WELDING OF 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 6, – Revised 02.2014 and 10.2015, not printed The latest revised edition of this brochure is the English version, SS-EN ISO 9001 which is always published on our web site www.uddeholm.com SS-EN ISO 14001 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 Het treatment after welding ...... 11 Guidelines for welding in – hot work tool steel ...... 13 – cold work tool steel ...... 14 – plastic mould steel...... 17

3 WELDING OF TOOL STEEL

General informa- welding technique and weld con- sumables that are required in order Welding methods tion on welding of to weld tool steel successfully. Of for tool steel course, the skill and experience of tool steel the welder is also a vital ingredient in Shielded metal-arc welding To ol steel contain up to 2.5% carbon obtaining satisfactory results. With (SMAW or MMA) as well as alloying elements such as sufficient care, it is possible to , , , achieve weld repairs or adjustments PRINCIPLE tungsten, vanadium and nickel. The which, in terms of tooling perform- An electric arc generated by a DC or main problem in welding tool steel ance, are hardly inferior to that of the AC power source is struck between stems from its high hardenability. base steel. a coated, rod-like electrode and the Welds cool quickly once the heat Welding of tooling may be required work-piece (Fig. 1). source is removed and the weld for anyone of the following reasons: The electrodes consist of a central metal and part of the heat-affected • refurbishment and repair of wire core, which is usually low- zone will harden. This transformation cracked or worn tooling , covered with a coating generates stresses because the weld • renovation of chipped or worn of pressed powder (flux). The consti- is normally highly constrained, with a cutting edges, e.g. on blanking tools tution of this coating is complex and concomitant risk for cracking unless • adjustment of machining errors in consists of iron powder, powdered great care is exercised. tool making ferro-alloys, slag formers and a suit- In what follows, a description is • design changes able binder. The electrode is con- given of the welding equipment, sumed under the action of the arc during welding and drops of molten metal are transferred to the work- piece. Contamination by air during the transfer of molten drops from electrode to workpiece and during solidification and cooling of the weld deposit is inhibited partly by slag formed from constituents in the elec- trode coating and partly by gases created during melting of the elec- trode. The composition of the deposited weld metal is controlled via the con- stitution of the electrode coating.

POWER SOURCE For MMA welding, it is possible to use either an AC or DC power source. However, whichever is used, the source must provide a voltage and current which is compatible with the electrode. Normal arc voltages are: • normal recovery electrodes: 20–30 V • high recovery electrodes: 30–50 V Uddeholm welding consumables are of normal recovery type. A suitable power source for these is a DC unit with an open voltage of 70 V and which is capable of delivering 250A/ 30V at 35% intermittence.

4 WELDING OF TOOL STEEL

Gas tungsten-ARC welding minimizes heat generation and there- inert gas protection is as efficient as by any risk of melting the electrode. possible. Welding is facilitated if the (GTAW or TIG) Current is conducted to the elec- current can be increased steplessly trode via a contact inside the TIG- from zero to the optimum level. PRINCIPLE gun. Any consumables which are In MMA welding, the electrode from required during TIG-welding are fed which the arc is struck is consumed obliquely into the arc in the form of Laser Welding during welding. rod or wire. Oxidation of the weld PRINCIPLE The electrode in TIG welding is pool is prevented by an inert-gas made of tungsten or tungsten alloy shroud which streams from the TIG High power laser light is generated which has a very high melting point gun over the electrode and weld. and focused through a lens to the (about 3300°C/6000°F) and is there- welding spot. As filler material a thin fore not consumed during the proc- wire with a diameter between 0.1– ess (Fig. 2). The arc is initially struck POWER SOURCE 0.6 mm is primarily used. The welder by subjecting the electrode-work- TIG welding can be performed with a guides the wire to the area to be piece gas to a high-frequency voltage. regular MMA power source provided welded. The laser beam melt the The resulting ionization permits strik- this is complemented with a TIG wire and the base material. The mol- ing without the necessity for contact control unit. The gun should be water ten material solidifies leaving behind between electrode and workpiece. cooled and be capable of handling a a small raised area. The welder con- The tungsten electrode is always minimum current of 250 A at 100% tinues spot by spot and line by line. connected to the negative terminal of intermittence. A gas lens is also a Argon gas shields the process from a DC power source because this desirable feature in order that the oxidation (Fig.3).

