TIP TIG Welding is always better quality than TIG and 100 to 500% faster with superior quality than TIG - MIG - FCAW.

 

S1 to S7 Tools Steels Reference

(S) Shock Resistant Tool Steels

(S) Steels AISI S1 - S2 - S6 - S7
(S) Steels UNS T4190X
(S) High strength medium wear resitance and ductiloty.
(S) Steels used for tools with high impact requirements.
(S) Steels typicall rockwell range 50 - 60
(S) Steels Harden 1675 F 912 C


Welding:
(S) 5 - 7 Weld Preheat / Interpass max 575F 301 C
After weld cool 150F 65C Then temper 550 - 600F for final hardness
Use low amps, short arc length, small length beads,

Consumables
If hard surface not required use E312 + high strength low hydrogen electrodes.

(S5 - 7) use consumables S7 rod or H12-13

(S) Steels Weldmold SMAW 943-L / Eureka 74

S1 to S7 Tool Steels Properties

 

S1	Germany DIN 1.2550 France 55WC20 carbon 0.55 max Si 1.2 Cr 1.8 W 3.0 Mo 0.5 Rockwell 40 - 58 Anneal 1450F 787C Temper 400F - 1150F
S2	Carbon max 0.55 Mn 0.5 Si 1.2 Mo 0.6 V 0.5 Anneal 1450F 787C Temper 350F - 800F
S5	Carbon max 0.65 Mn 1.0 Si 2.25 Cr 2.0 Mo 1.35 Anneal 1450F 787C Temper 350F - 800F
S6   S7	Carbon max 0.5 Mn 1.5 Si 2.5 Cr 1.5 Mo 0.5 Carbon 0.55 Mn 0.8 Si 1.0 Cr 3.5 Mo 1.8 Anneal 1525F - 829 C Temper 400F - 1150F

Brittleness:The ease at which the weld or metal will break or crack without appreciable deformation. When a metal gets harder it becomes more brittle. Preheat, inter-pass temp controls and post heat all are designed to reduce the potential for brittleness.


GENERAL CONSIDERATIONS FOR WELDING TOOL STEELS:

• Ensure base metals are clean avoid tool marks.
  
  
• Remove all sharp edges and tight corners in weld areas.
  
  
• Use Dye pen to check for surface cracks.
  
  
• Majority of tool steels will be weld repaired in the Hardened condition

A hardness test will determine if steel is hard or annealed.

To weld massive tool parts with large amounts of weld "anneal first"

• Steels in the annealed condition metal can be removed with an oxy acet/fuel torch.
  
  
• Steels in the hardened condition use grinding/carbon arc rather than oxy fuel or plasma to remove metal.
  
  
• Discoloration glazing of steel while grinding indicates damage.
  
  
• Preheating before grinding or oxy cutting prevents damage
  
  
• ALL TOOL STEELS MUST BE PRE HEATED BEFORE WELDING.
  
  
• Pre heat prevents cracking, distortion stresses and shrinking.
  
  
• Annealed or hardened steels the steel must be pre heated.
  
  
• If base metal hardened yet not tempered anneal temper first.
  
  
• Preheat hardened steels don't exceed temper temperature.
  
  
• Hardened steels if temper unknown >25mm use 300 to 400F preheat.
  
  
• Annealed steels, preheat at maximum pre heat recommendation.

If steels are quenched and tempered to match tool steel properties, the
electrode selection and heat treatment recommendations critical.

Hardness:The resistance of the metal or the weld to penetration. Hardness is related to the strength of the metal. A good way to test the effectiveness of the weld procedure after the weld and heat treatment is complete, test the
hardness of weld and the base metal surrounding the weld.

WELDING TOOL STEELS:

With all tool steels the first weld consideration should be does the weld require the same hardness as the base.

Is the metal to be welded in the annealed or hardened condition.

Use lowest possible weld current, (smallest electrode diamaeter)

No weaves use stringer beads.

Peen each weld after completion,

Ensure parts are clean.

Avoid excess joint restraints.

Ductility: The amount that a metal or weld will deform without breaking. Measured on welds by the % of elongation in a 2 inch 51 mm test piece. An E71T-1 flux cored electrode should result in a minimum of 20% elongation. An E70S--6 MIG weld should produce approx 22%.

