IMPEDER FOR MANUFACTURING WELDED PIPE

摘要

The impeder for welded pipe production, has a laminate (10) of steel plates (8) stored in an insulated case (4). An insulated film is formed on surface of steel plate (8) of thickness 0.3 mm or less. The steel plate contains 100 ppm or less of carbon and nitrogen, 1.5-20% of chromium, 2.5-10% of silicon, 5% or less of aluminum, 1% or less of manganese and phosphorus, balance iron and unavoidable impurities.