According to ssaw steel pipe corrosion mechanism, and it has so far proposed a variety of protective measures, such protective measures basically be divided into the following types: 1, For the environment among the harmful substances from outside to inside gradually invasive characteristics, including permeability to adopt a series of technical control template, water spray material, impermeable layers, polymer modified mortar and the like. 2, For the nature of the electrochemical corrosion of steel, steel to eliminate the use of chemical principles of fundamental electrochemical corrosion. This type of measure such as cathodic protection, electrochemical desalination (again simplified) and technology can improve the rust inhibitor of steel corrosion resistance. 3, The use of hard or corrosion resistant material wrapped or coated on the surface of steel, such as layers of reinforced epoxy, steel and other stainless steel cladding. 4, The use of low water conservation fully wet glue double-doped high-performance concrete, can significantly improve the permeability of salt. In this concrete layer having an appropriate thickness of the protective layer is to improve the durability of the basic measures.

LSAW steel pipe induction loop should be as close to the position of squeezing rollers, steel internal stress is small and evenly distributed, which can effectively prevent stress corrosion cracking, high dimensional accuracy, easy on-site welding construction, if the induction loop from the squeeze roll farther, the effective heating time is longer, wider heat-affected zone, weld strength decreases; conversely, inadequate weld edge heating, after extrusion molding adverse insufficient heat input, the weld edge is heated up to a temperature of less than weld metal structure remains remains solid, formed unfused or weld penetration; insufficient when the heat input, the weld edge is heated more than the welding temperature, resulting in over-burning or droplet weld formation Cave. . Impedance is one or a group Welded dedicated magnet impedance the cross-sectional area is usually not less than 70% of the inner cross-sectional area of the pipe, and its role is to make the induction ring, tube seam edge of the magnet forming a magnetic induction loop, generating proximity effect, the vortex heat concentrated in the vicinity of the tube weld the edges, so that the edge of the tube is heated to welding temperature. After using the pre-finish welding the welding process, welding process is stable and high weld quality. Straight seam steel pipe impedance Used in dragging a wire tube, the center position should be relatively fixed position near the center of squeeze rollers. Pipe inside burr is generally not clear. After the two edges of the tube is heated to welding temperature, oil pipes in the extrusion of squeeze rollers form a common metal grain mutual penetration, crystallization, eventually forming a strong weld. Soldering temperature is mainly affected by the high frequency eddy current thermal power, according to the correlation equation shows that the high-frequency eddy current thermal power is mainly affected by the current frequency, the eddy current heating power and current proportional to the square of the excitation frequency; and also by the current excitation frequency of the excitation voltage, current and capacitance, inductance effects. If the pressing force is too small to form a common crystal number is small, the weld metal strength is reduced by the force will produce cracking; weld burr generated by the welding and extrusion, need to be cleared. Removal method is the rack fixed cutter, pipe by rapid movement of the burr gelling. Steel tube having a longitudinal seam, inside and outside welds using a submerged arc welded.

[1] Constituting the uneven cooling of residual stress. Residual stress effect in the absence of an external force from the internal equilibrium of stress, has a cross-section of various hot-rolled steel such residual stresses, the greater cross-sectional dimension is usually steel, the residual stress is Although the greater the residual stress from equilibrium, but still there is a certain effect on the steel member function in terms of external effects such as deformation, stability, anti-fatigue effects are bad luck can happen.; [2] After the via welding, lsaw steel pipe inside nonmetallic inclusions are pressed into the sheet, showing the hierarchical representation. Stratified straight pipe joints so that the thickness direction of the tension function deteriorated significantly, and there can be reduced when the weld torn between the presentation layer. shortened weld induced strain portion reaches the yield point strain often several times larger than the load caused by the strain.

Strength and gas density of arc-shaped ssaw steel pipe is more than the general pipe, the inner wall joints smooth for air conditioning return air, fire and air and so on. High-speed fly cutting machines, no edges, no secondary processing, construction safety, diameter and high precision. Shock resistance: low-rise villas roof mostly sloping roof, so the roof structure basically is made of cold-formed steel members made of triangular roof truss system, light steel structural member after the seal plate and finished gypsum board, forming a very strong "plate rib structure system", which has a stronger seismic structural system and the ability to resist lateral loads applied to the seismic intensity of 8 degrees above areas. Wind resistance: steel structure building light weight, high strength, good rigidity, deformation ability. Only one-fifth the weight of buildings of brick and concrete structure, resistant to 70 meters per second hurricane, so that life and property can be effectively protected. Durability: light steel structure residential structure used in all cold twisted thin steel component system composed of high-strength cold-rolled steel reinforced using super corrosion galvanized sheet manufacturing, effectively avoid the effects of corrosion of steel in the construction and use of the process, increasing the light steel member life. Structural life of up to 100 years. Insulation: thermal insulation materials used in fiberglass cotton-based, with good insulation effect. For external wall insulation board, effectively prevent the wall "cold bridge" phenomenon, to achieve a better insulation effect. R15 insulation around 100mm thick cotton thermal resistance can be equivalent to 1m thick brick wall. Sound insulation: sound insulation is an important indicator to assess residential, light steel system installed windows are made of hollow glass, sound insulation, sound insulation up to 40 decibels; the wall by the light steel keel, gypsum board insulation material composed of soundproofed the effect of up to 60 decibels. Health: dry-construction, to reduce pollution caused by waste on the environment, housing material can be 100% recycled steel, other materials may also be supporting most of the recovery, in line with current environmental awareness; all materials green building materials, to meet the requirements of the ecological environment, conducive to health.

SSAW steel pipe thread is a sign of the thread on the spiral steel pipe is produced by drilling out, the use of the site to identify the thread spiral pipe is the most useful approach to the use of joint foot, this foot is a specialized tagged external thread internal thread root diameter and expanding tapered bore diameter caliper, using simple, intuitive and precise. It can also apply directly associated with long-legged steel vernier caliper ruler to measure external thread root diameter, length, thread expanding cone threaded aperture control specification query. Thread upright seen from the front direction of the helix rising distinguished threaded to rise to the right of the right-handed, left to rise for the left-handed. Spiral drill pipe thread in the production process according to API specification rules apply thread gauge inspection tasks threaded standoff, according to a certain inspection cycle using drilling screw single detector to detect the pitch and taper. Drilling screw three-digit number indicates that the Ministry of Metallurgical Industry specification method is SYB12604-63 rules connector code, known as the first digit indicates that the scale of the joint, the second digit indicates the type of joint, the third digit indicates that the table joints in threads.