TOOL STEELS AND SMAW ELECTRODE DATA.

SMAW Electrodes most versatile weld process for tool steels.

Electrode 3/32 2.5mm amperage 50 to 80 amps DCSP

Electrode 1/8 3.2.5mm amperage 70 to 115 amps DCSP

Electrode 5/32 4mm amperage 100 to 150 amps DCSP

Most tool and die SMAW electrodes use AC-DC Positive.

Flux cored good for welds which benefit from high weld depositions.

GTAW, TIG good for small precise welds.

• Don't use oxy fuel to weld.
• Ask. Is the weld for joining or does the weld require a
  specific mechanical property ( hardness or machinability)?
• Use smallest electrodes possible.
• Peen each weld bead.
• Avoid arc strikes.
• Consider run on plates.
• Avoid craters.
• Try to use stringers rather than weaves.
• If possible for the firsts pass (butter pass) consider the E312 electrode except for water hardened steels.
• For water hardened steels use E11018 instead of E312 for butter pass.
• When using E312 use only one layer to avoid shrink cracks.
• If excessive hardness not required in weld use E312 then an E9018-6 or E11018-

   

• FOR LARGE COMPONENTS THAT REQUIRE BOTH STRENGTH AND HARDNESS
• First use E312 followed by E11018-G followed by the tool steel.
• Try to provide a minimum of 3 layers of tool steel weld to a minimum depth of 3mm.
• If the repairs are on annealed steels remember the electrode selected must respond to heat treatment after weld.
• The weld hardness will depend on the preheat/interpass temperatures plus weld procedures.
• The weld hardness will depend on the chemistry of the selected electrode along with the base metal dilution.
• The weld hardness will depend on the post heat treatment and cooling rate time.
• To join components, and prevent cracks preheat and deposit ductile electrodes.
• To prevent cracks, limit carbon pickup in first pass, (use low current narrow stringer beads) also if possible stress relieve.
• To minimize the potential for underbead cracks, preheat and limit heat input during the
  weld.
• To prevent underbead cracks provide uniform cooling, with immediate stress relief.
• Fast heating or concentrated heating can cause cracks.

Toughness: The ability of the metal or weld sample at a predetermined temperature to withstand a shock.The test for toughness measures the impact of a pendulum on a notched specimen. You may see that the required impact properties for the metal or weld are 20ft-lbf @ -20 F (27 j @ -29C) reheat at maximum pre heat recommendation.

TOOL STEELS, PRE HEAT BASICS

M-T-H-D2 Pre heat 900F (482C)

• All other tool steels preheat at 350F (176C)
• Preheat "slowly" The higher the alloy content the slower the preheat.
• Preheat, the more complex the part shape the slower the preheat.
• Preheat. High alloy steels avoid oxy fuel use ovens or electric.
• Preheat. Use insulation around part to retain heat.
• Preheat. Maintain preheat during welds, don't exceed preheat temp.

 

The "yield and tensile strength". The stress that can be applied to a base metal or weld without "permanent deformation" of the metal. The "tensile strength". The ultimate tensile strength, the maximum tensile strength that the metal or weld can with stand before "failure

TOOL STEELS AND PRACTICES TO AVOID CRACKING.

• Annealed steels preheat, for the weld stress relieve, machine harden temper.
• Hardened steels, pre heat, weld temper then grind finish.

   

• DECARBURIZATION = LOSS OF CARBON CAUSES SURFACE SOFTENING.
• Coating surface with Borax prevents decarburization.
  
  
  TEMPERING FOLLOW AFTER QUENCHING TO REDUCE HARDENING STRESSES.
  
  
• High temper provides more toughness with less hardness.
• Tempering at low end provides max hardness (max wear) with less toughness.
• Tempering above Temper range reduces toughness.
• For large repairs on hardened steels use the electrode temper requirements.
• Welding on hardened steels not tempered cracking will occur.
  
  
  
  
  

Brittleness: The ease at which the weld or metal will break or crack without appreciable deformation. When a metal gets harder it becomes more brittle. Preheat, inter-pass temp controls and post heat all are designed to reduce the potential for brittleness.

