Product Information
The chemistry of our 30 electrode comprises the one formulation that is unique in being fully compatible with the chemistry of every standard grade of steel manufactured today.
Previously, most maintenance departments had to stock many different types of steel welding electrodes to accomplish the variety of applications that occur from time to time in maintenance. Now many maintenance departments have found it prudent to stock only our 30 rod for all their steel welding. This reduces inventory enormously as well as preventing misapplications.
Increased Safety:Many costly and dangerous weld failures occur because of improper identification of the steel to be welded. In maintenance, especially when welding on old equipment, the analysis is not known. A welder may incorrectly identify the steel as low carbon or mild steel and weld it with a mild steel electrode. If a steel having 90,000 psi tensile strength is welded with an electrode having only 60,000 psi tensile strength, the weld is certain to fail in service causing costly downtime and possibly a dangerous accident.
If a welder assumes that a structure of high carbon steel is a low alloy steel and welds it with a low hydrogen electrode, the hydrogen electrode has such intense penetration that there is likely to be such a large amount of carbon pick-up and dilution in the weld metal that the weld will be brittle and rupture in service.
Remarkably high tensile strength, yield strength, & high holding power: Our 30 electrode has such incredible holding power that a fillet weld of four passes of a 30 is generally equivalent in strength to a fillet weld of 16 passes of a mild steel electrode.
A fillet weld of the size {figure 1} made with 30 has equal or greater holding power than fillet weld made with mild steel electrodes, the size of figure 2.
A fillet weld made with 30 {figure 1} theoretically has the same holding power as the fillet weld in figure 2 made with a mild steel electrode.
By reducing the throat size 50%, with 30 the amount of weld metal required is only 1/4th as much. This means a 75% savings in electrodes and welder's time, electric power, and costly downtime.
When one considers that our 30 electrode can provide that holding power of 4 mild steel electrodes the economy, as well as the reliability and versatility of 30 is obvious.
Since 30 has double the tensile strength of a steel electrode, the throat size of the 30 fillet weld need only be 1/2 as large as the throat size of a weld made with mild steel electrodes. The economy is not only in the fact that less electrodes are used, but more importantly, the job is completed in a fraction of the time, reducing labor costs and costly downtime on broken down machinery.
Even more important may be the fact that stress, distortion, warpage, grain growth and the other harmful effects that making larger size fillets cause are eliminated. In most cases, 30 is the most economical electrode available.
30 increases its tensile strength in use due to its fine work hardening qualities--the longer you use it the stronger it gets. Its ultimate tensile strength is approximately 120,000 psi.
30 is not crack sensitive like AISI 310 type stainless steel electrodes are, and in addition has 50% more tensile strength. (An AISI type stainless steel electrode is commonly referred to as "25-20" because it has approximately 25% chromium and 20% nickel content.)
The super high holding power of 30 is especially important in maintenance applications, even on mild steel. Often a maintenance repair must be made in areas of poor accessibility, or there is another part in the way obstructing the possibility of a continuous weld, or a weld that is adequate in length or size of location to hold a part. Because of 30's super high holding power a partial weld, a weld much smaller than usual, or a weld on only one side of the member will provide reliability whereas the repair would have been impossible with ordinary steel electrodes.
The fact that a much smaller amount of 30 can be used to form a fillet weld means there is less distortion, less warpage and less stress. Stress and distortion are related to the dimensional size of a weld--the larger the weld, the more stress and distortion.
Perhaps the outstanding quality of this electrode is its ability to resist cracking. The original 30 electrode was developed nearly 40 years ago. It was said by many engineers and metallurgists who tested it upon its introduction that it was consistently the most crack resistant electrode they had ever tested. During the years it has been continuously improved. Because 30 is one of the most widely used electrodes in the world, a continuous testing and research program on 30 is constantly being conducted to endeavor to improve it further.
The remarkable resistance of 30 to virtually all types or causes of cracking is related to several outstanding features:
FIRST
30 contains a judicious use of aluminum oxide in carefully controlled percentages, along with exact percentages of ferrite formers that achieve several most remarkable results. They create an incredibly fine-grained microstructure in the weld that suppresses the possibility of cracks.
