WELDING OF UDDEHOLM TOOL STEELS

TREATMENT WELDING OF TOOL STEEL 1 © UDDEHOLMS AB No part of this publication may be reproduced or transmitted for commercial purposes without permission of the copyright holder.

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.

Classified according to EU Directive 1999/45/EC For further information see our “Material Safety Data Sheets”.

Edition 7, 10.2017

2 TREATMENT WELDING OF TOOL STEEL CONTENTS

General information on welding of tool steel ...... 4 Welding methods for tool steel ...... 4 The welding bay ...... 6 Filler material ...... 7 Hydrogen in tool steel ...... 8 Elevated working temperature ...... 9 Welding procedure ...... 10 Heat treatment after welding ...... 11 Guidelines for welding in – hot work tool steel ...... 13 – cold work tool steel ...... 14 – plastic mould steel ...... 17

TREATMENT WELDING OF TOOL STEEL 3 GENERAL WELDING deposit is inhibited partly by slag formed from constituents in the elec- INFORMATION METHODS FOR trode coating and partly by gases ON WELDING OF TOOL STEEL created during melting of the elec- trode. TOOL STEEL SHIELDED METAL-ARC The composition of the deposited Tool steel contain up to 2.5% carbon WELDING (SMAW OR MMA) weld metal is controlled via the constitu- as well as alloying elements such as tion of the electrode coating. manganese, chromium, molybdenum, PRINCIPLE tungsten, vanadium and nickel. The An electric arc generated by a DC or POWER SOURCE AC power source is struck between main problem in welding tool steel For MMA welding, it is possible to a coated, rod-like electrode and the stems from its high hardenability. use either an AC or DC power source. work-piece (Fig. 1). Welds cool quickly once the heat However, whichever is used, the The electrodes consist of a central source is removed and the weld metal source must provide a voltage and wire core, which is usually low-carbon and part of the heat-affected zone will current which is compatible with the steel, covered with a coating of harden. This transformation generates electrode. Normal arc voltages are: pressed powder (flux). The constitu- stresses because the weld is normally • normal recovery electrodes: tion of this coating is complex and highly constrained, with a concomi- 20–30 V consists of iron powder, powdered tant risk for cracking unless great • high recovery electrodes: ferro-alloys, slag formers and a care is exercised. 30–50 V In what follows, a description is giv- suitable binder. The electrode is en of the welding equipment, welding consumed under the action of the arc Uddeholm welding consumables are technique and weld consumables during welding and drops of molten of normal recovery type. A suitable that are required in order to weld tool metal are transferred to the work- power source for these is a DC unit with steel successfully. Of course, the skill piece. Contamination by air during an open voltage of 70 V and which is and experience of the welder is also the transfer of molten drops from capable of delivering 250A/30V at 35% a vital ingredient in obtaining satis- electrode to workpiece and during intermittence. factory results. With sufficient care, it solidification and cooling of the weld is possible to achieve weld repairs or adjustments which, in terms of tooling performance, are hardly inferior to that of the base steel. Welding of tooling may be required for anyone of the following reasons: • refurbishment and repair of cracked or worn tooling • renovation of chipped or worn cutting edges, e.g. on blanking tools • adjustment of machining errors in tool making • design changes

4 TREATMENT WELDING OF TOOL STEEL GAS TUNGSTEN-ARC Current is conducted to the electrode LASER WELDING WELDING (GTAW OR TIG) via a contact inside the TIG-gun. Any consumables which are required PRINCIPLE PRINCIPLE during TIG-welding are fed obliquely High power laser light is generated In MMA welding, the electrode from into the arc in the form of rod or wire. and focused through a lens to the which the arc is struck is consumed Oxidation of the weld pool is pre- welding spot. As filler material a thin during welding. vented by an inert-gas shroud which wire with a diameter between 0.1– The electrode in TIG welding is streams from the TIG gun over the 0.6 mm is primarily used. The welder made of tungsten or tungsten alloy electrode and weld. guides the wire to the area to be welded. which has a very high melting point The laser beam melt the wire and the (about 3300°C/6000°F) and is there- POWER SOURCE base material. The molten material fore not consumed during the process TIG welding can be performed with a solidifies leaving behind a small raised (Fig. 2). The arc is initially struck by regular MMA power source provided area. The welder continues spot by spot subjecting the electrode-workpiece this is complemented with a TIG and line by line. An Argon gas at higher gas to a high-frequency voltage. The control unit. A water cooled gun is purity than used at TIG-welding should resulting ionization permits striking normally not necessary as the actual be used to shields the process from without the necessity for contact welding time is very limited. A gas oxidation (Fig. 3). between electrode and workpiece. lens is also a desirable feature in The tungsten electrode is always con- order that the inert gas protection nected to the negative terminal is as efficient as possible. Welding of a DC power source because this is facilitated if the current can be minimizes heat generation and increased steplessly from zero to the thereby any risk of melting the electrode. optimum level.