• STRESS RELIEF - CONTROLLED HEATING & COOLING TO REDUCE STRESS.
• STRESS RELIEF MACHINED PARTS FOR DIMENSIONAL STABILITY.
• STRESS RELIEF SLOW HEATING AND COOLING REQUIRED
• CONFIRM WITH CODE SPECIFICAIONS FOR STRESS RELIEF REQUIREMENTS.

 

Fatigue: The ability of a metal or weld to withstand repeated loads. Fatigue failures occur at stress levels less than the metal or weld yield strength. Some things that can influence fatigue failure:

• Excess weld profiles.
• Welds with undercut.
• FCAW or SMAW slag inclusions.
• Lack of weld penetration.
• Excess weld heat, typically from multi-pass welds without inter-pass temp controls.
• Items to a part that adds restraint while welding.
• Items added to a part that can concentrate stresses in a specific location.
• Incorrect selection of filler metal, weld too weak or weld too strong.

 

STRESS RELIEVING

TYPICAL STRESS RELIEF SOAK TIME ONE HOUR PER INCH OF THICKNESS	SR HEAT & COOL RATE PER HOUR 400oF 204oC DIVIDE THICKER PART
PARTS OF DIFFERENT THICKNESSES SR MAX TEMP DIFFERENCE 75oF 24oC	STRESS RELIEF CARBON STEELS 1100oF 593oC TO 1250oF 677oC
STRESS RELIEF CARBON 0.5% Mo 1100oF 593oC TO 1250oF 677oC	SR 1% CHROME 0.5% Mo 1150oF 621oC TO 1325oF 718oC
SR 1.25 % CHROME 0.5% Mo 1150oF 621oC TO 1325oF 718oC	SR 2% CHROME 0.5% Mo 1150oF 621oC TO 1325oF 718oC
SR 2.25 % CHROME 1% Mo 1200oF 649oC TO 1375oF 746oC	SR 5% CHROME 0.5% Mo 1200oF 649oC TO 1375oF 746oC
SR 7% CHROME 0.5% Mo 1300oF 704oC TO 1400oF 760oC	SR 9% CHROME 1% Mo 1300oF 704oC TO 1400oF 760oC
SR 12% CHROME 410 STEEL 1550oF 843oC TO 1600oF 871oC	SR 16% CHROME 430 STEEL 1400oF 760oC TO 1500oF 815oC
SR 9% NICKEL 1025oF 552oC TO 1085oF 585oC	FOR 300 SERIES STAINLESS SR WILL RESULT IN CARBIDE PRECIPITATION
WITH LOW CARBON 300 SERIES MAX SR 1050oF 566oC	SR 400 SERIES CLAD STAINLESS 1100oF 593oC TO 1350oF 732oC
SR CLAD MONEL INCONEL Cu NICKEL 1150oF 621oC TO 1200oF 649oC	STRESS RELIEF MAGNESIUM AZ31B 0 500oF 260oC 15 MIN
STRESS RELIEF MAGNESIUM AZ31B H24 300oF 149oC 60 MIN	HK31A H24 550oF 288oC 30 MIN HM21A T8-T81 700oF 371oC 30 MIN
MAGNESIUM WITH MORE THAN 1.5% ALUMINUM STRESS RELIEF	MAGNESIUM CAST ALLOYS AM100A 500oF 260oC 60 MIN
AZ-63A 81A 91C & 92A 500oF 260oC 60 MIN

If steels are quenched and tempered to match properties electrode
selection and heat treatment recommendations critical.

