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Join Date: Sep 2010
Posts: 2

Regarding Welding

09/13/2010 12:14 AM

why gas purging given to ss?why not for cs?

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Guru
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#1

Re: regarding welding

09/13/2010 12:28 AM

In case you point to the shielding gas, used with MIG or TIG welding, for both materials, if you refer to Carbon Steel as CS, and SS as stainless steel you will need to use gas to protect the weld against oxygen influence. Depending on the composition of the steel, different gases are applicable. From Argon, CO2, to different mixtures with other gas. Refer to your welding material supplier which to use in combination with your welding process.

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#2

Re: regarding welding

09/13/2010 3:17 AM

Good evening,

Great Question...

SS, Stainless steel has chromium in it which will emit free electrons to augment self cleaning action acting as a cathode resisting oxidation whilst welding or at ambient temp. You should always hook your ground clamp on weldment, then stinger as positive polarity, this offers optimal self cleaning action of electron flow from metal to electrode stinger.

CS, Carbon Steel is made up having carbon chains within the metallurgy to provide flexibility or hardness if quenched which can too easily combine and oxidize once heated; CO2 / Argon mix or flux is necessary for a shielding gas to prevent such oxidation. Check out my welding device Thunder-Weld I developed, patented and am improving, for sale online to Government Contractors / Agencies... Hope this helps...

Best,

C. Tyson Fisk

Owner,

www.ArcJetWeld.US

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Guru
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#3
In reply to #2

Re: regarding welding

09/13/2010 8:06 AM

Most of all the CS group have a mixture of components. And talking about gas or no gas, this is process related. Stainless steel can also be weld with DC and/or AC electrodes and NO GAS. Also please look of the components in CS steel. Some types are that close, that they miss being stainless by a hair.

I also have seen a lot of welding straight with heavy batteries. I couldn't find no real technical specs on the referred website. Maybe you have more, now, that your system is patented? It will certainly give some meaning and be appreciated by this engineering forum.

Regards and have a look:

Carbon Steel Composition The chemical compositions of the materials are also established by the material specifications for each type or grade of material. The elements that are not identified should not be present in more than trace amounts—except iron, of course, the primary constituent of carbon steels.

Single values are minimums unless otherwise identified, and ranges are given for other elements. The UNS number is listed again for convenience and because the main criteria used to establish that identification is the chemical composition.

The heat analysis is given unless otherwise noted. Although this is the analysis taken from the molten heat and given on the certified material test report, the actual composition of the end product might vary in excess of the heat analysis due to fluctuations that occur during solidification and processing. The limits on the product analysis are therefore somewhat less restrictive than those of the heat analysis.

As previously discussed, the alloying that is used for the materials covered by this report is limited primarily to carbon, manganese, and silicon added in limited and varying percentages to the iron base. In spite of this limited alloying, the properties of the materials are wide-ranging.. The metallurgical structure and the carbon content are major contributors to the overall properties of the different carbon steel materials. Materials classified as carbon steel might also contain small amounts of other elements, such as chromium, nickel, molybdenum, copper, vanadium, niobium (columbium), phosphorous, and sulfur.

Each element that is added to the basic constituent of iron has some effect on the end properties of the material and how that material reacts to fabrication processes. The alloying additions are responsible for many of Metallurgy the differences between the various types or grades of carbon steels.

Following is a list of the elements commonly added to iron and their effects on the material:
Carbon. Carbon is the most important alloying element in steel and can be present up to 2% (although most welded steels have less than 0.5%). The carbon can exist either dissolved in the iron or in a combined form, such as iron carbide (Fe3C). Increased amounts of carbon increase hardness and tensile strength as well as response to heat treatment (hardenability). On the other hand, increased amounts of carbon reduce weldability.

Manganese. Steels usually contain at least 0.3% manganese, which acts in a three-fold manner: it assists in deoxidation of the steel, prevents the formation of iron sulfide inclusions, and promotes greater strength by increasing the hardenability of the steel. Amounts up to 1.5% are commonly found in carbon steels.

Silicon. Usually, only small amounts (0.2%, for example) are present in rolled steel when silicon is used as a deoxidizer. However, in steel castings, 0.35–1.0% is common. Silicon dissolves in iron and tends to strengthen it. Weld metal usually contains approximately 0.5% silicon as a deoxidizer. Some filler metals can contain up to 1.0% to provide enhanced cleaning and deoxidation for welding on contaminated surfaces. When these filler metals are used for welding of clean surfaces, the resulting weld metal strength will be markedly increased. The resulting decrease in ductility could present cracking problems in some situations.

