Selection of Tool Steels - Houston Area Blacksmiths ...

1 June 19, 2004 HABA1 Selection of tool SteelsSelection of tool SteelsFitness for PurposeFitness for PurposebybyTom Tom FarraroFarrarofor for Houston Area Blacksmiths Association Houston Area Blacksmiths Association Meeting June 19, 2004 Meeting June 19, 2004 June 19, 2004 HABA2 Desirable Properties of tool SteelsDesirable Properties of Desirable Properties of tool SteelsTool Steels Hardness -Resistance to Deforming & Flattening Toughness -Resistance to Breakage & Chipping Wear -Resistance to Abrasion & Erosion Corrosion -Resistance to Rusting and Pitting Hardness -Resistance to Deforming & Flattening Toughness -Resistance to Breakage & Chipping Wear -Resistance to Abrasion & Erosion Corrosion -Resistance to Rusting and PittingJune 19, 2004 HABA3 tool steel ClassificationsTool steel ClassificationsTool steel Classifications Water Hardening tool Steels (W) Shock Resisting tool Steels (S) cold work tool Steels (O, A, D) Hot work tool Steels (H) High Speed tool Steels (T, M) Low Alloy Tools Steels (L) Mold tool Steels (P) Stainless steel tool Steels (3xx, 4xx) Water Hardening tool Steels (W) Shock Resisting tool Steels (S) cold work tool Steels (O, A, D) Hot work tool Steels (H) High Speed tool Steels (T, M) Low Alloy Tools Steels (L) Mold tool Steels (P) Stainless steel tool Steels (3xx, 4xx)

2 June 19, 2004 HABA4 Alloying Elements in Tools SteelsAlloying Elements in Tools SteelsAlloying Elements in Tools Steels CarbonC+Strength, +Hardenability, -Toughness ChromiumCr+Strength, +Hardenability, +Corrosion Resistance - Toughness MolybdenumMo+Strength, +Hardenability, +Toughness, +Hot Hardness VanadiumV+Hardenability, +Toughness, +Hot Hardness, +Wear TungstenW+Strength, +Hardenability, +Hot Hardness, -Toughness CobaltCo+Hot Hardness, +Wear, -Toughness ManganeseMn+Strength, +Hardenability, +Toughness NickelNi+Hardenability, +Toughness, +Corrosion Resistance CarbonC+Strength, +Hardenability,-Toughness ChromiumCr+Strength, +Hardenability, +Corrosion Resistance - Toughness MolybdenumMo+Strength, +Hardenability, +Toughness, +Hot Hardness VanadiumV+Hardenability, +Toughness, +Hot Hardness, +Wear TungstenW+Strength, +Hardenability, +Hot Hardness,-Toughness CobaltCo+Hot Hardness, +Wear, -Toughness ManganeseMn+Strength, +Hardenability, +Toughness NickelNi+Hardenability, +Toughness, +Corrosion ResistanceJune 19, 2004 HABA5 Hardness, Hardenability, ToughnessHardness, Hardenability, ToughnessHardness, Hardenability, Toughness Hardness-ability of a steel to resist deformation under load.

3 The hardness is directly proportional to the amount of martensitepresent in the steel microstructure. Hardenability-ability of a steel harden ( form martensite to the desired depth) during heat treatment. Toughness-is the relative resistance of a material to breakage, chipping, or cracking under impact or stress. Toughness may be thought of as the opposite of brittleness. Hardness-ability of a steel to resist deformation under load. The hardness is directly proportional to the amount of martensitepresent in the steel microstructure. Hardenability-ability of a steel harden ( form martensite to the desired depth) during heat treatment. Toughness-is the relative resistance of a material to breakage, chipping, or cracking under impact or stress. Toughness may be thought of as the opposite of brittleness. June 19, 2004 HABA6 Hardness vs. %Carbon in SteelHardness vs. %Carbon in SteelHardness vs.

