SE547319C2 - Hot work tool steel - Google Patents

Abstract

An ESR-remelted hot work tool steel, which comprises the following main elements in weight %:C 0.32-0.38Si 0.05 - 0.29Mn 0.4 - 0.7Cr 5.4 -5.8Ni ≤ 0.5Mo 1.9 -2.3V 0.70-0.90Al 0.0005 - 0.030balance iron and impurities.

Claims (2)

1. weight %:C 0.32 - 0.Si 0.05 - 0.Mn 0.4 - 0.Cr 5.4 - 5.10 Ni S 0.Mo 1.9 - 2.V 0.70 - 0.Al 0.0005 - 0.N S 0.0l 15 S S 0.00l P S 0.0l O S 0.00lH S 0.Cu S 0.l20 Co S l balance Fe apart from impurities, wherein the cleanliness measured by light optical microscopy fulfils the following requirements with respect to micro-slag according to ASTM E45-97, Method A: A A B B C C D D T H T H T H T H l.0 0 l.5 l.0 0 0 l.5 l.and wherein the cleanliness measured in by scanning electron microscopy on an area of 6000 mmz fulfils the following requirements:the ECD of at least 50 % of the number of all oXide particles is S 10 um and at least 50 % of the number of all oXide particles have an ECD of S 50 um. . An ESR-remelted hot Work tool steel as defined in claim 1, Wherein the hot Work tool steel fulfils one or more of the following requirements in Weight %: C 0.33 - 0.37 Si 0.15 - 0.3 Mn 0.4 - 0.6 Cr 5.5 - 5.7 Ni S 0.Mo 2.0 - 2.

2. 2 V 0.75 - 0.85 Al 0.001 - 0.025 N S 0.S S 0.P S 0.O S 0.0012 H S 0.0003 Cu S 0.Co S 0.. An ESR-remelted hot Work tool steel as defined in claim 1 or 2, Wherein the hot Work tool steel fulfils one or more of the following requirements in Weight %: C 0.34 - 0.36 Si 0.20 - 0.28 Mn 0.45 - 0.55 Mo 2.05 - 2.15 Ni S 0.V 0.77 - 0.83 N 0.001 - 0.P S 0.008 S 0.O S 0.Cu S 0.. An ESR-remelted hot Work tool steel as defined in any of the preceding claims, Wherein the content of Mo and V in the hot Work tool steel is adjusted to fulfil the requirement Mo/V = 2.3-3.0, preferably 2.5-2. . An ESR-remelted hot Work tool steel as defined in any of the preceding claims, Wherein the cleanliness fulfils the following maximum requirements With respect to n1icro-slag according to ASTM E45-97, Method A: A B B C C D D H T H T H T H 0 l.0 0.5 0 0 l.0 0.. An ESR-remelted hot Work tool steel as defined in any of the preceding claims, Wherein the steel is in the soft annealed condition, has a mean hardness of S 230 HBWio/sooo, has a thickness of at least l00 mm and Wherein the maximum deviation from the mean Brinell hardness value in the thickness direction measured in accordance With ASTM El0-0l is less than l0 %, preferably less than 5 %, and Wherein the minimum distance of the centre of the indentation from the edge of the specimen or the edge of another indentation shall be at least two and a half times the diameter of the indentation and the maximum distance shall be no more than 4 times the diameter of the indentation. . An ESR-remelted hot Work tool steel as defined in any of claims l-5, Wherein the mean impact energy measured in the LT direction of 6 samples using a standard Charpy-V test in accordance With SS-EN lSOl48-l/ASTM E23 is at least l5 J,Wherein the Cooling time in the temperature interval of 800 °C- 500 °C (t8/5) is 1000 s.