MATERIALIZING VISIONS. Bohler-Uddeholm H13 TOOL STEEL

Transcription

1 MATERIALIZING VISIONS Bohler-Uddeholm H13 TOOL STEEL

2 Bohler-Uddeholm H13 General Bohler-Uddeholm H13 is a chromium-molybdenumvanadium alloyed steel which is characterized by: Good resistance to abrasion at both low and high temperatures High level of toughness and ductility Uniform and high level of machinability and polishability Good high-temperature strength and resistance to thermal fatigue Excellent through-hardening properties Very limited distortion during hardening. Typical analysis % C 0.39 Si 1.0 Mn 0.4 Cr 5.3 Mo 1.3 V 0.9 PLASTIC MOLDING APPLICATIONS Part Austenitizing temp. HRC Injection molds Compression/ transfer molds OTHER APPLICATIONS (1,020-1,030 C Tempering 480 F (250 C Application Austenitizing temp. HRC Severe cold punching, scrap shears (1,020-1,030 C Tempering 480 F (250 C Standard specification Delivery Color code AISI H13, W.-Nr , EN X40CrMoV5-1 Soft annealed to approx. 185 HB Orange/Violet Hot shearing (1,020-1,030 C Tempering 480 F (250 C or 1,070-1,110 F ( C This grade has been manufactured to our internal specifications, and audited to meet our guidelines. Applications TOOLS FOR EXTRUSION Part Dies Backers, die-holders, liners, dummy blocks, stems Aluminium, magnesium alloys, HRC Copper alloys HRC Stainless steel HRC Shrink rings (e.g. for cemented carbide dies Wearresisting parts (1,020-1,030 C Tempering 1,070-1,110 F ( C (1,020-1,030 C Tempering 1,070 F (575 C nitrided Core Surface ~1000HV1 For applications requiring extreme levels of toughness and ductility e.g., die-casting dies and forging dies, the premiumgrades Uddeholm Orvar Supreme or Uddeholm Orvar Superior, are recommended. Austenitizing temperature (1,020-1,030 C 1,900-1,920 F (1,040-1,050 C 2

3 Properties PHYSICAL DATA Bohler-Uddeholm H13 Approximate strength at elevated temperatures longitudinal direction. Unless otherwise indicated all specimens were hardened 30 minutes at 1875 F (1025 C, quenched in air and tempered twice, for 2 h at 1130 F (610 C, with intermittent cooling to room temperature. The hardness was 45 ± 1 HRC. Temperature 68 F (20 C Density lbs/in kg/m 3 7,800 Modulus of elasticity psi 30.5 x 10 6 N/mm 2 210, F (400 C , x , F (1110 C , x ,000 Coefficient of thermal expansion per F from 68 F per C from 20 C 7.0 x x x x 10 6 Heat treatment SOFT ANNEALING Thermal conductivity Btu in/(ft 2 h F W/m C Protect the steel and heat through to 1560 F (850 C. Then cool in the furnace at 20 F (10 C per hour to 1200 F (650 C, then freely in air. MECHANICAL PROPERTIES Approximate tensile strength at room temperature. Hardness 52 HRC 45 HRC STRESS RELIEVING After rough machining the tool should be heated through to 1200 F (650 C, holding time 2 hours. Cool slowly to 930 F (500 C, then freely in air. Tensile strength(uts Rm psi kp/mm 2 tsi N/mm 2 263, , , ,420 HARDENING Pre-heating temperature: F ( C, normally in two pre-heating steps. Austenitizing temperature: F ( C, normally F ( C. Yield strength (YS Rp 0,2 psi kp/mm 2 tsi N/mm 2 220, , , ,280 Temperature F C Soaking Time Minutes Hardness before tempering 1,875 1, ±2 HRC 1,920 1, ±2 HRC * Soaking time = time at hardening temperature after the tool is fully heated through. Protect the part against decarburization and oxidation during hardening. 3

4 Bohler-Uddeholm H13 QUENCHING MEDIA High speed gas/circulating atmosphere Vacuum (high speed gas with sufficient positive pressure. An interrupted quench to equalize surface and core is recommended where distortion control and quench cracking are a concern Martempering bath or fluidized bed at F ( C, then cool in air Martempering bath or fluidized bed at approx F ( C then cool in air Warm oil Note 1: Temper the tool as soon as its temperature reaches F (50 70 C. Note 2: In order to obtain the optimum properties for the tool, the cooling rate should be fast, but not at a level that results in excessive distortion or cracks. Hardness, grain size and retained austenite as function of austenitizing temperature TEMPERING Choose the tempering temperature according to the hardness required by referring to the tempering graph. Temper twice with intermediate cooling to room temperature. Lowest tempering temperature 480 F (250 C. Holding time at temperature minimum 2 hours. Do not temper in the range F ( C. Above tempering curves are obtained after heat treatment of samples with a size of 15 x 15 x 40 mm, cooling in forced air.lower hardness can be expected after heat treatment of tools and dies due to factors like actual tool size and heat treatment parameters. Tempering within the range F ( C is not normally recommended due to the reduction in toughness properties. 4