Core wire Electrode holder

Electrode holder

+ Pole Cooling water Power source Coating – Pole

Slag Protective gas Tungsten electrode – Pole Weld Filler material Power source Melt pool + Pole

Fig. 1 Shielded Metal-Arc Welding SMAW (MMA)

Fig. 2 Gas Tungsten Arc Welding GTAW (TIG)

Protective gas Protective glass

Laser beam

Deposited material Filler wire Fusion zone

Workpiece Fig. 3 Laser Welding

TREATMENT WELDING OF TOOL STEEL 5 POWER SOURCE be equipped with a dry cabinet for be positioned securely and accu- For deposition welding normally a storage of electrodes. This should rately. It is advantageous if the work- pulsed solid state laser of Nd: YAG be thermostatically controlled in the bench is rotatable and adjustable type is used. range 50–150°C (120–300°F). The vertically, since both these features electrodes should be removed from facilitate the welding operation. Typical performance: their containers and lie loose on racks. Nominal output 150–200 W For welding of tooling outside the Max pulse output 10–12 kW PREHEATING EQUIPMENT Pulse time 0.5–20 ms welding bay, it will also be found useful Tool steel cannot be welded at room Frequence 0.5–20 Hz to have a portable heated container in temperature without considerable Spot diameter 0.5–2.0 mm (0.1–0.5 mm) which the electrodes can be carried. risk for cracking and it is generally necessary to pre-heat the mould or WORKBENCH die before any welding can be THE WELDING BAY It is particularly important during attempted (see later). While it is critical welding operations, of the type certainly possible to weld tools In order to be able to effect satis- performed with tool steel, that the successfully by preheating in a factory welding work on tool steel, welder enjoys a comfortable work- furnace, the chances are that the the following items of equipment are ing position. Hence, the workbench temperature will fall excess ively prior to be regarded as minimum require- should be stable, of the correct height to completion of the work. Hence, ments. a sufficiently level that the work can it is recommended that the tool be main-tained at the correct tempera- DRY CABINET ture using an electrical heating box The coated electrodes used for MMA supplied from a current-regulated DC welding are strongly hygroscopic source. This equipment also enables and should not be allowed to come the tool to be heated at a uniform and into contact with anything other than controlled rate. To place the tool on dry air. Otherwise, the weld will be a heated table or plate could some- contaminated with hydrogen (see times be sufficient to maintain the later). Hence, the welding bay should temperature. Electrical elements for an insulated For minor repairs and adjustments, it preheating box. is acceptable that the tool is pre-heated using a propane torch. Hence, liquid propane cylinders should be available in the welding bay.

GRINDING MACHINES The following should be available: • disc grinder with a suitable wheel for preparing the joint and grinding out of any defects which may occur during welding. Wheel dimension depends on defect size, which has to be grinded. • flat grinder capable of ≥25 000 rpm for grinding of minor defects and of the finished weld • if a welded mould is subsequently to be polished or photo-etched, it may be necessary to have a grinder capable of giving a sufficiently fine finish

Preheating in an insulated box. • small rotating metal files in different shapes and sizes

