ENHANCING LIFE OF FORGING DIES

Forging is one of the most important manufacturing processes for steel products. The cost of forging dies is the critical variable that decides the cost of forged products. These costs can be reduced by extending the life of forging dies and by minimizing the use of costly die steels.A Forging diel is made of medium carbon low alloy steel with Cr, Ni, Mo, V, W alloy additions. They are AISI H11, H12, H13 type air hard enable Tool steels, DB6 steel DIN 1.2714 and are expensive hardened and tempered die steels. The die surface wears out gradually due to the combined effects of impact and friction during service and needs to be rebuilt by overlaying to re-establish its profile and thereby extend its life.

Die wear occurs due to a combination of following phenomenon:

• Wear due to abrasion

• Thermal fatigue

• Mechanical fatigue

• Permanent deformation

Merits of Die Life Enhancement:

• Extends the life of forging dies

• Enhances their performance

• Saves time.

• Drastically reduces die set inventory carrying costs.

• Reduces operating costs.

There are mainly two types of dies used in forging industries:

• Drop or Hammer Dies

• Press Forging Dies

Hardness requirement for these dies are 40 HRc and 50 HRc respectively.

AWL offers a reliable welding electrode NIMOTEN PLUS 535 B, a Cr-

Ni-Mo alloyed electrode which meets 40 HRc hardness requirement of

drop forging dies. 

It is used to repair and recondition defective and

worn out dies.

High deposition rate is achieved using large size electrodes. 

There are two methods for Die repair:

Overlay Welding: It is a technique of laying weld material on the die

impression instead of complete flood welding. It is applied to overlay

on shallow wear depth.

Flood Welding: A large amount of welded material is deposited onto

the area to be welded. Die blocks that are imprinted and have become

obsolete can be reclaimed for reuse by flood-welding.This method is

particularly suitable for repairs on large dies.

AWL offers a reliable welding solution with-

NIMOTEN PLUS 535 B

 i)   Cr-Ni-Mo alloyed welding electrode
 ii)  Meets 40 HRc hardness requirement of drop forging dies
 iii) Used to repair and recondition defective and worn out dies

 iv) Available in 5.0, 6.3 mm sizes

AUTOMIG FC 400 

 i)   Cr-Ni-Mo alloyed flux cored wire
 ii)  Suitable with 80Ar+20CO2 shielding gas
 iii) Best suited for multi pass crack free welds
 iv) Hardness 40-42 HRc

 v)  Available in 2.4 mm diameter

Welding Procedure using Nimoten plus 535 B(please click for product details):

•Remove all cracked and worn out areas.

• Carbon arc gouging is mostly used after the dies have been suitably preheated.

• Make sure that sound surface has been reached.

• Preheating in a furnace for uniformity throughout the die.

• Use of asbestos cloth / glass wool / ceramic blank etingto maintain preheating, reduce the cooling rate and to keep interpass temperature within the required limits.

• After each weld pass but while the weld is still hot, the slag to be removed and peening is required. Peening by pneumatic hammer to reduce residual stresses.

• Reheating in a furnace to 540°Cto reduce local thermal gradients and slow cooling to room temperature.

• Final PWHT for stress relieving and tempering must be selected according to the materials involved and must be applied with care.

• Machining as per forging profile

Correct heat treating is the essential factor for successful repair welding.

JOB DETAILS
Component	Piston Die(Top and bottom)
Quantity	2 nos.
Die Material	DB6 (DIN 1.2714)
Hardness	38-42 HRc
Depth of Wear	Up to 5 mm
Welding Parameters:
Product	NIMOTEN PLUS 535 B
Size, mm	4.00
Current, A	160-170
Preheating	400 ◦ C
Welding Method	Overlay Welding
Die Life:
Earlier Die Life	<2000 nos.
Forging Die Life after rebuilding	2150 nos. 150 more than the nearest competitor's brand

For more information on the above please get in touch with cmo@ adorians.com  also you can give us your feedback on www.adorwelding.com(please visit our website)

e-Weldone Newsletter - July 2013 (Volume 46)