4 %Carbon in SteelJune 19, 2004 HABA7 ToughnessToughnessToughnessToughness -is the relative resistance of a material to breakage, chipping, or cracking under impact or stress. Toughness may be thought of as the opposite of brittleness. Factors which affect Toughness are: Tempering tempered martensite is tougher than untempered martensite. Grain Size and Orientation Coarse (large) grains give poor toughness, fine small grains give good toughness. Carbide Dispersion coarse, segregated, poorly dispersed carbides, lead to low toughness. Fine evenly dispersed carbides give improved -is the relative resistance of a material to breakage, chipping, or cracking under impact or stress. Toughness may be thought of as the opposite of brittleness. Factors which affect Toughness are: Tempering tempered martensite is tougher than untempered martensite. Grain Size and Orientation Coarse (large) grains give poor toughness, fine small grains give good toughness.

5 Carbide Dispersion coarse, segregated, poorly dispersed carbides, lead to low toughness. Fine evenly dispersed carbides give improved 19, 2004 HABA8 Toughness is Directly Proportional to Grain SizeGrain size is Determined by the Austenization TemperatureToughnessToughnessis Directly Proportional to Grain Sizeis Directly Proportional to Grain SizeGrain size is Determined by the Grain size is Determined by the AustenizationAustenizationTemperatureTem peratureAISI 1025 steel 500X Austenitized at 2000 FAISI 1025 Steel500X Austenitized at 1700 FJune 19, 2004 HABA9 Grain SizeGrain SizeASTM Grain Size NumbersASTM Grain Size NumbersJune 19, 2004 HABA10 Choosing Steels for ToughnessChoosing Steels for ToughnessChoosing Steels for HardnessChoosing Steels for HardnessJune 19, 2004 HABA11 Wear ResistanceWear ResistanceWear Resistance Intuitively expect that a harder tool will resist wear better than a softer tool .

6 However, different grades, used at the same hardness, provide varying wear instance, O1, A2, D2, and M2 would be expected to show increasingly longer wear performance, even if all were used at 60 HRC. In fact, lower hardness, high alloy grades may outwear higher hardness, lower alloy grades. Intuitively expect that a harder tool will resist wear better than a softer tool . However, different grades, used at the same hardness, provide varying wear instance, O1, A2, D2, and M2 would be expected to show increasingly longer wear performance, even if all were used at 60 HRC. In fact, lower hardness, high alloy grades may outwear higher hardness, lower alloy grades. June 19, 2004 HABA12 Carbides Effect Wear ResistanceCarbides Effect Wear ResistanceCarbides Effect Wear ResistanceAlloy elements (Cr, Mo, V, W) form hard carbide particles in tool steel microstructures. Wear Resistance is influenced by: Type carbides (harder is better) Amount of carbide present (more is better) Dispersion of carbides (finer is better) In the microstructure of the steelAlloy elements (Cr, Mo, V, W) form hard carbide particles in tool steel microstructures.

7 Wear Resistance is influenced by: Type carbides (harder is better) Amount of carbide present (more is better) Dispersion of carbides (finer is better) In the microstructure of the steelJune 19, 2004 HABA13 Hardness of CarbidesHardness of CarbidesHardness of Carbides HARDENED steel 60/65 HRC CHROMIUM CARBIDES 66/68 HRC MOLYBDENUM CARBIDES 72/77 HRC TUNGSTEN CARBIDES 72/77 HRC VANADIUM CARBIDES 82/84 HRC HARDENED steel 60/65 HRC CHROMIUM CARBIDES 66/68 HRC MOLYBDENUM CARBIDES 72/77 HRC TUNGSTEN CARBIDES 72/77 HRC VANADIUM CARBIDES 82/84 HRC June 19, 2004 HABA14 Effect of Carbide Content on Effect of Carbide Content on Wear ResistanceWear ResistanceHRC 58 HRC 58--62 except as noted62 except as notedJune 19, 2004 HABA15 Conventional vs. Powder (CPM) steel Making MethodsConventional vs. Powder (CPM) Conventional vs. Powder (CPM) steel Making MethodsSteel Making MethodsCONVENTIONALCPMC arbide Dispersion ComparisonJune 19, 2004 HABA16 ToughnessToughnessCPM vs.

