APPLICATION GUIDE Heat resistant super alloys INDONESIA MALAYSIA PHILIPPINES Jakarta: Petaling Jaya: Manila: P.T. SANDVIK INDONESIA SANDVIK MALAYSIA SDN BHD. SANDVIK PHILIPPINES INC. Mugi Griya Building A-5-2. Jaya One. Km 20 East Service Road 3rd Floor 72A, Jalan Universiti, South Superhighway Jl. MT. Haryono Kav. 10 46200 Petaling Jaya, MUNTINLUPA CITY 1770 JAKARTA 12810 Selangor Darul Ehsan. Tel: 63–2-807 6372 to 82 Tel: 62-21 831 4141/2 Malaysia. Fax: 63–2-807 6383 Fax: 62-21 830 8573 Tel: 60 3 7947 7688 (Hotline) E-mail: [email protected] Tel Toll Free: 0-800-1-C O R O - I D 60 3 7947 7777 (0-800-1-2 6 7 6 - 4 3) Fax: 60 3 7947 7766 VIETNAM Fax Toll Free: 0-800-1-7 0 0 - 8 0 0 E-mail: [email protected] Ho Chi Min City: E-mail: [email protected] Representative Office of Sandvik THAILAND South East Asia Pte Ltd SINGAPORE Bangkok: 5th Floor, Sandvik South East Asia SANDVIK THAILAND LTD Vietnam Economic Times Building PTE Ltd 4th Floor Chamnan Phenjati 1/1 Hoang Viet Street, Ward 4, 50 ALPS AVE. Business Center Bldg, 65/48 Tan Binh District, Ho Chi Minh City, #04-00, Sandvik Building Rama 9 Rd., Huay-Kwang Vietnam. SINGAPORE 498782. BANGKOK 10310 Tel: 84-8-3948 4138 (Hunting line) Tel: 65–6477 3786 Tel: 66–2–643 8120 84-8-3948 4139 / 149 / 159 Fax: 65–6477 3783 Fax: 66–2–614 3111 to 3 Fax: 84-8-3948 4129 E-mail: [email protected] E-mail: [email protected] E-mail: [email protected] www.sandvik.coromant.com C-2920:034 ENG/03 © AB Sandvik Coromant 2010.08 This folder is printed on recycleable paper. Printed in Sweden at Sandvikens Tryckeri High pressure coolant machining for better productivity and results More information Useful information and application techniques can be found in our catalogues, handbooks and application guides, such as PluraGuide. CoroGuide web is an internet-based catalogue including a cutting data module (also available on CD) where you can find cutting data recommendations for your specific application. Visit our websites for the latest news! www.sandvik.coromant.com www.aero-knowledge.com Acknowledgement Some sections of this article present the findings of technical investigations carried out by the AMRC* which are sponsored by Sandvik Coromant. * The Advanced Manufacturing Research Centre (AMRC) is a partnership which builds on the shared scientific excellence, expertise and technological innovation of industrial partners and world-class research within the University of Sheffield’s Faculty of Engineering. Contents Introduction 2 4. Milling 60 Production planning process 61 1. Heat resistant super alloys – HRSA 3 Typical components 61 Alloy groups 4 Machining strategy 62 Machinability/raw material condition 5 Cutter concept 64 Common component types 7 Milling process with indexable inserts 65 Coolant requirement 8 Face milling with carbide inserts 68 End milling/90 degree approach 77 2. Turning of nickel-based materials 9 Ceramic milling 82 Machining stages 9 Solid carbide – CoroMill Plura in Typical wear mechanisms 11 HRSA machining 88 Insert shape selection 13 Exchangeable-head CoroMill 316 Cutting tool materials 21 in HRSA machining 97 Ceramic insert grades 22 Component/feature based solutions 98 Carbide insert grades 26 Recommended start cutting data 102 SCL – predictive machining 28 5. Hole making 104 Geometries and chip breaking 31 Hole types and hole making methods 104 Recommended starting choices 34 Tools for hole making 106 Tailor Made 36 Circular ramping from solid 107 Engineered solutions 37 Circular interpolation of existing holes 108 Component/feature solutions 42 Back chamfering/deburring 109 3. Turning of cobalt-based materials 51 Thread milling 110 Process considerations 52 Recommended start cutting data 112 Typical wear recommendations 53 Component/feature solutions 114 Insert shape selection 54 6. Technical data 118 Optimized tools for internal machining 55 Recommended starting choices 57 7. Material cross-reference list 120 Carbide insert grades 58 Engineered solution 58 Component/feature solutions 59 Introduction This application guide concentrates on opti- Productivity along with quality and reliability mizing machining of heat resistant super are our focus. When we talk about produc- alloys (HRSA). tivity you will see that we measure this in For one of