5 DIMENSIONAL CHANGES DURING HARDENING Sample plate, 4 x 4 x 1, 100 x 100 x 25 mm. Oil hardening from 1,870 F (1,020 C min. max. Width % Length % Thickness % ± Bohler-Uddeholm H13 (480 C both result in a surface hardness of about 1100 HV 0.2. In general, plasma nitriding is the preferred method because of better control over nitrogen potential; in particular, formation of the so-called white layer, which is not recommended for hot-work service, can readily be avoided. However, careful gas nitriding can give perfectly acceptable results. Bohler-Uddeholm H13 can also be nitrocarburized in either gas or salt bath. The surface hardness after nitrocarburizing is HV 0.2. Vac hardening from 1,870 F (1,020 C min. max. Air hardening from 1,870 F (1,020 C min. max ± DEPTH OF NITRIDING Process Time Depth Gas nitriding at 950 F (510 C 10 h 30 h mm inch DIMENSIONAL CHANGES DURING TEMPERING Plasma nitriding at 895 F (480 C Nitrocarburizing in gas at 1075 F (580 C in salt bath at 1075 F (580 C 10 h 30 h 2.5 h 1 h Nitriding to case depths >0.012 inch (0.3 mm is not recommended for hot-work applications. Bohler-Uddeholm H13 can be nitrided in the soft-annealed. The hardness and depth of case will, however, be reduced somewhat in this case. Note: The dimensional changes in hardening and tempering should be added. NITRIDING AND NITROCARBURIZING Nitriding and nitrocarburizing result in a hard surface layer which is very resistant to wear and erosion. The nitrided layer is, however, brittle and may crack or spall when exposed to mechanical or thermal shock, the risk increasing with layer thickness. Before nitriding, the tool should be hardened and tempered at a temperature at least F (25 50 C above the nitriding temperature. Nitriding in ammonia gas at 950 F (510 C or plasma nitriding in a 75% hydrogen/25% nitrogen mixture at 895 F 5

6 Bohler-Uddeholm H13 Machining drill The cutting data below are to be considered as guidelines, which must be adapted to existing local s. Condition: Soft annealed to approx. 185 HB TURNING Cutting data parameters Indexable insert Type of drill Solid carbide tip 1 Cutting data parameters Turning with carbide Turning with high speed steel Cutting speed (v c f.p.m. m/min Cutting speed (v c f.p.m. m/min Feed (f i.p.r. mm/r Depth of cut (a p inch mm designation US ISO Rough turning C6-C5 P20-P30 Coated carbide Fine turning C7 P10 Coated carbide or cermet Fine turning Feed (f i.p.r mm/r Drill with replaceable or brazed carbide tip 2 Feed rate for drill diameter (20 40 mm 3 Feed rate for drill diameter (5 20 mm 4 Feed rate for drill diameter (10 20 mm MILLING Face and square shoulder milling Cutting data parameters Cutting speed (v c f.p.m. m/min Feed (f z inch/tooth mm/tooth Rough milling Milling with carbide Fine milling DRILLING High speed steel twist drill Depth of cut (a p inch mm Drill diameter Cutting speed (v c Feed (f inch mm f.p.m. m/min i.p.r. mm/r -3/ * 16-18* designation US ISO C6-C5 P20-P40 Coated carbide C6-C7 P10-P20 Coated carbide or cermet 3/16-3/ * 16-18* /8-5/ * 16-18* /8-3/ * 16-18* *For coated HSS drill v c f.p.m. (92-98 m/min. 6

7 End milling Cutting data parameters Cutting speed (v c f.p.m. m/min Feed (f z inch/tooth mm/tooth Solid carbide Type of milling indexable insert High speed steel Electrical-discharge machining EDM Bohler-Uddeholm H13 If spark-erosion is performed in the hardened and tempered, the white, recast layer should be removed mechanically e.g., by grinding or stoning. The tool should then be given an additional stress temper at approx. 50 F (25 C below the lowest tempering temperature. Welding Welding of tool steel can be performed with good results if proper precautions are taken regarding elevated temperature, joint preparation, choice of consumables and welding procedure. designation US ISO P20, P30 1For coated HSS end mill v c = m./min. ( m/min. 2Depending on radial depth of cut and cutter diameter. Welding method TIG MMA Preheat temperature Filler material F ( C QRO 90 TIG-WELD DIEVAR TIG-WELD F ( C QRO 90 WELD GRINDING General grinding wheel recommendations is given below. Wheel selection Cooling rate Hardness after welding F/h (20 40 C/h the first 2 3 h then freely in air HRC HRC Type of grinding Face grinding straight wheel Face grinding segments Wheel recommendation Soft annealed A 46 HV A 24 GV Hardened A 46 HV A 36 GV Post weld heat treatment Hardening Soft annealed Temper at 50 F (28 C below the lowest original tempering temperature. Soft-anneal the material at 1560 F (850 C in protected atmosphere. Then cool in the furnace at 20 F (10 C per hour to 1200 F (650 C then freely in air. Cylindrical grinding A 46 LV A 60 KV Internal grinding A 46 JV A 60 IV Profile grinding A 100 LV A 120 KV 7

8 Bohler-Uddeholm H13 Hard-chromium plating After plating, parts should be tempered at 400 F (200 C for 4 hours within 4 hours of plating to avoid the risk of hydrogen embrittlement. Texturing Bohler-Uddeholm H13 is particularly suitable for texturing by the photo-etching method. Its high level of homogeneity and low sulphur content ensures accurate and consistent pattern reproduction. Polishing Bohler-Uddeholm H13 exhibits good polishability in the hardened and tempered. Polishing after grinding can be effective using aluminum oxide or diamond paste. Typical procedure: 1. Rough grinding to grain size using a wheel or stone. 2. Fine grinding with abrasive paper or powder down to grain size. 3. Polish with diamond paste with a grain size of 15 µm using a polishing tool of soft wood or fiber. 4. Polish with diamond paste with a series of finer grain sizes e.g., µm using a polishing tool of soft wood or fiber. 5. When demands on surface finish are high, a 1µm diamond paste can be used for final polishing with a fiber polishing pad. 8

9 BOHLER-UDDEHOLM CORPORATION 2505 Millennium Drive, Elgin, IL The Steel Store This information is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should not therefore be construed as a warranty of specific properties of the products described or a warranty for fitness for a particular purpose. The latest revised edition of this brochure is the English version, which is always published on our web site Edition 1,