate, which is required by the water The amount of raw materials is not ideal, such as wall thickness deviation is too large, or bending and oval large, etc., where the wall thickness deviation is too large is the impact of quenching deformation major factor. In the price of sound everywhere, the domestic dealer to see this situation cover plate reluctant sellers, the region raised the price of steel, we seem to have been feeling, prices are a foregone conclusion.