the most challenging material terms of cm3/min. It is important to under- groups to machine, optimized tools are nat- stand the relationship between the combi- urally a prerequisite, but equally important nation of speed, feed and depth of cut and is how to apply them. not just cutting speed alone which is often the most damaging parameter when consid- We will guide you through the most com- ering tool life. mon materials and machining applications. We aim to give you application and process recommendations that will help you use our products in the most productive manner with maximum process reliability and com- ponent quality. Our goal is to support customers with complete tooling solutions that meet cost reduction and quality improvment initiatives. 2 1. Heat resistant super alloys – HRSA Heat resistant super alloys (HRSA) are a family of alloys utilised in various industry segments: Aerospace engine – combustion and turbine sections. Stationary gas turbines – combustion and turbine sections. Oil and gas – marine applications. Medical – joint implants. The properties which make them attractive are: • Retension of strength and hardness at high temperatures. • Corrosion resistance. Aerospace engine Stationary gas tur- Oil and gas Medical bines 3 Alloy groups HRSA materials fall into three groups: However, they have the poorest hot strength nickel-based, iron-based and cobalt-based properties of the three groups. alloys. The physical properties and machin- Common types: ing behaviour of each varies considerably, • Inconel 909 due both to the chemical nature of the alloy and the precise metallurgical processing it • A286 receives during manufacture. Whether the • Greek Ascoloy metal is annealed or aged is particularly Cobalt-based display superior hot corrosion influential on the subsequent machining resistance at high temperatures compared properties. to nickel-based alloys. They are more expen- sive and also more difficult to machine due Nickel-based are the most widely used, and to their great wearability. currently constitute over 50% of the weight of advanced aircraft engines. The trend is The use in turbines is restricted to combus- that this will increase in new engines in the tion parts in the hottest engine areas. future. Their main use is seen in surgical implants, Common types include: which utilise their inherent corrosion resist- ance. • Inconel 718, Waspaloy, Udimet 720 – precipitation hardened Common types: • Inconel 625 – solution strengthened • CoCr (not hardenable) • Haynes 25 Iron-based have been developed from • Stellite 31 austenitic stainless steels. Some have very low thermal expansion coefficients (such as Incoloy 909) which make them especially suited for shafts, rings, and casings. The most common HRSA alloys (see page 120 for the complete list) Alloy Code Material Hardness HB group Ann. Aged Nickel MC S2.0.Z.AN CMC 20.2 Inconell 718 425 Inconell 706 285 Inconell 625 200 Hastelloy S Hastelloy X 160 Nimonic PK33 350 Udimet 720 Waspaloy Iron MC P5.0.Z.AN CMC 05.3 Greek Ascoloy 300 MC M1.0.Z.PH CMC 05.4 A286 300 MC S2.0.Z.AN CMC 20.21 Incoloy 909 Cobalt MC S3.0.Z.AG CMC 20.3 Haynes 25 Stellite 21 280 340 Stellite 31 4 With such a wide spread of materials under the generic heading of HRSA the machining behaviour can vary greatly even within the same alloy group. In fact the same material can have numerous machining recommendations. Heat generated during cutting (tendency for plastic deformation) Hardness = Stainless steel HB Nimonic 1023 = Heat treated (aged) Inconel 718 400 Nimonic 80A = Solution Nimonic PK 33 treated Incoloy 901 Waspaloy (annealed) Nimonic 90 Nimonic 105 300 17-4 PH Tendency for notch wear Nimonic 263 Crucible Jethete A286 M152 200 Incoloy 901 Precipitation hard enable alloys in annealed conditions Nimonic 75 Austenitics Incoloy 800 Inconel 625 Sanicro 30 100 Stainless Fe based alloys Ni based alloys steels Weight % 10 20 30 40 50 60 70 80 90 Nickel & cobolt Machinability/raw material condition Heat treatment Annealing – heating to controlled temperature then cooling at <30HRC controlled rate. Solution treatment – heating followed by rapid cooling <30HRC Ageing – slow cooling after solution treatment up to 48HRC The state of heat treatment affects the Softer