Precise control of welding temperature and pressure

Precise control of temperature and pressure

The Quality Lifeline of High Frequency Pipe Mill Machine

As the core of the step in production process, the precision of high frequency welding technology determines the quality and lifespan of the products. There will be 2 key elements influencing the final products ------ temperature and stress.

A challenge of High frequency Welding is that you can not directly measure the transient temperature at the weld point by using tradition methods. The welding temperature is usually adjusted by using out power and welding speed. For the low carbon steel, this temperature is strictly limited between 1250°C - 1460°C. The following is about the influence of welding temperature on weld seams.

• When the input heat is too low, the edge of the pipe blank cannot reach the molten state requested for welding. And the mental remains solid, leading to unwelded parts or cold cracks.
• When the input heat is large, the edge of the heater may overheat or even burn, resulting in poor welding.
• When the input heat is too high, the welding temperature is too high, breaking through the weld, causing molten metal to splash and form holes.

Welding pressure is equally important.Under the action of the extrusion roller, the tube blank heated to the welding temperature is extruded into shape. At this time, the pressure value is another key factor determining the strength and density of the weld seam.Welding pressure is selected based on the product.The extrusion pressure is generally around 20-30N/mm^2, and the extrusion pressure is adjusted by a screw. The following are the defects caused by different welding pressures.

• If the applied welding pressure is too low, the weld strength will be low and prone to cracking under stress. Furthermore, due to the low welding pressure, non-metallic impurities may remain in the weld, affecting weld strength.
• If the welding pressure is too high, the metal at both ends of the weld can be squeezed out, reducing weld quality and causing defects such as excessive internal and external burrs and cold welds.

In an increasingly competitive market, precise control of high-frequency welding temperature and pressure is no longer a simple technical option; it is a core competitive advantage that measures a company's manufacturing capabilities and ensures product safety and reliability. Only by deeply understanding and mastering the interplay of these two key elements can we achieve exceptional quality in welds measuring millimeters, even across kilometers of pipeline.