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

5 WELDING OF TOOL STEEL

POWER SOURCE age of electrodes. This should be work can be positioned securely and For deposition welding normally a thermostatically controlled in the accurately. It is advantageous if the pulsed solid state laser of Nd: YAG range 50–150°C (120–300°F). The workbench is rotatable and adjust- type is used. electrodes should be removed from able vertically, since both these fea- their containers and lie loose on tures facilitate the welding operation. Typical performance: racks. For welding of tooling outside the Nominal output 150–200 W Preheating equipment Max pulse output 10–12 kW welding bay, it will also be found use- Pulse time 0.5–20 ms ful to have a portable heated con- To ol steel cannot be welded at room Frequence 0.5–20 Hz tainer in which the electrodes can be temperature without considerable Spot diameter 0.5–2.0 mm (0.1–0.5 mm) carried. risk for cracking and it is generally necessary to pre-heat the mould or die before any welding can be Workbench attempted (see later). While it is The welding bay It is particularly important during certainly possible to weld tools suc- critical welding operations, of the cessfully by preheating in a furnace, In order to be able to effect satisfac- type performed with tool steel, that the chances are that the temperature tory welding work on tool steel, the the welder enjoys a comfortable will fall excessively prior to comple- following items of equipment are to working position. Hence, the work- tion of the work. Hence, it is recom- be regarded as minimum require- bench should be stable, of the cor- mended that the tool be maintained ments. rect height a sufficiently level that the at the correct temperature using an electrical heating box supplied from a Dry cabinet current-regulated DC source. This The coated electrodes used for MMA equipment also enables the tool to welding are strongly hygroscopic and be heated at a uniform and control- should not be allowed to come into led rate. contact with anything other than dry To place the tool on a heated table air. Otherwise, the weld will be con- or plate could sometimes be suffi- taminated with hydrogen (see later). cient to maintain the temperature. For minor repairs and adjustments, Hence, the welding bay should be Electrical elements for an insulated it is acceptable that the tool is pre- equipped with a dry cabinet for stor- preheating box. 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 minimum 180 Ø x 6 mm wheel (7 Ø x 0,25”) for preparing the joint and grinding out of any defects which may occur during welding •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 • small rotating metal files in different shapes and sizes Preheating in an insulated box.

6 WELDING OF TOOL STEEL

Filler rods are normally produced For the three main application seg- Filler material from electro-slag remelted stock. ments for tool steel (cold work, hot The chemical composition of a weld The coated electrodes are of basic work and plastic moulding), the im- deposit is determined by the compo- type, which are far superior to rutile portant weld-metal properties are: sition of the consumable (filler metal), electrodes as regards weld cleanli- COLD WORK the base steel composition and the ness. Another advantage with basic • Hardness extent to which the base material is coated electrodes over those of •Toughness melted during welding. The consum- rutile type is that the former give a •Wear resistance able electrode or wire should mix much lower hydrogen content in the easily with the molten base steel weld metal. HOT WORK giving a deposit with: In general, the consumable used • Hardness • uniform composition, hardness and for welding tool steel should be simi- •Temper resistance response to heat-treatment lar in composition to the base mate- •Toughness • freedom from non-metallic inclu- rial. When welding in the annealed •Wear resistance sions, porosity or cracks condition, e.g. if a mould or die has • Heat checking resistance • suitable properties for the tooling to be adjusted while in the process PLASTIC MOULDING application in question of manufacture, it is vital that the • Hardness filler metal has the same heat treat- •Wear resistance Since tool steel welds have high hard- ment characteristics as the base •Polishability ness, they are particularly susceptible steel, otherwise the welded area in •Photoetchability to cracking which may originate at the finished tool will have different slag particles or pores. Hence, the hardness. Large compositional differ- consumable used should be capable ences are also associated with an Uddeholm welding of producing a high-quality weld. In a increased cracking risk in connection similar vein, it is necessary that the with hardening. consumables consumables are produced with very Uddeholm welding consumable are UDDEHOLM COATED tight analysis control in order that designed to be compatible with the ELECTRODES the hardness as welded and the corresponding tool steel grades irre- Impax Weld response to heat treatment is repro- spective of whether welding is car- QRO 90 Weld ducible from batch to batch. High- ried out on annealed or hardened- Calmax/Carmo Weld quality filler metals are also essential and tempered base material. Weld if a mould is to be polished or photo- Obviously, the weld metal of etched after welding. Uddeholm welded tools will require different UDDEHOLM TIG-RODS welding consumables meet these properties for different applications. requirements. Impax TIG-Weld 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.

