what is types of welding defects ?
457811
The types of defects and their definition can vary with the code being applied. You need to know which code to understand the items defined as a defect.
517351
The pure type of metal and the alloy
793957
This is the part of the flame where ample oxygen is available for complete oxidation of vapors.  This blue flame occurs most often when supplemental oxygen is forced into the flame.  An example of this is best observed with welding torches --  such as acetylene torches.  With oxygen cut off, the flame is all yellow.  But as oxygen is added, the flame becomes blue -- and much hotter as well!
311283
http://www.corrosion-doctors.org/Forms/embrittlement.htm
333517
cinder cones\ncomposite cones\nshield
555540
Not sure about using "welding rod", but I know you can spot weld and ultrasonically weld Polystyrene to Polystyrene quite well.  There is "General Purpose" and "Rubber Modified" Polystyrene.  The rubber modified is easier for spot welding, swaging and staking, so I'd assume is easier for other methods of welding.  If you use welding rod, it would need to be Polystyrene (You may get some bonding with Polycarbonate as well).  Haven't seen welding rod in either of these materials though....  maybe someone else has??
513263
Spiral, lenticular, elliptical and irregular\n\nSee the link
557678
Ah ha.  Thermite.  Magnesium ribbon would be the usual method to start this reaction.\n\nBe careful with this reaction...
707065
A butt weld is the most common for pipe to pipe connections. Depending on the size, pipe fittings normally are butt welds or socket welds. Smaller connections (2" and smaller more or less) can be socket weld (fillet) or butt welds. Larger than 2" (more or less) are typically butt weld. \n\nFor flanges, in addition to butt weld and socketweld, slip on flanges are also available. They usually require two fillet welds one on the inside and the other on the outside.
92636
The three types of ferrous metals are cast irons, steels, and iron.\n\nThe link will give applications of each.
944951
Flame tests show the color of the metal (the positive ion). The negative ion is usually nitrate (NO3) or sulfate (SO4) which are colorless.
243204
eye problems\nhand/wrist problems\ndietary deficiency\nphysical exercise deficiency\nsocial/communication problems
988480
Qualification of welders by completion of the welds on a test sample that can then be checked for quality of the weld
775528
There are a lot of Inconel alloys, but I think they are primarily nickel based, not iron.  They are used for high temperature applications such as jet engines.  \n\nWhile they can be welded, you really need to be careful if there are any safety concerns, that the welding doesn't introduce any problems.
1129829
Incomplete combustion of any material.
315935
1- Thermal Cracks.\n2- Some Stresses before complete hardening.\n3- No Good Curing.\n4- Expantion or Shrinkage.
421137
MSDS of rustripper\n\nhttp://msds.ogden.disa.mil/msds/owa/web_msds.display?imsdsnr=198627