6 TREATMENT WELDING OF TOOL STEEL FILLER MATERIAL Filler rods are normally produced For the three main application from electroslag remelted stock. The segments for tool steel (cold work, The chemical composition of a weld coated electrodes are of basic type, hot work and plastic moulding), the deposit is determined by the compo- which are far superior to rutile elec- important weld-metal properties are: sition of the consumable (filler metal), trodes as regards weld cleanliness. COLD WORK the base steel composition and the Another advantage with basic coated • Hardness extent to which the base material is electrodes over those of rutile type • Toughness melted during welding. The consum- is that the former give a much lower • Wear resistance able electrode or wire should mix hydrogen content in the weld metal. easily with the molten base steel In general, the consumable used HOT WORK giving a deposit with: for welding tool steel should be • Hardness • uniform composition, hardness and similar in composition to the base • Temper resistance response to heat-treatment material. When welding in the an- • Toughness • freedom from non-metallic nealed condition, e.g. if a mould or • Wear resistance inclusions, porosity or cracks die has to be adjusted while in the • Heat checking resistance • suitable properties for the tooling process of manufacture, it is vital that PLASTIC MOULDING application in question the filler metal has the same heat treatment characteristics as the base • Hardness Since tool steel welds have high steel, otherwise the welded area in • Wear resistance hardness, they are particularly the finished tool will have different • Polishability susceptible to cracking which may hardness. Large compositional • Photoetchability originate at slag particles or pores. differences are also associated with Hence, the consumable used should an increased cracking risk in connec- be capable of producing a high- tion with hardening. UDDEHOLM WELDING quality weld. In a similar vein, it is Uddeholm welding consumable are CONSUMABLES necessary that the consumables are designed to be compatible with the produced with very tight analysis UDDEHOLM COATED corresponding tool steel grades control in order that the hardness ELECTRODES irrespective of whether welding is as welded and the response to heat Impax Weld carried out on annealed or hardened treatment is reproducible from batch QRO 90 Weld and tempered base material. to batch. High-quality filler metals Calmax/Carmo Weld Obviously, the weld metal of welded are also essential if a mould is to be tools will require different properties for polished or photo-etched after weld- UDDEHOLM TIG-RODS different applications. ing. Uddeholm welding consumables Impax TIG-Weld meet these requirements. Stavax TIG-Weld Corrax TIG-Weld Nimax TIG-Weld Mirrax TIG-Weld Unimax TIG-Weld QRO 90 TIG-Weld Dievar TIG-Weld Calmax/Carmo TIG-Weld Caldie TIG-Weld

UDDEHOLM LASER RODS Stavax Laser Weld Nimax Laser Weld Dievar Laser Weld

Laser welding consumables from Uddeholm.

TREATMENT WELDING OF TOOL STEEL 7 HYDROGEN In general, the stress level in the in the vicinity of the joint should be vicinity of the weld will reach the mag- ground to bare metal immediately IN TOOL STEEL nitude of the yield stress, which for prior to starting to weld. Welds in tool steel have high hard- hardened tool steel is very high • If preheating is performed with a ness and are, therefore, especially indeed. It is very difficult to do propane burner, it should be susceptible to cold cracking derived anything about this but the situa- remembered that this can cause from hydrogen ingress during weld- tion can be improved somewhat via moisture to form on the tool sur- ing. In many cases, hydrogen is proper weld design, (bead location faces not directly impinged by the generated as a result of water vapour and sequence of runs). However, no flame. being adsorbed in the hygro-scopic measures to reduce stress will help if coating of MMA electrodes. the weld is seriously contaminated by hydrogen. The susceptibility of a weld to hydrogen cracking depends on: • the microstructure of the weld CONTENT OF metal (different microstructures DIFFUSIBLE HYDROGEN have different hydrogen sensi- As regards the susceptibility of welds tivities) to cold cracking, this is the factor that • the hardness of the steel (the it is easiest to do something about. greater the hardness, the higher By adhering to a number of simple the susceptibility) precautions, the amount of hydrogen • the stress level introduced during welding can be • the amount of diffusible hydrogen reduced ap preciably. introduced in welding • Always store coated electrodes in a wheated storage cabinet or heated MICROSTRUCTURE/ container once the pack has been HARDNESS opened (see earlier). The characteristic microstructures • Contamination on the surfaces of giving high hardness in the heat- the joint of the surrounding tool affected zone and weld metal, i.e. surface, e.g. oil, rust or paint, is a martensite and bainite, are particu- source of hydrogen. Hence, the larly sensitive to embrittlement by surfaces of the joint and of the tool hydrogen. This susceptibility is, albeit only marginally, alleviated by tem- pering.