7 WELDING OF TOOL STEEL

Hydrogen of runs). However, no measures to reduce stress will help if the weld is in tool steel seriously contaminated by hydrogen. Welds in tool steel have high hard- ness and are, therefore, especially Content of susceptible to cold cracking derived diffusible hydrogen from hydrogen ingress during weld- As regards the susceptibility of welds ing. In many cases, hydrogen is gener- to cold cracking, this is the factor that ated as a result of water vapour be- it is easiest to do something about. ing adsorbed in the hygro-scopic By adhering to a number of simple coating of MMA electrodes. precautions, the amount of hydrogen The susceptibility of a weld to introduced during welding can be hydrogen cracking depends on: reduced appreciably. • the microstructure of the weld • Always store coated electrodes in a metal (different microstructures heated storage cabinet or heated have different hydrogen sensitivi- container once the pack has been ties) opened (see earlier). • the hardness of the steel (the greater the hardness, the higher the • Contamination on the surfaces of susceptibility) the joint of the surrounding tool • the stress level surface, e.g. oil, rust or paint, is a • the amount of diffusible hydrogen source of hydrogen. Hence, the introduced in welding surfaces of the joint and of the tool in the vicinity of the joint should be ground to bare metal immediately Microstructure/hardness prior to starting to weld. The characteristic microstructures • If preheating is performed with a giving high hardness in the heat- propane burner, it should be affected zone and weld metal, i.e. remembered that this can cause martensite and bainite, are particu- moisture to form on the tool sur- larly sensitive to embrittlement by faces not directly impinged by the hydrogen. This susceptibility is, albeit flame. only marginally, alleviated by temper- ing.

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 In general, the stress level in the vici- nity of the weld will reach the magni- tude of the yield stress, which for hardened tool steel is very high in- deed. It is very difficult to do anything about this but the situation can be improved somewhat via proper weld Dry cabinet for design, (bead location and sequence storage of electrodes.

8 WELDING OF TOOL STEEL

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

Uddeholm Stavax Weld/TIG-Weld and Uddeholm Impax Weld/TIG-Weld match their corresponding tool steel grades exactly and give perfect results after polishing or texturing of a welded mould.

9 WELDING OF TOOL STEEL

Welding procedure The arc should be struck in the joint and not on any tool surfaces which BUILD UP SEQUENCE Joint preparation are not being welded. The sore form striking the arc is likely location for The importance of careful prepara- crack initiation. In order to avoid tion can not be over-emphasized. pores, the starting sore should be Cracks should be ground out so that melted up completely at the begin- the groove angle will be 60° if possi- ning of welding. If a restart is made ble. The width of the bottom should Undercut Sink run with a partly-used MMA electrode, be at least 1 mm greater than the the tip should be cleaned free from maximum electrode diameter which slag. will be used. For repair or adjustment of expen- Erosion or heat-checking damage sive tooling, e.g. plastic mould with a on hot work tools should be ground polished or textured cavity, it is down to sound steel. essential that there is good contact The tool surfaces in the immediate between the return cable and the vicinity of the intended weld and the tool. Poor contact gives problems surfaces of the groove itself must all with secondary arcing and the expen- be ground down to clean metal. Prior sive surface can be damaged by arcing to starting welding, the ground areas sores. Such tools should be placed on should be checked with penetrant to a plate which provides for the make sure all defects have been re- best possible contact. The copper moved. The tool should be welded as plate must be preheated along with soon as the preparation is finished, the tool. otherwise there is risk of contamina- The completed weld(s) should be tion of the surfaces with dust, dirt or carefully cleaned and inspected prior moisture. to allowing the tool to cool down. Any defect, such as arcing sores or Undercut Building up the weld undercut, should be dealt with imme- To avoid undercut in the border line, diately. between the weld and the base mate- Before the tool has cooled, the Sink run rial, start with fine sink runs. The init- surface of the weld should be ground ial layer should be made with a small down almost to the level of the sur- diameter MMA electrode, 2,5 mm, or rounding tool before any further via TIG welding (max. current 120 A). processing. The second layer is made with the Moulds where welded areas have same electrode diameter and current to be polished or photo-etched as the first in order to minimize the should have the final runs made using heat-affected zone. The remaining of TIG-welding, which is less likely to the groove can be welded with a give pores or inclusions in the weld higher current and electrodes with metal. GROOVE PREPARATION larger diameter. The final runs should be built up well above the surface of the tool. Even small welds should comprise a minimum of two runs. Grind off the Crack risk OK last runs. During MMA welding, the arc should be short and the beads de- posited in distinct runs. The elec- Remove cracks Clean surface trode should be angled at 90° to the joint sides so as to minimize under- cut. In addition, the electrode should be held at an angle of 75–80°C to the direction of forward movement.