Sulfur. This is an undesirable impurity in steel rather than an alloying element. Special effort is made to eliminate or minimize sulfur during steelmaking. In amounts exceeding 0.05%, it tends to cause brittleness and reduce weldability. Additions of sulfur in amounts from 0.1% to 0.3% will tend to improve the machinability of steel but impair weldability. These types of steel can be referred to as freemachining.

Phosphorus. Phosphorus is also considered to be an undesirable impurity in steels. It is normally found in amounts up to 0.04% in most carbon steels. In hardened steels, it tends to cause embrittlement. In low-alloy, high-strength steels, phosphorus can be added in amounts up to 0.10% to improve both strength and corrosion resistance, although it is not generally added for this reason in carbon steels.

Chromium. Chromium is a powerful alloying element in steel. It is added for two principal reasons: first, it greatly increases the hardenability of steel; second, it markedly improves the corrosion resistance of iron and steel in oxidizing types of media. Its presence in some steels could cause excessive hardness and cracking in and adjacent to the weld. Stainless steels contain chromium in amounts exceeding 12%.

Molybdenum. This element is a strong carbide former and is usually present in alloy steels in amounts less than 1.0%. It is added to increase hardenability and to elevate temperature strength.

Nickel. Nickel is added to steels to increase their hardenability. It performs well in this function because it often improves the toughness and ductility of the steel, even with the increased strength and hardness. Nickel is frequently used to improve steel toughness at low temperatures.

Vanadium. The addition of vanadium will result in an increase in the hardenability of steel. It is very effective in this role, so it is generally added in minute amounts. In amounts greater than 0.05%, there can be a tendency for the steel to become embrittled during thermal stress relief treatments.

Columbium. Columbium (also called niobium), like vanadium, is generally considered to increase the hardenability of steel. However, due to its strong affinity for carbon, it can combine with carbon in the steel to result in an overall decrease in hardenability.

Other alloying elements. Some carbon steel specifications allow additions of certain other elements, but they are not deliberately added. Other specifications might list these elements as a specified addition to the steel, but the addition would be minor in carbon steels. This is why I refer to the welding material supplier and composition of the stock.

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#4
In reply to #3

Re: regarding welding

01/19/2011 3:08 AM

Hello, thanks for your informative, metallurgist insight-fullness. One of the problems I am needing to solve with an experimental Manganese electrode which boasts or offers a supposed 120ksi tensile strength. Under load tests these new experimental electrodes have induced cracking. Breakage occurs rampantly with this type of metallurgy of Manganese alloy content being increased, even though the MFG says otherwise, any idea why this is? I have been testing these extensively and they are smooth running... These were sent to me by a couple of manufacturers anxious to have me certify and brand them. Even though the welds may turn out beautiful in performance and appearance, such not always holds true. The base metal is typical Dozer or Excavator forged or work hardened metals which typically is welded with much lower tensile strength 7018 type electrode. Under typical old school application; a positive electrode, Miller, Lincoln or Hobart GenSet Welder set to reverse polarity, 5/32, 175 - 250 Amps, 7018 Excaliber electrode typical. This offers marginal strength with low incidence of initial cracking but soon work hardens and fails. Results, weldment fails under loading creating a hazard out in the field, requiring follow up repairs. Solution, a simpler remote welding process offering a higher metallurgy purity and mechanism to homogeneously blend ionized metals and allow crystalline structural formations to freeze together without impurities or stress fractures to occur during and within the entire welding process and cool down. ArcJetWeld is under continual development and is open to any constructive suggestions or feature design requests. An simple design which its feedback process gets excited and or started up off industrial batteries or Cap Batteries and future Firefly Technology. A simpler yet robust welding process at maximum reliably at the lowest cost, offering proven results which speak for itself. Saves time, space and money as an alternative emergency welding device should. Not really a production welder; its forte is emergency remote repair. As time, market, technology and entropy increases, I believe my device will fill order nicely. It has already found its niche and is beginning to replace such huge and overpriced cumbersome welders out there with stronger results in an amazingly compact form. As a small business I have limited resources and appreciate any proactive optimistic or helpful input... More detailed specs will appear online. I have just been buy welding and testing new areas. Stay tuned for my new electrode holder it will light your fire if welding is your passion! My patents are easily searchable. Thank you for everyones interest! Best, C. Tyson Fisk Owner / CTO of http://www.arcjetweld.us/

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