materials machine similarly to the hardness of the component and hence the stainless steel family. wear mechanisms. The formation of the Insert grades with greater toughness and chip is a good indicator of the hardness – reduced hot hardness – resistance to high with hard materials it is easier to break the temperatures – are required due to reduced chip. cutting temperatures and increased chip Hardened materials have increased cut- hammering. Here, damage to areas outside ting temperatures and show a tendency to the actual cutting edge is caused by the notching of the cutting edge at the depth chip breaking against the insert. of cut. The combination of a low entering angle and a hard substrate with a coating offering a heat barrier is required. 5 Comparison of wear depending upon material hardness and insert grade CNMX 1204A1-SM – v 50 m/min, f 0.25 mm/r, a 1.5 mm c n p Hard material Soft material GC1105 S05F GC1105 S05F 6 min 12 min 7 min 3.5 min Chip hammering Raw material production method Depending upon the size, shape and The production method varies the machina- strength requirements of the component, bility of the material and will change the various production methods for the blank wear characteristics. material will be adopted. Material Components Advantage/suitability Machinability Forging large high strength medium Casting complex shape low strength poor Bar stock <200 mm diameter availability/strength good Each of these raw material types directly most sensitive to notch wear and abrasive affects the alloy’s micro structure, and so wear. They can be easily identified due to also affects the subsequent machining their visibly mottled surface (the ‘orange behaviour: peel’ effect). Forged materials have a finer grain size Bar stock material is the easiest form of than in castings, which improves the raw material to deal with. Notching is not strength and grain flow of the component. so much of a problem, which allows harder When machining forgings, reducing the and more wear resistant insert grades to speed and increasing the feed generally be used than for forgings. gives the maximum possible metal removal rate with good tool life. In castings the opposite applies, and apply- ing low feeds (0.1 mm chip thickness) and higher speeds can be beneficial. Castings have poor machinability and tend to be 6 Common component types Typical HRSA components, and an indication of the different machining methods involved for each include: Aerospace and gas turbine – nickel based Component Turning Milling Drilling Others Discs 60% 10% 5% 25% Casings 45% 40% 15% Rings 95% 5% Blades 10% 50% 40% Blisks Impellers Shafts 70% 5% 25% Medical – CoCr Component Turning Milling Drilling Others Cup 90% 10% Head 90% 10% 7 Coolant requirements Coolant should be applied in all operations excluding milling with ceramics. The volume should be high and well directed. High pressure coolant HPC (up to 80 bar) shows positive results in terms of tool life and consistency. Dedicated HPC-tools with fixed nozzles give HPC improves the chip control parallel laminar jets of coolant with high CNGG 120408-SGF velocity accurately directed at the right zone vc 65 m/min, ap 1.0 mm, fn 0.2 mm/r between insert and chip. Inconel 718 For milling and drilling, all tools with internal coolant supply can benefit from HPC even if tools prepared for nozzles give higher pos- sibility to use smaller nozzle diameters for high pressure. CoroTurn HP tool, 80 bar Conventional tool • Turning, use at least 20 l/min and a Compared chips made with a CoroTurn HP tool versus a basic pressure of 70 bar. conventional tool and standard coolant pressure. • Milling and drilling, use at least 50 l/min to accomodate the extra nozzles on the milling cutter and the largest drill diam- eters. Flow required for specified nozzle diameter and 80 bar high pressure pump The pressure (p) hitting the cutting zone is dependent on the number Flow, ν Nozzle diameter, d of nozzles, the nozzle diameter litres/min (d) and the flow (ν) given from the ∅ 0.5 mm pump. 100 ∅ 1.0 mm 90 ∅ 1.5 mm ∅ 2.0 mm A higher flow rate is needed for 80 ∅ 2.5 mm tools with many outlets or large 70 ∅ 3.0 mm ∅ 3.5 mm hole diameter for the coolant. 60 50 40 30 20 10 0 1 5 10 15 20 25 30 Number of nozzles 8