STRESS LEVEL Stresses in welds arise from three sources: • contraction during solidification of the molten pool • temperature differences between weld, heat-affected zone and base steel • transformation stresses when the weld and heat-affected zone harden during cooling

Dry cabinet for storage of electrodes.

8 TREATMENT WELDING OF TOOL STEEL ELEVATED pre-heating temperature will give a very small, but still existing risk of WORKING cracking. The hardness drop must be TEMPERATURE accepted in order to perform a proper preheating and mitigate the risk of The basic reason for welding tool cracking during welding. steel at elev ated temperature During multi-run welding of a pro- derives from the high hardenability perly pre-heated tool, most of the and therefore crack sensitivity of tool weld will remain austenitic under steel welds and heat-affected zones. the entire welding operation and will Welding of a cold tool will cause transform slowly as the tool cools rapid cooling of the weld metal and down. This ensures a uniform hard- heat-affected zone between passes ness and microstructure over the with resulting transformation to whole weld in comparison with the brittle martensite and risk of cracking. situation where each run transforms Cracks formed in the weld could well to martensite in between passes. propagate through the entire tool. It will be clear from this discus- Hence, the mould or die should, sion that the entire welding operation during welding, be maintained at should be completed while the tool 50–100°C (90–180°F) above the M -tem- s is hot. Partially welding, letting the perature (martensite-start temperature) tool cool down and then preheating for the steel in question. The critical later on to finish the job, is not to be temperature is the M of the weld metal, s recommended because there is con- which may not be the same as that of siderable risk that the tool will crack. the base metal. While it is feasible to pre-heat tools in In some instances, it may be that a furnace, there is the possibility that the the base steel is fully hardened and temperature is uneven (creates stresses) has been tempered at a temperature and that it will drop excessively before below the M -temperature. Hence, s welding is completed (especially if the pre-heating the tool for welding will tool is small). cause a drop in hardness. For exam- The best method, of preheating and ple, most low-temperature tempered maintaining the tool at the requested cold work steel will have to be pre- temperature during welding, is to use heated to a temperature in excess of an insulated box with electrical the tempering temperature, which is elements in the walls (see page 6). usually ca. 200°C (400°F). This low

A highly polished mould for production of car headlights.

TREATMENT WELDING OF TOOL STEEL 9 WELDING During MMA welding, the arc should be short and the beads deposited in PROCEDURE distinct runs. The electrode should be BUILD UP SEQUENCE JOINT PREPARATION angled at 90° to the joint sides so as to minimize undercut. In addition, the The importance of careful preparation electrode should be held at an angle can not be over-emphasized. Cracks of 75–80°C to the direction of forward should be ground out so that the movement. Undercut Sink run groove angle will be 60° if possible. The arc should be struck in the joint The width of the bottom should be at and not on any tool surfaces which are least 1 mm greater than the maximum not being welded. The sore form striking electrode diameter which will be the arc is likely location for crack initia- used. tion. In order to avoid pores, the starting Erosion or heat-checking damage on sore should be melted up completely at hot work tools should be ground down the beginning of welding. If a restart is to sound steel. made with a partly-used MMA electrode, The tool surfaces in the immediate the tip should be cleaned free from slag. vicinity of the intended weld and the For repair or adjustment of expen- surfaces of the groove itself must all sive tooling, e.g. plastic mould with be ground down to clean metal. Prior a polished or textured cavity, it is to starting welding, the ground areas essential that there is good contact should be checked with penetrant between the return cable and the tool. to make sure all defects have been Poor contact gives problems with removed. The tool should be welded secondary arcing and the expensive as soon as the preparation is finished, surface can be damaged by arcing otherwise there is risk of contamina- sores. Such tools should be placed tion of the surfaces with dust, dirt or on a copper plate which provides for Undercut moisture. the best possible contact. The copper plate must be preheated along with Sink run BUILDING UP THE WELD the tool. To avoid undercut in the border line, The completed weld(s) should be between the weld and the base carefully cleaned and inspected prior to material, start with fine sink runs. The allowing the tool to cool down. initial layer should be made with a Any defect, such as arcing sores small diameter MMA electrode, or undercut, should be dealt with 2,5 mm, or via TIG welding (max. current immedately. 90 A). Before the tool has cooled, the surface The second layer is made with the of the weld should be ground down same electrode diameter and current almost to the level of the surrounding GROOVE as the first in order to minimize the tool before any further processing. PREPARATION heat-affected zone. The remaining Moulds where welded areas have to of the groove can be welded with a be polished or photo-etched should higher current and electrodes with have the final runs made using TIG- larger diameter. welding, which is less likely to give pores Crack risk OK The final runs should be built up well or inclusions in the weld metal. above the surface of the tool. Even small welds should comprise a minimum of two runs. Grind off the last runs. Remove cracks Clean surface