10 WELDING OF TOOL STEEL

Heat treatment Uddeholm QRO 90 Weld); in this cycle used is that recommended for case, the weld should be tempered at the base steel. The welded area can after welding the highest possible temperature then be machined and the tool may concomitant with the base steel be finished and heat treated as usual. Depending on the initial condition retaining its hardness (typically 20 C/ However, even if the tool can be of the tool, the following heat treat- ° 40 F under the previous tempering finished by merely grinding the weld, ments may be performed after ° temperature). soft annealing is first recommended welding: Product brochures for Uddeholm in order to mitigate cracking during • tempering welding consumables and tool steel heat treatment. • soft annealing, then hardening give tempering curves from which and tempering as usual the tempering conditions for welded • stress relieving Stress relieving tools can be ascertained. Stress relieving is sometimes carried Tempering Very small repairs may not need to be tempered after welding; however, out after welding in order to reduce Fully-hardened tools which are repair this should be done if at all possible. residual stresses. For very large or welded should if possible be tem- highly-constrained welds, this is an pered after welding. important precaution. If the weld is Tempering improves the tough- Soft annealing to be tempered or soft annealed, ness of the weld metal and the heat To ols which are welded to accommo- then stress relieving is not normally affected zone (HAZ). date design changes or machining necessary. However, pre-hardened The tempering temperature should errors during toolmaking, and which tool steel should be stress relieved be chosen so that the hardness of are in soft-annealed condition, will after welding since no other heat the weld metal and base steel are need to be heat treated after welding. treatment is normally performed. compatible. An exception to this rule Since the weld metal and HAZ will The stress relieving temperature is when the weld metal exhibits ap- have hardened during cooling, it is must be chosen such that neither the preciably improved temper resistance highly desirable to soft anneal the base steel nor the welded area soften over the base material (e.g. Udde- weld prior to hardening and temper- extensively during the operation. holm Orvar Supreme welded with ing of the tool. The soft annealing Very small weld repairs or adjust- ments will normally not require a stress relieving 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.

11 WELDING OF TOOL STEEL

12 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

ALVAR MMA UTP 73 G4 225–275°C Stress relieve large ALVAR 14 Prehardened (SMAW) ESAB OK 83.28 (430–520°F) 340–390 HB None 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 Te m p er 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

UTP A 73 G4 ALVAR TIG ESAB OK TIG ROD 225–275°C Stress relieve large ALVAR 14 Prehardened (GTAW) 13.22 (430–520°F) 340–390 HB None repairs

13 WELDING OF TOOL STEEL

GUIDELINES FOR 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°CTempering CALDIE* Hardened (SMAW) CALDIE WELD (390–480°F) 58–62 HRC 510°C (950°F)

Tempering 10–20°C (20–40°F) MMA CALDIE WELD 58–62 HRC below last SLEIPNER Hardened (SMAW) UTP 690 250°C (480°F) 60–64 HRC tempering temp.

Tempering Type Inconel 625 280 HB 10–20°C UTP 73 G2 55–58 HRC (20–40°F) 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”

Te mpering 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, 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.

14 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°CTempering 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 Type Inconel 625 280 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”

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

15 WELDING OF TOOL STEEL

EXAMPLE OF LASER WELDS

16 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°CTempering 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°CHeat 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 Type Inconel 625 250–300°C280 HB Tempering ELMAX** Hardened (SMAW) UTP 701 (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.

17 WELDING OF TOOL STEEL

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 MIRRAX Tempering 10– TIG-WELD 20°C (20–40°F) TIG STAVAX 200–250°Cbelow last MIRRAX ESR Hardened (GTAW) TIG-WELD (390–480°F) 54–56 HRC tempering temp. TIG MIRRAX 200–250°CTemper 560°CWeld 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 450°C (840°F) NIMAX NIMAX Prehardened LASER LASER WELD None 360–400 HB None

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

Austenitic . 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°CHeat 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 Te m p er hardened ORVAR Hardned (GTAW) UTP A673 325°C (620°F) 57–60 HRC Tempering 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 250–300°CTempering ELMAX** Hardened (GTAW) UTP A 701 (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 Network of excellence

UDDEHOLM is present on every continent. This ensures you high-quality Swedish tool steel and local support wherever you are. ASSAB is our exclusive sales channel, representing Uddeholm in various parts of the world. Together we secure our position as the world’s leading supplier of tooling materials.

www.assab.com www.uddeholm.com UDDEHOLM R-140218

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 develop- ment 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. ASSAB is our exclusive sales channel, representing Uddeholm in various parts of the world. Together we secure our position as the world’s leading supplier of tooling materials. We act worldwide, so there is always an Uddeholm or ASSAB representative close at hand to give local advice and support. For us it is all a matter of trust – in long-term partnerships as well as in developing new products. Trust is something you earn, every day.

For more information, please visit www.uddeholm.com, www.assab.com or your local website.