Stainless Steel Wire

It is also important to note that while AWS provides chemical composition requirements for the finished product, there is no system of monitoring or policing compliance. For some applications, meeting the requirements of the industry for which the application is being produced may be more important than conforming to AWS standards. These industry standards include American Bureau of Shipping (ABS), U.S. Military Requirements (Mil), lIoyds, Bureau Veritas and American Society of Mechanical Engineers (ASME).

The second method of alloy analysis and control is by controlled chemical composition. In this scenario, every coil of incoming rod (typically 2,500 to 4,500 pounds of raw steel wire) is tested twice by the electrode manufacturer for chemical composition before being put into production. In this way, the properties in specific coils of steel are matched with qualities that are desirable in specific electrodes and the steel is put into electrode production accordingly. When compared with the heat certification method, this method carries the capacity to allow for additional consistency in chemical composition.

Also, during the continuous casting of steel, segregation of elements occurs in the ladle from bottom to top as the heat is being cast. Typically, the end of the heat (top of the ladle) will contain steel that has an accumulation of residuals and elements that are not indicative of the rest of the heat. Because a heat certification is an average of the start, middle and end of the heat, there is some probability that material in the heat may contain steel that does not meet A WS requirements. In addition, as different orders are melted at the mill, materials with different chemical compositions can get mixed together. This transition material can alter sometimes significantly the nature ofthe steel.

Here's something to consider: There are two methods of alloy analysis and control recognized by AWS A5.01. The first, and most common, uses lot control by heat number. A typical heat certification relies on a small sample taken from a heat of molten steel. The resulting heat certification indicates that the chemical composition of the heat of steel is within AWS specifications for its intended use. The problem is that this small mill test sample represents the chemical composition of a huge quantity often 250,000 Ibs. of molten steel.

Be sure to select a wire with consistent chemical composition. Why? Consistent chemical composition results in more consistent performance. Consistent performance will result in greater, more stable quality control. Your operators and weld engineers will more likely be able to set and forget their procedures, rather than re-adjusting to accommodate wire with wildly fluctuating chemical composition.

The Importance of Chemical Composition

During wire manufacturing, care must be taken to avoid abrupt diameter and cast changes where wire ends are joined together by butt welds. These manufacturing butt weld locations within your wire spool or reel can often cause significant variation in the wire diameter or cast on lesser quality MIG wires. Wire diameter variation over time, even within the AWS specification range, can also affect weld deposition by as much as eight percent. One way to manufacturers can ensure wire diameter consistency and increase your weld quality is to inspect 100% of the wire using laser micrometer inspection methods.

Consistent wire diameter is critical to ensure proper current passage from the contact tip to the wire. Undersized wire causes arcing between the wire and the inside diameter of the tip, which erodes the I.D. of the tip and eventually fuses the tip to the wire. Oversized wire causes excessive feeding force, tip blockage, wire slippage and downtime.

The Effect of Wire Diameter

Selecting a quality MIG wire is critical. It can bernore forgiving and produce a sound weld even under less than perfect conditions. Take, for instance, a plate with surface contaminants. The right MIG wire for that application may make some pre-welding operations obsolete. And, as more companies move to robotics, a quality MIG wire will provide accuracy in wire placement and consistency in the weld, making rework less of an issue.

In fact, when examining the total cost of welding, the cost of the wire is often as low as as approximately four percent of actual welding costs, while the bulk of costs are overhead and labor. So, saving a penny on the price of the wire in the end may actually cost a company much more in productivity-robbing activities that otherwise could be avoided.

Because welding can be a significant fabrication activity for many companies, it is usually one of the first manufacturing processes to receive careful scrutiny when cost cutting is the goal. Unfortunately, many manufacturers think that switching to a lower cost MIG wire will be the silver bullet to boost the balance sheet. In reality, an inferior MIG wire could translate into additional dollars spent in pre- and post?weld operations such as cutting, forming, surface and joint preparation, pre-heating, cleaning, tacking, grinding and painting.

Offshore competition, the increased cost of raw materials, higher energy rates and elevated transportation costs. . . these are just a few of the issues today which are forcing manufacturers to take a hard look at ways to reduce costs and ultimately improve the bottom line.

SELECTING A MIG WIRE TO BOOST YOUR BOTTOM LINE

Type 430 stainless steel filler metal is ideal for 430 base materials because it matches these stabilized grades. CF-8C is the cast equivalent of 430. Type 430 filler metal is also suitable most 308L filler metal applications.

Use 309L (including ER309LSi) when joining mild steel or low alloy steel to stainless steels, for joining dissimilar stainless steels such as 409 to itself or to 304L stainless, as well as for joining 309 base metal. CG-12 is the cast equivalent of 309. Some 308L applications may be substituted with 309L filler metal, but 316L or 316 applications generally require molybdenum and 309L contains no molybdenum.

316L (including ER316LSi) filler metal should be used with 316L and 316 base metals. CF-8M and CF-3M are the cast equivalents of 316 and 316L, respectively.

308L (including ER308LSi) is predominately used on austenitic stainless steels, such as types 301, 302, 304, 305 and cast alloys CF-8 and CF-3. For high temperature applications such as in the electrical power industry, the high carbon 308H electrode provides better creep resistance than does 308L.

When should I use 308L, 309L or 316L,430L filler metal?

Filler Wire (TIG & MIG) MIG Wire dia from 0.800 mm to 1.60 mm in weight spools 12.50 Kg.apx.

KEl's Stainless Steel Wire for Welding Electrodes Wire are manufactured having excellent mechanical properties, under strict guidance of technical people, diameter from 1.60mm to 5.00mm in Matte & Bright finish and can supply in coil as well as in cut length. The commonly manufacture grades are AWS ER 308, ER308L, ER309L, ER31 0, ER312, ER316, ER316L.

WIRE FOR WELDING ELECTRODES