10 TREATMENT WELDING OF TOOL STEEL HEAT TREATMENT holm QRO 90 Weld); in this case, the cycle used is that recommended for weld should be tempered at the high- the base steel. The welded area can AFTER WELDING est possible temperature concomitant then be machined and the tool may Depending on the initial condition with the base steel retaining its hard- be finished and heat treated as usual. of the tool, the following heat ness (typically 20°C/40°F under the However, even if the tool can be treatments may be performed after previous tempering temperature). finished by merely grinding the weld, welding: Product brochures for Uddeholm soft annealing is first recommended • tempering welding consumables and tool steels in order to mitigate cracking during • soft annealing, then hardening give tempering curves from which the heat treatment. and tempering as usual tempering conditions for welded tools • stress relieving can be ascertained. STRESS RELIEVING Very small repairs may not need to be Stress relieving is sometimes carried TEMPERING tempered after welding; however, this out after welding in order to reduce should be done if at all possible. Fully-hardened tools which are repair residual stresses. For very large or welded are recommended to be highly-constrained welds, this is an tempered after welding. important precaution. If the weld is to Tempering improves the tough- SOFT ANNEALING be tempered or soft annealed, then ness of the weld metal and the heat Tools which are welded to accom- stress relieving is not normally neces- affected zone (HAZ). modate design changes or machining sary. However, pre-hardened tool The tempering temperature should errors during toolmaking, and which steel should be stress relieved after be chosen so that the hardness of the are in soft-annealed condition, will welding since no other heat treatment weld metal and base steel are com- need to be heat treated after weld- is normally performed. patible. An exception to this rule is ing. Since the weld metal and HAZ The stress relieving temperature must when the weld metal exhibits appreci- will have hardened during cooling, it be chosen such that neither the base ably improved temper resistance over is highly desirable to soft anneal the steel nor the welded area soften exten- the base material (e.g. Uddeholm weld prior to hardening and temper- sively during the oper ation. Orvar Supreme welded with Udde- ing of the tool. The soft annealing Very small weld repairs or adjustments will normally not require a stress reliev- ing treatment.

FURTHER INFORMATION Information concerning heat treat- ment of the tool subsequent to welding can be obtained from the brochures for the welding consum- able and/or the tool steel in question.

Heat treatment of a die-casting die after welding.

TREATMENT WELDING OF TOOL STEEL 11 12 TREATMENT WELDING OF TOOL STEEL GUIDELINES FOR WELDING IN UDDEHOLM TOOL STEEL

The tables, on following pages, give details concerning weld repair or adjustment of tooling made from Uddeholm steel grades for hot work, cold work and plastic moulding applications.

WELDING IN HOT WORK TOOL STEEL – MMA (SMAW)

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

VIDAR SUPERIOR VIDAR 1 Soft annealed MMA QRO 90 WELD Min. 48–53 HRC Soft annealing VIDAR 1 ESR Hardened (SMAW) UTP 673 325°C (620°F) 55–58 HRC Tempering

ORVAR SUPREME ORVAR SUPERIOR ORVAR 2 Soft annealed MMA QRO 90 WELD Min. 48–53 HRC Soft annealing MICRODIZED Hardened (SMAW) UTP 673 325°C (620°F) 55–58 HRC Tempering

Soft annealed MMA Min. Soft annealing Soft annealing, see DIEVAR Hardened (SMAW) QRO 90 WELD 325°C (620°F) 48–53 HRC Tempering product brochure Temper hardened QRO 90 material 10–20°C SUPREME Soft annealed MMA Soft annealing (20–40°F) below last HOTVAR Hardened (SMAW) QRO 90 WELD 325°C (620°F) 48–53 HRC Tempering tempering temperature

