... , 40Cr , 35Cr Mo , 42Cr Mo, 20CrMnMo, 20CrMnTi, 17CrNiMo6, 20CrNi2Mo3.Standard of pruduction: ISO1328-19954.Smelting method: electric arc furnace + refining ... pieces must go through the GB/T6402-1999 standard ultrasonic flaw detection, grade two. If the forging pieces are within 1000 ... kgs, they can reach the GB/T6402-1999 standard, grade one ...