A NEW SOLUTION FROM VILLARES METALS FOR EXTRUSION DIES. Better temper resistance (resistance to softening at elevated service temperatures);

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2 Villares Metals Is a Brazilian company providing solutions in long products made from high alloy steels and specialty alloys. Villares is part of the Special Steel Division of the voestalpine Group, based in Linz (Austria). Our special steels and specialty alloys are available in a wide variety of sizes and product forms. Villares Metals products are engineered to deliver outstanding performance in the most demanding applications, supplying major industry segments including automotive, tooling, oil and gas, aerospace, and capital goods both in Brazil and worldwide. Our advantage is found in our technical expertise, flexibility and capacity to develop innovative solutions to meet customer needs.

3 A NEW SOLUTION FROM VILLARES METALS FOR EXTRUSION DIES VEX is a new hot work tool steel developed for the hot extrusion application area, mainly for the manufacture of aluminum extrusion dies where conventional H13 is used. The chemical composition of VEX is optimized to provide superior properties including: Better temper resistance (resistance to softening at elevated service temperatures); Excellent nitriding response including increased surface hardness and deeper nitride case; High wear resistance to give longer tool life; Strength and toughness comparable to our H13. VEX = VILLARES METALS + EXTRUSION.

4 ALLOY DESIGN In the manufacturing of aluminum extrusion dies, the AISI H-class type grades are often employed and conventionally produced H13 is the most widely used grade. VEX was specifically developed to improve upon H13, with carefully controlled levels of carbon, chromium, molybdenum and aluminum. These changes were designed to provide optimized extrusion performance. Table 1: Standards and typical chemistry (%) Steel A/SI DIN WNr C Si Mn Cr Mo V Al VH13 H VEX VEX also provides better temper resistance than H13, as shown in Figure 1. VEX is ideal for applications involving long periods of exposure at elevated temperatures, due to its ability to maintain high hardness and wear resistance at the service temperature. 50 Temper resistance of VEX and Villares H13, VH13ISO Hardness (HRC) VEX VH13ISO Time at 600 C [1110 F] in hours Figure 1: Tempering resistance chart. Test performed with samples in different times at 600 C [1110 F]. VEX is heat treated by quenching and tempering, followed by nitriding. These heat treatment procedures provide longer service life. Figure 2 shows the tempering curve of VEX with previous austenitizing at 1020 C (1868 F). Additional information is available in the material s technical data sheet on

5 Tempering temperature (ºF) Hardness (HRC) Tempering temperature ( C) Figure 2: Curve obtained from specimens with cross section of 20 x 20 mm 2. Tempering time: 2 hours. VEX contains aluminum additions and other chemistry modifications to provide superior nitriding response compared to H13. The higher surface hardness and deeper case of nitrided layer improves wear resistance and leads to a longer tool life by reducing washout and wear, and reducing the number of nitriding cycles required to achieve similar production volume. Figure 3 shows the nitriding profile achieved for VEX and H13 steels after submitted to the same gas nitriding cycle.

6 GAS NITRIDING VEX versus H13 hardness profile 1400 Hardness (HV) C (990 F) for 8 hours - atmosphere N2 and H2 Increased surface hardness Deeper nitrided layer Distance from the surface (μm) H13 VEX Figure 3: Hardness profile obtained for VEX and VH13ISO Mechanical Properties Toughness with Charpy V notch testing Tests performed in the hardness range of HRC. The impact toughness of VEX exceeds the industry average of conventional H13 and is comparable to VH13ISO (the extra fine structure H13 grade from Villares), as shown in Figure Impact energy (J) H13 (avarege market) VH13ISO VEX Figure 4: Absorbed energy after impact test of VEX and H13 steels.

7 FIELD TESTS Field testing was conducted to corroborate the laboratory test results for tool life. The results for H13 and VEX are compared in Table 2 and Figure 5, for a tool used in the production of a hollow die. Dies manufactured in VEX and H13 Aluminum Class: AA 6060 T5 Figure 5: On the right side is the drawing of a hollow extrusion die manufactured in VEX steel, and on the left side the profile drawing which was extruded in industrial scale. Table 2: Comparative extrusion performance after using H13 and VEX steels in the extrusion dies. Steel grade H13 average performance VEX average performance Production life in kg Number of re-nitridings

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