IMPROVING PRODUCTIVITY WITH TUNGSTEN INERT GAS (TIG) WELDING Introduction TIG welding is a relatively slow process by its nature such as the welder having to synchronize the flow of shielding gas with the feeding of filler wire. But it is also a very versatile process, as it can be used to weld more materials than with any other welding process, including non ferrous, exotic and heavier alloyed metals. It is also ideal for thin materials, as it generates low heat input to prevent burn-through. Plus, no matter the application, when done properly TIG welding can provide extremely high weld quality. Achieving such positive results is not always easy and requires great effort and skill, compared to manual arc welding. With the help of few tips and by following certain methods one can improve the efficiency in the TIG welding process. After all, nobody wants an already slow welding process to become slower! Some procedures to increase productivity with the TIG process are described below. Use of Inverter TIG power source: Using an inverter power source is one of the first steps to improve TIG welding efficiency. Inverters operate at very high switching frequency up to 50 KHz which converts high AC input supply voltage to low TIG welding DC voltage. The overall result is a smooth arc that provides consistent welding performance. Inverters also have frequency controls that allow welders to adjust the frequency from 20 Hz – 400 Hz. (transformer-based power sources only produce an output of 50/60 Hz, which is the same frequency of input mains supply voltage available from Electricity Board).The inverter’s frequency control feature helps improve welding efficiency by narrowing the focus of the arc, which in turn creates a narrower weld bead and minimizes the heat-affected zone. With this feature, you will need less time and filler metal to complete the weld and can also obtain faster travel speeds. Due to reduced heat-affected zone, it minimizes the chance of burn-through and the need for rework, which is a definite cost saver in any welding application. Inverters also have a feature of balance control, which allows welders to adjust the time the current spends in each part of the AC cycle and is especially useful if welding aluminum. Balance control can be adjusted toward the electrode positive part of the cycle to gain more cleaning action (removal of the oxide layer) or toward the electrode negative to gain greater weld penetration and faster travel speeds to finish the job sooner. Use of suitable TIG torch: Selecting the right TIG torch for a particular application can also help to make the process more efficient. The torch should be provided with good insulation to avoid high frequency leakage and/or cracking and to avoid premature torch failure and downtime for torch changeover. Silicone rubber is a good insulating and heat resistant material which can be used for this purpose. Efficiency also depends on whether an air- or water-cooled TIG torch is to be used. Air-cooled models can be used on low amperage applications, or those applications where current to be used is below 200 amps. They are the best option if you are welding very thin materials, under 5 mm, and/or need to be able to move from one area to another easily, as they do not require an external cooling. Water-cooled TIG torches can be considered for applications where current to be used will be over 200 amps. This type of torch helps prevent overheating and allows operator to achieve faster travel speeds which ultimately provide more weld deposit in less time. When selecting a TIG torch, also consider the angles of joints that need to be welded, since maneuvering around difficult joints can be time-consuming and uncomfortable. Most TIG torch manufacturers offer models with flexible necks that are convenient for welding in particularly tight joints or awkward positions. Some torch body styles also feature a modular design, which allows addition of a flexible neck and different head angles to an existing torch. These kits provide good joint access and can lower downtime associated with changing over to different torches for multiple applications. Plus, one can save money on extra inventory. Use of gas lenses: When possible, use a gas lens. A gas lens replaces the collet body in a TIG torch to help hold the tungsten in place and creates the electrical contact necessary for proper current transfer. It also provides two other functions which help to improve efficiency: it improves shielding gas coverage and provides better joint accessibility. Gas lenses typically comprise of a copper and/or brass body that contain layered mesh stainless steel screens. These screens distribute the shielding gas evenly around the tungsten electrode, along the weld puddle and the arc to help prevent oxygen contamination that could lead to weld defects. Hence welder can spend more time on welding rather than on rework , which lower weld defects and thus increase productivity. Gas lenses also allow operator to extend the tungsten electrode further out from the nozzle. This additional electrode extension provides better visibility of the joint and arc, which gives greater torch control and achieve better weld quality especially on critical applications and/or hard-to-reach areas such as “T”, “K” and “Y” joints. Gas lenses are particularly helpful when TIG welding alloys that are highly reactive to atmospheric contaminants or welding materials which are used in high temperature applications. They can also be used with all types of shielding gases and are available for both air- and water-cooled TIG torches. Avoiding Overwelding: Avoiding overwelding can significantly improve the TIG welding efficiency and it can save the money, as well! Overwelding occurs when more weld metal is deposited in a joint than required to obtain the necessary weld strength. Depositing more weld metal is a result of poor joint-fit up or preparation, improper weld parameters. Overwelding, unfortunately, wastes shielding gas and filler metal, and it increases welding time. In addition, overwelding