Steel 0.15 Carbon Tensile 60- 65 ksi 413 448 MPa Hardness Br 132	HRC 43 Br 400 Tensile 201 ksi 1385 MPa HRC 44 Br 409 Tensile 208 ksi 1434 MPa
Steel 0.3 Carbon Tensile 85 ksi 568 MPa Hardness Br 172	HRC 45 Br 421 Tensile 215 ksi 1482 MPa HRC 46 Br 432 Tensile 222 ksi 1530 MPa
Steel 0.5 Carbon Tensile 100 ksi 689 MPa Hardness Br 219	HRC 47 Br 443 Tensile 229 ksi 1578 MPa HRC 48 Br 455 Tensile 237 ksi 1634 MPa
HRC 20 Br 228 Tensile 111 ksi 765 MPa HRC 21 Br 233 Tensile 113 ksi 779 MPa	HRC 50 Br 481 Tensile 255 ksi 1758 MPa HRC 52 Br 512 Tensile 273 ksi 1882 MPa
HRC 23 Br 243 Tensile 117 ksi 806 MPa HRC 24 Br 247 Tensile 120 ksi 827 MPa	HRC 54 Br 543 Tensile 292 ksi 2013 MPa HRC 56 Br 577 Tensile 313 ksi 2158 MPa
HRC 25 Br 253 Tensile 122 ksi 841 MPa HRC 26 Br 258 Tensile 125 ksi 861 MPa	HRC 58 Br 615
HRC 27 Br 264 Tensile 128 ksi 882 MPa HRC 28 Br 271 Tensile 132 ksi 910 MPa
HRC 29 Br 279 Tensile 132 ksi 910 MPa HRC 30 Br 286 Tensile 138 ksi 951 MPa
HRC 31 Br 294 Tensile 142 ksi 979 MPa HRC 32 Br 301 Tensile 145 ksi 999 MPa
HRC 33 Br 311 Tensile 149 ksi 1027 MPa HRC 34 Br 319 Tensile 153 ksi 1054 MPa
HRC 35 Br 327 Tensile 157 ksi 1082 MPa HRC 36 Br 336 Tensile 162 ksi 1116 MPa
HRC 37 Br 344 Tensile 167 ksi 1151 MPa HRC 38 Br 353 Tensile 171 ksi 1179 MPa
HRC 39 Br 362 Tensile 176 ksi 1213 MPa HRC 40 Br 371 Tensile 181 ksi 1247 MPa
HRC 41 Br 381 Tensile 188 ksi 1296 MPa HRC 42 Br 390 Tensile 194 ksi 1337 MPa

• DECARBURIZATION = LOSS OF CARBON CAUSES SURFACE SOFTENING.
• Coating surface with Borax prevents decarburization.
  
  
• ANNEAL HEAT ABOVE CRITICAL TEMP THEN COOL 50F (10C) PER HR TO TEMPER.
  
  
• STRESS RELIEVE BELOW CRITICAL TEMP. TYPICAL 1100-1300F (700C) WITH SLOW COOL. Don't stress relieve a weld on hardened steel.
  
  
• TEMPERING FOLLOW AFTER QUENCHING TO REDUCE HARDENING STRESSES.
• High temper provides more toughness with less hardness.
• Tempering at low end provides max hardness (max wear) with less toughness.
• Tempering above Temper range reduces toughness.
• With hardened steel let steel cool to 150F (65c) then temper.
• For large repairs on hardened steels use the electrode temper requirements.
• Welding on hardened steels not tempered cracking will occur.

Tool Steels Reference (A) Air Hardened.

Tool Steels Reference(D) High Carbon Chrome Cold Worked.

Tool Steels Reference (H) Chrome, Tungsten and Moly.

Tool Steels Reference (L) Low Alloy High Wear Resistance / Toughness.

Tool Steels Reference (M) Moly High Speed Steels.

Tool Steels Reference (O) Oil Hardened Cold Worked.

Tool Steels Reference (P) Low Carbon Mold Steels.

Tool Steels Reference (S) High Strength Medium Wear Resistance & Ductility.

Tool Steels Reference (T) Tungsten High Speed Steels.

Tool Steels Reference (W) Water Hardened Tool Steels.

• Tool Steels Reference (A) Air Hardened.
• Tool Steels Reference(D) High Carbon Chrome Cold Worked.
• Tool Steels Reference (H) Chrome, Tungsten and Moly.
• Tool Steels Reference (L) Low Alloy High Wear Resistance / Toughness.
• Tool Steels Reference (M) Moly High Speed Steels
• Tool Steels Reference (O) Oil Hardened Cold Worked.
• Tool Steels Reference (P) Low Carbon Mold Steels.
• Tool Steels Reference (S) High Strength Medium Wear Resistance & Ductility.
• Tool Steels Reference (T) Tungsten High Speed Steels.
• Tool Steels Reference (W) Water Hardened Tool Steels.