Tempering MMA 225–275°C at 550°C Stress relieve large ALVAR 14 Prehardened (SMAW) UTP 73 G4 (430–520°F) 38–42 HRC (1020°F) repairs

WELDING IN HOT WORK TOOL STEEL – TIG (GTAW)

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

VIDAR SUPERIOR VIDAR 1 Soft annealed TIG QRO 90 TIG WELD Min. Soft annealing VIDAR 1 ESR Hardened (GTAW) DIEVAR TIG WELD 325°C (620°F) 48–53 HRC Tempering

ORVAR SUPREME Soft annealed TIG QRO 90 TIG WELD Min. Soft annealing ORVAR SUPERIOR Hardned (GTAW) DIEVAR TIG WELD 325°C (620°F) 48–53 HRC Tempering ORVAR 2 DIEVAR Temper 250°C MICRODIZED LASER LASER WELD None 48–53 HRC (480°F) 2 h

Soft annealed TIG DIEVAR TIG WELD Min. Soft annealing Hardened (GTAW) QRO 90 TIG WELD 325°C (620°F) 48–53 HRC Tempering Soft annealing, see product brochure DIEVAR Temper 250°C DIEVAR LASER LASER WELD None 48–53 HRC (480°F) 2 h Temper hardened material 10–20°C QRO 90 (20–40°F) below SUPREME Soft annealed TIG Soft annealing lasttempering HOTVAR Hardened (GTAW) QRO 90 TIG WELD 325°C (620°F) 48–53 HRC Tempering temperature

Tempering TIG 225–275°C at 550°C Stress relieve large ALVAR 14 Prehardened (GTAW) UTP A 73 G4 (430–520°F) 38–42 HRC (1020°F) repairs

TREATMENT WELDING OF TOOL STEEL 13 WELDING IN COLD WORK TOOL STEEL – MMA (SMAW)

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

Tempering ARNE Type AWS E312 300 HB 10–20°C RIGOR ESAB OK 84.52 53–54 HRC (20–40°F) VIKING Hardened MMA UTP 67S 200–250°C 55–58 HRC below last Initial layers with FERMO* Prehardened (SMAW) UTP 73 G2 (390–480°F) 55–58 HRC tempering temp. soft weld metal

MMA 200–250°C Tempering at CALDIE* Hardened (SMAW) UTP 673 (390–480°F) 58–62 HRC 510°C (950°F)

Tempering 10–20°C (20–40°F) MMA below last SLEIPNER Hardened (SMAW) UTP 690 250°C (480°F) 60–64 HRC tempering temp.

Tempering UTP 6222 Mo 280 HB 10–20°C UTP 73 G2 55–58 HRC (20–40°F) SVERKER 21 MMA UTP 67S 55–58 HRC below last Initial layers with SVERKER 3 Hardened (SMAW) UTP 690 250°C (480°F) 60–64 HRC tempering temp. soft weld metal

MMA CALMAX/CARMO CARMO* Prehardened (SMAW) WELD 200–250°C (390–480°F) 58–62 HRC Tempering

MMA CALMAX (SMAW) See “Welding guidelines for plastic mould steel”

Tempering 200°C (390°F) or 505°C VANADIS 4 Type Inconel 625 280 HB (940°F) depend- EXTRA MMA UTP 73 G2 200°C 55–58 HRC ing on the last Initial layers with SUPERCLEAN** Hardened (SMAW) UTP 690 (390°F) 60–64 HRC used temp. temp. soft weld metal

* Minor welding operations in Uddeholm Fermo and Uddeholm Carmo can be done at ambient temperature. ** Welding in Uddeholm Vanadis 4 Extra SuperClean should generally be avoided due to the risk of cracking.