8 ConventionalCPM vs. ConventionalJune 19, 2004 HABA17 Corrosion ResistanceCorrosion ResistanceCorrosion ResistanceCr (not Cr carbide) is the primary element which influences corrosion resistance of a Cr -No significant effect on resistance to rusting. 4-11% Cr -Moderate improvement in resistance to rusting will still Cr -Stainless steel - resistant to rusting and stainingCr (not Cr carbide) is the primary element which influences corrosion resistance of a Cr -No significant effect on resistance to rusting. 4-11% Cr -Moderate improvement in resistance to rusting will still Cr -Stainless steel - resistant to rusting and stainingJune 19, 2004 HABA18 cold work tool Steels Composition and PropertiesCold work tool Steels cold work tool Steels Composition and PropertiesComposition and PropertiesAISI GRADE NAME C Cr Mo V W OTHER WEAR RESISTANCE TOUGHNESS L6 CHAMPALOY Ni O1 KETOS O6 HALGRAPH S5 LABELLE SIL #2 Si A9 CRUCIBLE A9 Ni S7 CRUCIBLE S7 S7 PREM CRUCIBLE S7 XL S maxA6 CSM 6 Mn A2 (S) AIRKOOL (S) CPM 1V D2 (S) AIRDI 150 (S) CRU-WEAR CPM 3V M2 REX M2 (S) M4 CPM M4HC(HS)

9 CPM 9V T15 CPM T15 Co A11 CPM 10V CPM 15V 4140 MOD MAXEL TOOLING ALLOY 52100 52100 AISI GRADE NAME C Cr Mo V W OTHER WEAR RESISTANCE TOUGHNESS L6 CHAMPALOY Ni O1 KETOS O6 HALGRAPH S5 LABELLE SIL #2 Si A9 CRUCIBLE A9 Ni S7 CRUCIBLE S7 S7 PREM CRUCIBLE S7 XL S maxA6 CSM 6 Mn A2 (S) AIRKOOL (S) CPM 1V D2 (S) AIRDI 150 (S) CRU-WEAR CPM 3V M2 REX M2 (S) M4 CPM M4HC(HS) CPM 9V T15 CPM T15 Co A11 CPM 10V CPM 15V 4140 MOD MAXEL TOOLING ALLOY 52100 52100 June 19, 2004 HABA19 Hot work tool Steels Composition and PropertiesHot work tool Steels Hot work tool Steels Composition and PropertiesComposition and PropertiesAI SI GRADE NAME C Cr Mo V W OTHER WEAR RESI STANCE TOUGHNESS HOT* HARDNESS HEAT CHECK RESI STANCE 4150 MOD.

10 HOLDER BLOCK P20 CSM 2 KAPSTAR Ni 4. 00, Al H10 MOD. WR95 Co 2. 00 H11 HALCOMB 218 H12 CHRO- MOW H13 NU- DI E V H13 PQ NU- DI E XL S 0. 003 MAX. H13 PQ PDCQ S 0. 003 MAX. H13 MOD. CPM NU- DI E EZ S 0. 17 H13 MOD. CRU 161 H19 HALCOMB 425 Co 4. 20 H21 PEERLESS A CPM 1V CPM 9V June 19, 2004 HABA20 AISI GRADE NAME C Cr Mo V W Co S WEAR RESISTANCE TOUGHNESS RED HARDNESS M1 REX TMO - - M2 REX M2 (S) - ( ) M2 REX M2 HCHS - M3 REX M3-1 - - M4 REX M4 - - M4 CPM M4 HC(HS) - ( ) M7 REX M7N - - M35 CPM REX M35 HCHS M42 REX M42 T4 REX AAA T8 REX 95 T15 CPM T15 (HS) ( ) M62 CPM REX 20 (S) - ( ) M3+Co CPM REX 45(HS) ( ) M4+Co CPM REX 54 (HS) ( ) M48 CPM REX 76(HS) ( ) CPM REX 121 (HS) ( ) AISI GRADE NAME C Cr Mo V W Co S WEAR RESISTANCE TOUGHNESS RED HARDNESS M1 REX TMO - - M2 REX M2 (S) - ( ) M2 REX M2 HCHS - M3 REX M3-1 - - M4 REX M4 - - M4 CPM M4 HC(HS) - ( )