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ED CRAIG. www.weldreality.com.

The world's largest website on MIG - Flux Cored - TIG Welding


(A) Tool Steels Weld Data. Air Hardening Medium Alloy.

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

 
 
   





Written by Ed Craig www.weldreality.com



As changes are frequent, please refresh before reading.





Tool Steels Reference A2 to A10

(A) TOOL STEELS. AIR HARDENING MEDIUM ALLOY, COLD WORKED.



(A) Steels. AISI / SAE A2/A3/A4/A6/A7/A8/A9/A10. UNS T301XX - ASTM A681

(A) Steels. Used for forming punches roll shears, knifes and die gages.

(A) Steels. Carbon 0.045 to 2.85% / Manganese to 2.1% / Chrome to 5.7%

(A) Steels. About 60% machinability of (W) steels. W steels = 100%

(A) Steels. Readily Hardened with minimum distortion.

(A) Steels. Not as prone to cracking as (D) steels.

(A) Steels. Generally less wear resistance than (D) steels. A7 steel is exception as it has wear resistance equal to (D) steels.

(A) Steels good toughness with resistance to wear and cracking.

(A) Steels. Typical Hardness range 50 to 67 HRC (A9 35-56 HRC)



Tool Steels A2 to A10

A2UNS T30102 /
France - Z 100 CDV 5
Germany - Din 1.2363
Japan - SKD 12
UK - BA2
Sweden 2260
Carbon 1.5 max/Mn 1.0 max/ Si 0.5 max/Cr 5.5 max/Ni 0.3 max/Mo 1.4 max./ V 0.5 max.

Annealing Temp 1600F
Hardening Temp 1775F
Tempering Temp 350-1000F
Weld Preheat 300 - 500F
Interpass Max 300Ff
Large repairs increase preheat to 750F. After weld cool to 400F Temper/preheat one hr/inch
A3UNS T30103
Annealing Temp 1600F
Hardening Temp 1775F
Tempering Temp 350-1000F
After weld cool to 400F Tem
per/Preheat one hr/inch
A4UNS T30104
Annealing Temp 1400F
Hardening Temp 1500F
Tempering Temp 350-800F
Weld Preheat 300 - 500F
Interpass Max 300F

After weld cool to 400F T
emper/preheat one hr/inch
A6 UNS T 30106
Hardening Temp 1500F
Tempering Temp 350-800F
After weld cool to 400F Temper/preheat one hr/inch

A7 UNS T30107
Annealing Temp 1600F
Hardening Temp 1775F
Tempering Temp 350-1000F
After weld cool to 400F Temper/preheat one hr/inch
A8 UNS T 30108
Annealing Temp 1600F
Hardening Temp 1850F
Tempering Temp 350-1000F
After weld cool to 400F Temper/preheat one hr/inch
A9 UNS T30109
Annealing Temp 1600F
Hardening Temp 1850F
Tempering Temp 950-1150F
After weld cool to 400F Temper/preheat one hr/inch
A10 UNS T30110
Annealing Temp 1400F
Hardening Temp 1500F
Tempering Temp 350-800F
After weld cool to 400F Temper/preheat one hr/inch

 


 

What is 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 the tool 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.

What is 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.


What is 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 try a E312 electrode 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.


What is 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.

 

What is 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.




STRESS RELIEVING (SR) BASIC GUIDELINES:

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.

 

 

What is Fatigue?:
Fatique is 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.

Welds made with 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
    400F 204C DIVIDE THICKER PART
    PARTS OF DIFFERENT THICKNESSES
    SR MAX TEMP DIFFERENCE 75F 24C
    STRESS RELIEF CARBON STEELS
    1100F 593C TO 1250F 677C
    STRESS RELIEF CARBON 0.5% Mo
    1100oF 593C TO 1250F 677C
    SR 1% CHROME 0.5% Mo
    1150oF 621C TO 1325F 718C
    SR 1.25 % CHROME 0.5% Mo
    1150F 621C TO 1325F 718C
    SR 2% CHROME 0.5% Mo
    1150F 621C TO 1325F 718C
    SR 2.25 % CHROME 1% Mo
    1200F 649C TO 1375F 746C
    SR 5% CHROME 0.5% Mo
    1200oF 649oC TO 1375F 746C
    SR 7% CHROME 0.5% Mo
    1300F 704C TO 1400F 760C
    SR 9% CHROME 1% Mo
    1300F 704C TO 1400F 760C
    SR 12% CHROME 410 STEEL
    1550F 843C TO 1600F 871C
    SR 16% CHROME 430 STEEL
    1400oF 760C TO 1500F 815C
    SR 9% NICKEL
    1025F 552C TO 1085F 585C
    FOR 300 SERIES STAINLESS SR WILL
    RESULT IN CARBIDE PRECIPITATION
    WITH LOW CARBON 300 SERIES
    MAX SR 1050F 566C
    SR 400 SERIES CLAD STAINLESS
    1100F 593C TO 1350F 732C
    SR CLAD MONEL INCONEL Cu NICKEL
    1150F 621C TO 1200F 649C
    STRESS RELIEF MAGNESIUM AZ31B 0
    500F 260C 15 MIN
    STRESS RELIEF MAGNESIUM AZ31B
    H24 300oF 149C 60 MIN

    HK31A H24 550F 288C 30 MIN

    HM21A T8-T81 700F 371C 30 MIN

    MAGNESIUM WITH MORE THAN 1.5%
    ALUMINUM STRESS RELIEF
    MAGNESIUM CAST ALLOYS AM100A
    500F 260C 60 MIN
    AZ-63A 81A 91C & 92A
    500F 260C 60 MIN
     




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



    HARDNESS CONVERSION FOR CARBON AND LOW ALLOY STEELS.
    1000 psi = ksi x 6.894 = MPa

    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 require high quality welds with the lowest weld heat, take a look at

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