increases the heat input into the base material and with it raises the risk of burn-through or distortion that will require costly and time-consuming rework. It may even increase the need for grinding and finishing. To prevent overwelding, ensure that joints are not larger than necessary to gain the appropriate strength for the application. A good rule of thumb is to make the leg of a fillet weld no wider than the thickness of the thinnest plate and weld accordingly. For example, when joining a 3mm thick plate to a 6mm one, it only needs a 3mm weld bead. Proper joint preparation and close fit-up are also good defenses against overwelding, as is welding vertical down on thinner materials. Use of suitable tungsten electrode and its shape: Selection of type of tungsten electrode depends on the kind of power source, as well as on the welding material, but it can have a significant impact on efficiency of welding. So can the shape of the tungsten electrode. For AC and DC welding using an inverter, a pointed and/or truncated tip (for ceriated, lanthanated and thoriated tungsten) provides the stable arc needed to achieve good welding performance and quality. To achieve this shape (and to prevent contamination or arc wandering) grind the tungsten on a borazon or diamond grinding wheel specially designated for the purpose. Next, grind the taper on the tungsten to a distance of no more than 2.5 times the electrode diameter (for example, with a 3mm electrode, grind a surface 6 to 8 mm long), as this eases arc starting and helps creates a more focused arc. When welding with lower amperage on thinner materials (those ranging from 0.125mm- to 1.0 mm.), it is best to grind the tungsten electrode to a point. A pointed tungsten electrode allows the welding current to transfer in a focused arc and helps prevent distortion. Pointed ceriated tungsten electrode, in particular, works well when welding aluminum, as it provides 30 to 40 percent more current capacity than pure tungsten before it begins to melt. As a side note, do not use a balled tungsten electrode for such an application. On higher current applications, grinding the tungsten to a truncated tip can help the welding performance by preventing the tungsten from balling. First grind the tungsten electrode to a taper as explained above, then grind a .25 mm- to 0.8 mm flat land on the end of the tungsten electrode. Use of cold TIG wire feeders: For long weld runs where filler wire is used for increasing the weld metal deposition, then continuous feedingmechanism will be helpful to improve the efficiency of total welding operation. In such feeding system, filler wire in the form of spool is fed by the wire-feeder and mechanical arrangement for wire guiding is mounted on the TIG torch. The main components in this wire-feeder system are the mechanical drive units, the electrical control systems and the wire guiding parts up to the welding arc. This semi-automatic cold wire-feeder increases TIG welding productivity by eliminating time-consuming arc “stops-and-starts” common with cut-length-rod. It saves 20-40% on filler metal costs because spooled-wire is less expensive than individual cut-length rod, and the unused rod end wastage is eliminated. It reduces process variables with continuous spooled-wire which provides quick and consistent filler metal reliability eliminating the potential weld quality problems associated with unidentified welding alloys. Conclusion: Although TIG welding is a slow process, by having some know-how and a bit of practice, it can become more efficient. With help of proper selection of equipment and accessories and taking care about the size of the welds, welding efficiency will improve which in turn will save money in the long run. Ador Welding Ltd. manufactures and supplies a wide range of TIG welding equipment. Please visit www.adorwelding.com to know about this range. Please also contact cmo@adorians.com for guidance in improving productivity as well as advice with TIG welding applications. An  electrode to deposit air hardening type of weld metal having hardness in the range of 330-380 BHN approx. Weld metal is machinable with carbide tools. Excellent arc stability and low spatter loss. All sizes strike and re-strike easily . Weld beads are smooth, uniform and of excellent appearance. read more AWS A/SFA 5.4 E 308-16 A 19/10 electrodes with controlled Ferrite content of 3 to 7% for maximum resistance to cracking, corrosion and high temperatures up to 8000 C. The weld metal has excellent creep strength and is of radiographic quality. Excellent arc stability and low spatter loss. All sizes strike and re-strike easily. The slag is easily controlled and does not interfere with the arc action. Weld beads are smooth, uniform and of excellent appearance. read more Inverter based GMAW process welding outfit Digital Panel for adjusting the welding parameters 30% more Energy efficient than conventional machines. Maximum Power factor is 0.94 Excellent dynamic response enables superior arc characteristics. 2T, 4T operating modes Electronic choke adjustment for better arc control Crater voltage and Crater current adjustment through digital panel. Unique feature of Fresh Tip Transfer (FTT) to avoid globule formation. Automatic “Weld Stop” facility. read more INVITATION AdorWac Alumni Association (A Cube) Ador Welding Academy – Placement Services Ador Welding Academy (AWA) Certification Course for Welding Inspectors (QC-1)  5 to 9 August 2013 Quality Assurance & Control of Welding (QA-I)  2 to 5 September 2013 Welding Procedures and Qualification (QA-II)  23 to 25 September 2013 GTAW for Arc and Gas Welders (AWC-1)  26 to 30 August 2013 Tube & Pipe Welder Certification (ASME SEC.IX) GTAW+SMAW PROCESSES (AWC-1Q)  2 to 13 September 2013 Pipe Welding(6 G) (AWC-7Q)  19 to 30 August 2013 SMAW & OXY FUEL WELDING/ Cutting (WD-1)  2 to 27 September 2013 Baseweld - SMAW for Beginners (BW-1)  5 September to 25 October 2013 IBR Plate Welder certification by SMAW PROCESS (AWC 6Q)  2 to 6 September 2013 NDT LEVEL - II - ( PT ) (QC-NDTLEVEL-II)  26 to 31 August 2013 Join Us