14 TREATMENT WELDING OF TOOL STEEL GUIDELINES FOR WELDING IN COLD WORK TOOL STEEL – TIG (GTAW)

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

ARNE Tempering RIGOR Type AWS ER312 300 HB 10–20°C VIKING Hardened TIG UTP ADUR 600 200–250°C 55–58 HRC below last Initial layers with FERMO* Prehardened (GTAW) UTP A 73 G2 (390–480°F) 53–56 HRC tempering temp. soft weld metal

TIG 200–250°C Tempering CALDIE* Hardened (GTAW) CALDIE TIG-WELD (390–480°F) 58–62 HRC 510°C (950°F)

Tempering 10–20°C (20–40°F) TIG CALDIE TIG-WELD 58–62 HRC below last SLEIPNER Hardened (GTAW) UTP A 696 250°C (480°F) 60–64 HRC tempering temp.

Tempering UTP A 6222 Mo 280 HB 10–20°C UTP A 73 G2 53–56 HRC (20–40°F) SVERKER 21 TIG UTP ADUR 600 55–58 HRC below last Initial layers with SVERKER 3 Hardened (GTAW) UTP A 696 250°C (480°F) 60–64 HRC tempering temp. soft weld metal

TIG CALMAX/CARMO CARMO* Prehardened (GTAW) TIG WELD 200–250°C (390–480°F) 58–62 HRC Tempering

TIG CALMAX (GTAW) See “Welding guidelines for plastic mould steel”

Tempering 200°C (390°F) or 505°C VANADIS 4 UTP A 6222 Mo Type Inconel 625 280 HB (940°F) depend- EXTRA TIG UTP A 73 G2 200°C 53–56 HRC ing on the last SUPERCLEAN** Hardened (GTAW) UTP A 696 (390°F) 60–64 HRC used temp. temp.

Tempering 20°C (35°F) below last VANADIS 8 TIG 375°C tempering Initial layers with SUPERCLEAN Hardened (GTAW) UTP A 696 (710°F) 60–64 HRC temperature soft weld metal

* Minor welding operations in Uddeholm Fermo, Uddeholm Caldie and Uddeholm Carmo can be done at ambient temperature. ** Welding in Uddeholm Vanadis 4 Extra SuperClean should generally be avoided due to the risk of cracking.

TREATMENT WELDING OF TOOL STEEL 15 EXAMPLE OF LASER WELDS

16 TREATMENT WELDING OF TOOL STEEL GUIDELINES FOR WELDING IN PLASTIC MOULD STEEL – MMA (SMAW)

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

Stress relieve IMPAX MMA 200–250°C large repairs SUPREME* Prehardened (SMAW) IMPAX WELD (390–480°F) 320–350 HB 550°C (1020°F)

Heat treatment Soft annealed Soft annealing see product brochure MMA UTP 73 G2 200–250°C Tempering UNIMAX Hardened (SMAW) UTP 67 S (390–480°F) 55–58 HRC 510°C (950°F)

Austenitic stainless MMA steel 200–250°C RAMAX HH* Prehardened (SMAW) Type AWS E312 (390–480°F) 28–30 HRC Tempering

200–250°C Soft annealed (390–480°F) Soft annealing

MMA CALMAX/CARMO 180–250°C Heat treatment CALMAX Hardened (SMAW) WELD (360–480°F) 59–62 HRC Tempering see product brochure

Stress relieve MMA 150–200°C large repairs HOLDAX* Prehardened (SMAW) IMPAX WELD (300–390°F) 320–350 HB 550°C (1020°F) Soft annealing, see product brochure. Temper hardened ORVAR Soft annealed Soft annealing material 10–20°C SUPREME MMA Min. (20–40°F) below last VIDAR 1 ESR Hardened (SMAW) UTP 673 325°C (620°F) 55–58 HRC Tempering tempering temperature

MMA 250–300°C 280 HB Tempering ELMAX** Hardened (SMAW) UTP 6222 Mo (480–570°F) 54–57 HRC 200°C (390°F)

* Minor welding operations can be done at ambient temperature. ** Welding should generally be avoided due to the risk of cracking.