SECOND
The unique composition and balance of ferrite to austenite causes the tendency of a layer of soft delta ferrite to encapsulate each austenitic grain and these ferrite layers act as a built-in shock absorber. One special quality of 30 is the unique grain structure which enables it to stretch without cracking.
THIRD
30's structure is such that it neutralizes the otherwise harmful effects of carbon pick-up or dilution in the weld metal, thus retarding and eliminating both center bead cracking and side bead cracking in high and medium carbon steels.
FOURTH
30's highly controlled penetration rate has been engineered into the electrode by creating an exceedingly highly ionized arc column of moderate force which is highly directional. This penetration is so controlled that it is in the order of 30-35%. This is an ideally engineered penetration which provides optimum strength, yet enables the electrode to perform with excellent results on difficult to weld steels, dissimilar steels, and high alloy steels without harmful dilution and harmful carbon or contamination pick-up.
FIFTH
30 has a controlled silicon content. Most so-called high tensile strength electrodes have less than 0.50% silicon and in general the amount varies greatly from batch to batch. There are few electrodes indeed that consistently have more than 0.50% silicon. It has repeatedly been proven that a higher silicon content reinforces the grain structure and prevents cracking. Our research has managed to control deposit silicon between 1.5% and 1.8% to revolutionize the crack resistance of the electrode. Silicon is not only a ferrite former, but in addition it improves the distribution of ferrite throughout the weld deposit.
Many electrodes do not exhibit cracking when a short arc is held by the welder, and thus, laboratory tests indicate the electrode is not crack sensitive. In maintenance, however, laboratory conditions do not prevail and the welder often works in areas that are difficult to reach or our of position where a long arc has to be used. In these circumstances, where a long arc is employed, many lose some of their ingredients into the atmosphere in the transfer across the arc when a long arc is held.
30, being designed for all maintenance conditions, shows a decided resistance to cracking even if a long arc is held. 30 is a super high tensile strength electrode which is virtually insensitive to arc length, and thus fully meets the requirements of maintenance conditions.
*Weld deposits of 30 can be water quenched (or rapidly weather quenched when welding in cold climates) with no ill effects on its physical properties.
*30 has high resistance properties. It will resist impact equal to or superior to manganese steel, nickel manganese steel, and moly-manganese steel or other steels especially designed for impact resistance.
Requires No Embrittling Heat Treatment to Obtain High Tensile Strength:There are various welding electrodes, such as the high carbon high chrome steel which will equal the remarkable tensile strength of 30 under certain conditions. However, most of these have to be heat-treated to obtain this high tensile strength, resulting in low elongation and brittleness. 30 deposits have a super high tensile strength without heat treatment, thus retaining high elongation and ductility while still providing extraordinary holding power.
Excellent Weldability:30 contains high silica fortified with potent arc stabilizing titanates, providing ultra high ionization which greatly increases the weldability on alternating current. 30 provides an unusually fine droplet type of transfer which is unusual for such a highly alloyed electrode. The arc gap is actually insensitive and can be varied from contact to medium long without loss of arc stability. Even amateur welders can apply 30 without "arc sticking".
The electrode deposit has a virtually self-releasing slag, which completely eliminates any possibility of slag entrapment which is so often the cause of failure in multi-pass weldments.
From an engineering point of view, there is no possibility of undercut because of the unique combination of controlled arc-drive and fluidity. The fluidity is caused by a breaking down of surface tension which enables the electrode to "wash outward" rather "drip." As is well known, undercutting causes notches that often lead to weld failure. The automatic avoidance of undercutting by 30 marks a step forward in maintenance welding. Highly skilled welders avoid undercutting by special "whipping" techniques but with 30 the automatic "wash" enables even unskilled welders to weld repair top notch sensitive steel. 30 has easy strike and restrike qualities, the electrode does not overheat and the entire electrode (except a short stub) can be used.
