Method of welding and heat treatment of sheets made of low-alloy, martensitic steel resistant to abrasive wear with boron

摘要

The purpose of the notification is the welding and heat treatment of welded sheet metal of marten steel with increased resistance to abrasion with boron, in which to produce a welded sheet of marten steel of 10 m m and expressed as a percentage by weight of the chemical composition: C-0,44-0,47; Si - 0,15-0,50; Mn - 0,45-0,55; P - max. 0.015; S - max. 0010; Cr - 0,30-0,35; Ni -1,90-2,10; Mo -0,13-0,15 B - max. 0005, and a carbon equivalent CEV 0,76, welded with the SAW method (121) with the S3Ni2,5CrMo electrode wire together with the high-density, agglomerated MgO+CaF2+Al2O3+SiO2,using welding parameters: welding speed 60 cm/min.,rated arc current I == 530-630 A, arc voltage U == 31,5-33 V, linear energy Q? 2,0 kJ/mm, the interlayer temperature Ti 250 oC, is characterized by the obtained welded joints undergoing normalisation by austenization at temperature 830-850-oC for 60min.,with cooling in the open air; further hardening by austenitisation at temperature 880/900/C by 15-20-min.,and then cooling in the oil with kinematic adhesion from 20 to 50 mm2/ s and temperature 50oC, and cooling in the temperature 100oC for 24 hours after which the mixture is cooled in the air.