TREATMENT WELDING OF TOOL STEEL 17 GUIDELINES FOR WELDING IN PLASTIC MOULD STEEL – TIG (GTAW) AND LASER

UDDEHOLM WELDING PREHEATING HARDNESS POST STEEL GRADE CONDITION METHOD CONSUMABLES TEMPERATURE AS WELDED TREATMENT REMARKS

TIG STAVAX 200–250°C (GTAW) TIG-WELD (390–480°F) 54–56 HRC Soft annealing STAVAX Heat treatment Soft annealed LASER LASER WELD None 48–50 HRC None see product brochure Tempering TIG STAVAX 200–250°C 200–250°C (GTAW) TIG-WELD (390–480°F) 54–56 HRC (390–480°F) STAVAX ESR STAVAX POLMAX Hardened LASER LASER WELD None 48–50 HRC None Annealing 700- 750°C (1290- Sot annealed 1380°F) 5h Tempering 10– 20°C (20–40°F) TIG MIRRAX 200–250°C below last MIRRAX ESR Hardened (GTAW) TIG-WELD (390–480°F) 54–56 HRC tempering temp. TIG MIRRAX 200–250°C Temper 560°C Weld metal hardness MIRRAX 40* Prehardened (GTAW) TIG-WELD (390–480°F) 54–56 HRC (1040°F) 2 h after temp. 38–42 HRC

Stress relieve IMPAX TIG 200–250°C large repairs See data sheet for SUPREME* Prehardened (GTAW) IMPAX TIG-WELD (390–480°F) 320–350 HB 550°C (1020°F) IMPAX TIG-WELD

Stress relieve TIG large repairs (GTAW) NIMAX TIG-WELD NIMAX NIMAX Prehardened LASER LASER WELD None 360–400 HB None

Heat treatment Soft annealed UNIMAX 54–58 HRC Soft annealing see product brochure TIG-WELD TIG UTP A 73 G2 200–250°C Tempering UNIMAX Hardened (GTAW) UTP ADUR 600 (390–480°F) 54–60 HRC 510°C (950°F)

Austenitic stainless steel. TIG Type AWS ER312 200–250°C 28–30 HRC Heat treatment RAMAX HH* Prehardened (GTAW) STAVAX TIG-WELD (390–480°F) 54–56 HRC Tempering see product brochure

Solution treated TIG CORRAX See data sheet for CORRAX Aged (GTAW) TIG-WELD None 30–35 HRC Ageing Corrax TIG-Weld

200–250°C Soft annealed (390–480°F) Soft annealing

TIG CALMAX/CARMO 180–250°C Heat treatment CALMAX Hardened (GTAW) TIG-WELD (360–480°F) 58–61 HRC Tempering see product brochure

Stress relieve TIG 150–200°C large repairs HOLDAX* Prehardened (GTAW) IMPAX TIG-WELD (300–390°F) 320–350 HB 550°C (1020°F)

Soft annealing, see Soft annealed Soft annealing product brochure TIG DIEVAR TIG WELD Min. 48–53 HRC Temper hardened Hardned (GTAW) UTP A673 325°C (620°F) 57–60 HRC Tempering ORVAR material 10–20°C SUPREME DIEVAR Temper 250°C (20–40°F) below last VIDAR 1 ESR LASER LASER WELD None 48–53 HRC (480°F) 2 h tempering temperature

TIG MIRRAX 250–300°C Tempering ELMAX** Hardened (GTAW) TIG-WELD (480–570°F) 54–57 HRC 200°C (390°F)

* Minor welding operations can be done at ambient temperature. ** Welding should generally be avoided due to the risk of cracking.

18 TREATMENT WELDING OF TOOL STEEL NETWORK OF EXCELLENCE Uddeholm is present on every continent. This ensures you high-quality Swedish tool steel and local support wherever you are. Our goal is clear – to be your number one partner and tool steel provider.

TREATMENT WELDING OF TOOL STEEL 19 UDDEHOLM 10.2017.200 / STROKIRK-LANDSTRÖMS, Karlstad

Uddeholm is the world’s leading supplier of tooling materials. This is a position we have reached by improving our customers’ everyday business. Long tradition combined with research and product development equips Uddeholm to solve any tooling problem that may arise. It is a challenging process, but the goal is clear – to be your number one partner and tool steel provider.

Our presence on every continent guarantees you the same high quality wherever you are. We act worldwide. For us it is all a matter of trust – in long-term partnerships as well as in developing new products.

For more information, please visit www.uddeholm.com

20 TREATMENT WELDING OF TOOL STEEL