|
This Page Presents Welding 4130 Chrome Moly Math,
and Other Information About Welding 4130:
Click for BASIC 4130 WELDING
DETAILS
Click for
TECHNICAL & METALLURGICAL DETAILS
Click for
WELDING HEAT TREATED 4130 CHROME MOLY
Click for
METALLURGICAL DEFINITIONS
Click for WELDING A BETTER
STEEL; HY 130 |
|
MIG Gas Delivery and the Small Block Chevy
Evolved in a Similar Way and Time!
Both had Advances and
Setbacks Before
They Were Optimized!
Click
for a PDF Report on the Similarities |
|
Math Used to Generate 4130
Information. |
The Information Below;
 | Provides the math equations that estimate
the theoretical
cooling rates for TIG welds in thin wall 4130 tubes. |
| The cooling rate equations were obtained from the Welding Handbook,
Volume 1, 9th Edition, page 100. |
| Both thick and thin plate equations were developed by Professor C.A.
Adams et al.
|
|
| The data is presented in a way so one can see the numbers
from each part of the equation. As the thickness was increased so was the
heat input. A TIG process efficiency of 0.5 (50%) was used which is
higher than the sited Welding Handbook reference but errors on the side of
predicting a slower cooling rate. The thin plate equation is for two
dimensional heat flow and may be OK for a butt weld but a Tee fillet weld
will have faster cooling rate. Therefore despite trying to error on the side
of predicting slower cooling rates, they are all around the 1/4 in Jominy
bar location. The exact cooling rate will be somewhat dependent on the diameter of
the tube as well. However I would expect that perhaps 1/2 way around the
joint the cooling rate would be similar to that predicted. As the complete
circular weld is made the last part will have a preheat from the weld start.
However if a brittle structure is formed in any area and a crack forms, that
is sufficient to be a problem.
|
Equation Elements and Values
|
Rc = Cooling rate
at weld centerline; deg F/min |
|
k = Thermal Conductivity of
metal; BTU/min in deg F |
|
p = Density of metal; lb/in3 |
|
C = Specific Heat of metal;
BTU/ (lb deg F) |
|
h = thickness of metal; in |
|
Hnet = Net heat
input; BTU/in [V*I / ipm*.057*process efficiency] |
|
Tc = Temperature
which cooling rate is calculated; deg F |
|
To = Initial
plate temperature; deg F |
Welding Cooling Equations from
pp 100 Welding Handbook Volume 1, 9th Edition |
| Thick Plate Equation =Rc =-[2*3.1416*k(Tc-To)2]
/ Hnet |
| Thin Plate Equation = Rc =
2*3.1416*kpC (h/Hnet)2(Tc-To)3 |
|
Calculate estimated cooling
rate @ 1100 deg F for thin wall 4130 tube welds:
Tube = .040 in wall; V (volts)
= 10; I (amps) = 70; travel = 12 ipm
Using thin plate equation:
| -2*3.1416*0.024*0.29*0.11= -.00481 |
| Hnet = 1.66 |
| (h/Hnet)2 = 0.000579 |
| (Tc-To)3 = 1.07*109 |
| Rc = -2981 deg F / min = - 50 deg F / sec |
|
| Tube = .0625 in wall; V (volts) = 10; I
(amps) = 90; travel = 11 ipm
Using thin plate equation:
| -2*3.1416*0.024*0.29*0.11= -.00481 |
| Hnet = 2.33 |
| (h/Hnet)2 = 0.000718 |
| (Tc-To)3 = 1.07*109 |
| Rc = -3700 deg F / min = - 62 deg F / sec |
|
| Tube = .093 in wall; V (volts) = 10; I
(amps) = 110; travel = 9 ipm
Using thin plate equation:
| -2*3.1416*0.024*0.29*0.11= -.00481 |
| Hnet = 3.48 |
| (h/Hnet)2 = 0.000713 |
| (Tc-To)3 = 1.07*109 |
| Rc = -3671 deg F / min = - 61 deg F / sec |
|
REFERENCES USED;
| US Steel Atlas of Isothermal Transformation Diagrams |
| Republic Alloy steels |
| R. A. Grange and Kiefer; "Transformation of Austenite on Continuous
Cooling and Relation to Transformation at Constant Temperature." |
| Walter Crafts and John Lamont; "Hardenability and Steel Selection." |
| AWS Welding Handbook; Volume 1, 9th Addition |
|
| If a Search Engine Found This Page 1st- - - We'd Suggest
a Visit to The Basic Welding 4130 Page; Then Return. Click
Here This page presents the equations that support
the data in the 4130 Technical Details page.
|
|
This Ad Helps Bring You
Free Information on Welding Race Cars & Street Rods
Have a Welder? Improve Weld Starts and
Have Shielding Gas Cylinder Last at Least Twice as Long!
Note: Our Patented
GSS
is Not Available in "Stores"
A home shop fabricator
in Georgia with a Miller TM 175 amp welder
purchased a 50 foot Gas Saver System ( GSSTM
) so he could use a larger cylinder
and mount it on the wall of his shop. He wrote:
"The system works great.
Thanks for the professional service and
a great product."
Click To See His Home Shop
A Professional
Street Rod Builder Had This to Say:
With their standard MIG welder gas delivery hose the
peak shielding flow at weld start was measured at 150 CFH. That caused air
to be sucked into the gas stream causing poor weld starts. With the
GSS replacing their existing
hose, the peak flow surge at the weld start was about 50 CFH. Total gas use
was cut in half.
Kyle Bond, President, quickly saw the improvement
achieved in weld start quality as a significant advantage! Kyle, an
excellent automotive painter, was well aware of the effects of gas surge
caused by pressure buildup in the delivery hose when stopped. He has to
deal with the visible effects in the air hose lines on the spray gun in his
paint booth! The paint surge is visible and creates defects unless the gun
is triggered off the part being painted! We can’t do that with our MIG gun!
|
|
Thanks to those "Car Crazy" folks who have purchased
the Gas Saver System and commented on the improved starts and reduced gas usage
they have achieved. Many purchased our 6 foot prefitted
GSS,
Part Number WAT FB6,
a 3 foot system, FB3, is also available.
ONE PAGE SUMMARY
 PURCHASE
PRODUCT
FREE Corvette Accessory Installation Info
.
Check Out Welding
Math Site
|
|
This Page Presents Welding 4130 Math, for
Other Information:
Click for BASIC 4130 WELDING
DETAILS
Click for
TECHNICAL & METALLURGICAL DETAILS
Click for
EQUATIONS
defining weld cooling rate in tubing
Click for
WELDING HEAT TREATED 4130 CHROME MOLY
Click for
METALLURGICAL DEFINITIONS
Click for WELDING A BETTER
STEEL; HY 130 |
"WARNING: "Weld
Safely"
|