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e-weldone Newsletter - Feb 2013

EFFEICIENT WIND TOWER MANUFACTURING Introduction One of the established sources of renewable power is wind energy. With the growing demand for wind energy, the demand for wind towers also increases. The challenge for wind tower producers is to build towers to client specifications in the most efficient and profitable way. The requirements for towers for on shore and off shore are nearly similar, except for steels for offshore applications where extreme temperature requirements are to be met. Welding is the most widely accepted practice to build wind towers. This article provides insights into requirements for increasing productivity of tubular wind towers. The design sets the rules for production The design, choice of material and material thickness determine the required welding and cutting solutions The height of the tower determines the number of shells to be fabricated Weld geometries need to be designed for fast production 1. The joint types Joint types vary with plate thickness to obtain optimal strength at the lowest weld volume. 2. The production flow Cutting and welding are two important steps of a series of steps in the production of a wind tower. A standard flow lay out is described below and some details of the various steps are given thereafter. 3. Cutting With  modern cutting machines and software, steel plates are perfectly cut and prepared in a reliable and accurate process High quality bevelling is crucial for successful welding All sides of the same plate must be bevelled for the  joint preparation Bevel types per side may differ, for example for joints with different material thickness tapering is adopted. This design also reduces stress concentration at the joint (refer figure below). 4. Rolling and forming Cut and bevelled plates are rolled into conical shapes (above) and tack-welded (described in 6 below). 5. Welding Welding is a major time factor in the production of a wind tower and comprises of tack welding, longitudinal welding and circumferential welding. The cost of welding is a small part of the total costs Investing in efficient automated welding solutions increase productivity substantially 6. Tack welding 7. Longitudinal welds After tack welding, longitudinal joints are welded with the submerged arc welding process, both on the inside and outside. This can be done in a separate station or in the same station, where the circumferential welds are also carried out. Two popular practices adopted for longitudinal welding are described below. (i) Growing line principle (ii) Added lines principle 8. Longitudinal welding station 9. Flanges 10. Fit-up 11. Circumferential welds 12. The door frame 13. Blasting & painting After the shells are welded, blasting and painting are essential to preserve the tower in the field 14. The tower segment The production results are: High quality welded wind tower segments Produced with safe and ergonomic equipment Solutions that enable high productivity. Ador Welding Ltd. support The welding and cutting solutions come with valuable support and commitment to allow customers to reach their full potential: Training at all levels In-depth seminars with the industry experts Productivity audits Establishment of welding procedures Please contact cmo@adorians.com for assistance in selecting welding equipment (MMAW/ SAW/ FCAW/ Automation Systems) and consumables, cutting equipment as well as training of engineers/ welders for maximising productivity in wind tower fabrication. Indigenous inverter based Pulse TIG DC welder Three phase inverter based, High efficiency and High Power Factor Pulse TIG/ MMA DC Welder Useful for wide variety of material types and thickness. read more Inverter (IGBT) based energy efficient welding rectifier Inverter (IGBT) based, energy efficient welding rectifiers for heavy duty structural welding applications High power factor, high efficiency resulting energy savings up to 35% over thyristorised rectifiers read more    Low Alloy High Tensile Electrodes read more Service Clinics During the Month ofJanuary2013 SHREE CEMENT LTD UNIT I BEAWAR- JAIPUR AO - JAIPUR - 11 NOS. SHREE MEGHA POWER BEAWAR- JAIPUR AO, JAIPUR - 13 NOS. ESSAR STEEL (I) LTD –BLAST FURNACE UNIT HAZIRA, SURAT-AHMEDABAD AO, AHMEDABAD - 15 NOS. Ador Welding Academy (AWA) A Cost Effective Model to Create New Welders and Upgrade Skills of Existing Welders Join Us

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