Download - Welding engineering - Subject brief - CE
TRADE SCHOOL BRIEFS, (091413)
WELDING HINTSSTEEL WITH A HIGH CARBON CONTENT
RALPH BATEMAN
WELDING
• WITHIN THE CRAFT OF WELDING, THE FINISHED PRODUCT IS OF SECONDARY CONSEQUENCE.
• THE MOST IMPORTANT FACTOR IS NOT WHAT WE WELD… IT’S WHAT WE WELD.
• CONFUSED?
I’M REFERRING OF COURSE TO THE MATERIAL, AND NOT ANY PARTICULAR
FINISHED GOODS…
WELDERS WELD METAL.
NOT CARS OR PRESSURE VESSELS OR PIPES OR
STRUCTURE… WE WELD METAL.
Introduction
WELDING
• WE USE TOOLS AND PROCEDURES SPECIFICALLY DESIGNED THAT ALLOW US TO PLY OUR TRADE..
• WE ARE ARTISTS… CRAFTERS OF MOLTEN METAL.
• WE PRODUCE PRODUCTS THAT DRIVE MODERN CIVILIZATION THROUGH THE TWENTY FIRST CENTURY.
WELDERS WELD METAL.
Introduction
WELDING
• WE’RE YOU’RE BLACKSMITH’S, YOU’RE RIVETERS, YOU’RE WELDERS.
• WE CONTROL LIGHTENING AT OUR FINGERTIPS.
• WE WORK THE HEAVY STEEL.
• WE WORK THE HIGH STEEL..
• WE WORK THE HEAVY STEEL UP ON HIGH…
WELDERS WELD METAL.
Introduction
WELDING
• WE ARE PROUD, GOOD LOOKING AND BRAVE. WE ARE THE BEST LOV..
OPPS!.. WRONG PRESENTATION..
IF I HAVEN'T MENTIONED IT,
WE WELD METAL
WELDERS WELD METAL.
..AND OUR SKILLS AND ABILITIES ALLOW US TO JOIN
ANY METAL PRODUCT
Introduction
HINT
KNOW THE MATERIAL
BUT REMEMBER…NOT ALL STEELS ARE EQUAL!
IT’S ABOUT THE MATERIAL
>
All
ALWAYS CHECK THE
MILL CERTIFICATE.
IF YOUR SUPERVISOR DOES NOT GIVE OR SHOW YOU COPY.. ASK
FOR IT!
KNOW THE MATERIAL
KNOW THE MATERIAL
YOU NEED TO SEE IT TO DETERMINE
THE
WELDABILITY
OF THE METAL YOU’RE ABOUT TO
WELD.
STEEL IS AN ALLOY
THIS MEANS THAT JUST LIKE YOUR MOM’S APPLE PIE, DIFFERENT INGREDIENTS WERE USED TO
PRODUCE IT.
IT’S THESE ‘INGREDIENTS’ THAT AFFECT
‘WELDABILITY’
… AND YOUR ABILITY TO WELD IT.
STEEL IS AN ALLOY
APPRECIATING THE AFFECTS OF THE INGREDIENTS FOUND IN STEEL WILL MAKE YOU MORE KNOWLEDGEABLE IN YOUR
CRAFT.
It will also make you a better welder..
KNOW THE MATERIAL
LOW COST, IMPORTED STEELS & REDUCED LEVELS OF DOMESTIC VIRGIN STEEL CAN PROVIDE A
CHALLENGE WHEN JOINING THESE METALS.
ALL STEEL IS AN ALLOY
SOME ALLOYS AND PARTICULARLY THOSE ALLOYS
REFERRED TO AS ‘EXOTIC’ DEMAND CARE AND
CONSIDERATION BEFORE STRIKING THE WELDING ARC.
…Never assume a metal is ‘easy’ to weld, check out that Mill cert. before striking an arc
CARBON IS THE MOST SIGNIFICANT ALLOYING ELEMENT THAT AFFECTS
WELDABILITY. THE SUM TOTAL OF OTHER
ELEMENTS FOUND IN STEEL CAN HAVE A SIMILAR EFFECT AS PURE
HIGH CARBON.
WE CALL THIS THE
CARBON EQUIVALENT
OR
CE VALUE
ALL STEEL IS AN ALLOY
ALWAYS BE AWARE OF THE CE VALUE BEFORE WELDING
HEAVY SECTION STEEL WELDMENTS.
FORMULA TO CALCULATE THE CARBON EQUIVALENT
OF STEEL >>>
THE HIGHER THE VALUE IN EXCESS OF 0.3, THE GREATER THE NEGATIVE IMPACT ON THE STEELS
WELDABILITY
(IT WILL BE INCREASINGLY MORE DIFFICULT TO WELD AND MAY REQUIRE CONTROLLED HEAT TREATMENT)
CE = C +Mn
+Cr + Mo + V
+Ni + Cu
6 5 15
The values for the chemical elements contained inThe steel you’re about to weld will be found in the
mill certificate supplied with the steel.
Plug those values into the formula below todetermine the CE (Carbon Equivalent) of the steel.
(Always include your Engineering resource in these situations)
ALL STEEL IS AN ALLOY
CAUTION.. CE ALERT
BE AWARE OF AND FOLLOW YOUR WPS, CAREFULLY WORKING WITHIN THE ALLOWABLE PARAMETERS AT ALL TIMES. BE EXTRA CAUTIOUS IF HEAT TREATMENT IS CALLED OUT
AND YOU’LL MINIMIZE THE RISK OF MULTIPLE DEFECTS THAT MAY NOT BECOME EVIDENT UNTIL AFTER THE PRODUCT IS IN SERVICE..
WELDING DEFECTS OCCUR PRIMARILY DUE TO IMPROPER
PROCESS, WELDING TECHNIQUE AND WELD CONTAMINATION.
ALWAYS BE AWARE OF THE MATERIAL YOU’RE WELDING.
FOR INFORMATION ON CORROSIVE DEFECTS SUCH AS
HYDROGEN INDUCED CRACKING…
AND FOR ALL YOUR TRAINING NEEDS, CONTACT LABORIGHT
TODAY
WWW.LABORIGHT.COM
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