Key points of production process of spiral welded pipe

Spiral welded pipe, also known as SSAW pipe, is a type of steel pipe with a spiral seam, created from strip steel coil. It is manufactured using an automatic double-wire, double-sided submerged arc welding process and is extruded at room temperature. These pipes are primarily used in water supply engineering, the petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction.

Main Process Characteristics of Spiral Welded Pipe

Minimal Residual Stress: The molding process results in low residual stress and a scratch-free surface. The spiral welded pipe excels in meeting varied requirements for diameter and wall thickness, offering advantages in size and specification range.

Advanced Welding Technology: The use of double-sided submerged arc welding technology addresses potential defects, making it easier to control welding quality.

Quality Inspection: Each steel pipe undergoes a 100% quality inspection, ensuring high product quality.

Real-time Data Transmission: All equipment in the production line is networked with a computer data acquisition system, allowing real-time data transmission and control of technical parameters from the control room.

Heating Process

During the heating process, it is crucial to select appropriate heat treatment equipment and heating mediums. Common issues include the oxidizing effect of the heating medium on the part's surface and exceeding the process-required heating temperature. Excessively thick austenite grains or melting grain boundaries can severely affect the part's appearance and internal quality. Feasible measures should be taken to address and prevent such defects.

Tempering Process

Parts that are defective during tempering are quenched to obtain a high-hardness martensite structure or a slightly lower hardness bainite structure, which are unstable and brittle. The tempering process aims to achieve the desired structure and properties. Tempering process parameters significantly impact heat treatment quality, including hardness, tempering brittleness, and the occurrence of tempering cracks. Measures should be taken to avoid these defects.

Corrective Actions

Ensuring a correct heat treatment process is fundamental for achieving qualified heat treatment quality. Quality issues should be addressed by analyzing and correcting factors related to personnel, machinery, materials, methods, links, and inspections to identify and rectify the root causes of defects.

Storage Guidelines for Spiral Welded Pipe

Storage Location: Store spiral steel pipe products in a clean, well-drained area. Clear the area of weeds and debris. Keep the steel bars clean and away from factories and mines that produce harmful gases or dust.

Avoid Corrosive Materials: Do not store materials that corrode steel, such as acid, alkali, salt, and cement, in the same warehouse. Different types of steel should be stacked separately to prevent confusion and contact corrosion.

Ventilated Storage: Small and medium-sized section steel, wire rod, steel bar, medium-diameter steel pipe, steel wire, and wire rope should be stored in a well-ventilated shed after proper cushioning.

High-value Storage: Store small steel, thin steel plates, steel strips, silicon steel sheets, or thin-walled spiral steel pipes properly. High-value, corrosive cold-rolled and cold-drawn steel and metal products should be stored with care.