HERCULCK

4465 Kent Avenue, Niagara Falls, Ontario, Canada L2H 1J1

Tel (905) 354-3875 Fax (905) 354-6384

E-Mail Herculock@ont.net

Welding and Brazing

A welding service is available for a variety of processes and materials. In addition, we can be consulted regarding welding materials, performance records prove beyond a doubt that, crankshafts repaired by welding last as long - and usually longer - than new shafts, yet cost an average of 40-60% less to repair than a new replacement. Furthermore, the biggest single factor with which most plant engineers are concerned is the amount of downtime lost. Again, records prove that repairs cut downtime an average of 50-80% over the time it usually takes to get replacement parts. 
For example:
· Most 4" to 5" shafts we repair each year are completed within three to four days
· Larger 10 ton units, with twenty-five inch diameters, may take from two weeks to a month [unless urgently needed]
 

PRE-INSPECTION REQUIRED
Before welding any part, whether it is a crankshaft or some other object, a plant engineer inspects it thoroughly for fatigued and cracked areas. These areas are "veed" out with a cutting torch, and preheated. These "vees" are filled with a low hydrogen electrode containing 1.75 to 2.25% manganese and .30 to .60% molybdenum. Molybdenum was developed specifically for welding high tensile steel to have a higher hardening ability. In fact, the welded areas have a higher tensile strength than the original steel.
 

Ratings for the tensile strength range from 105,000 to 110,000 psi, with a minimum yield point of 94,000 psi. Stress relieving performed at 1150°F alters these values to 103,000 to 106,000 psi tensile strength, and the psi yield strength is 90,000 to 95,000 psi. The results are that ductility is excellent; elongation is between 18 to 23% for a two-inch section; and stress relief of the metal is increased by 19 to 24%.
For the annealing process, we put the steel portion in the furnace at temperatures ranging up to 1500°F. Parts remain in the furnace for about one hour per inch of diameter. Before annealing, however, all machine surfaces in the reworked areas, are built up 1/4" in diameter to facilitate re-machining. By annealing in this way, all stresses in the part caused by past use or welding are removed; and grain structure is restored to its normal state. The same procedure is used on all forged and cast steel parts such as connecting screws, back shafts, rocker shafts, gears, frames etc.
If no machining is necessary, many jobs can be done right in your shop, which saves you from additional expense and downtime. For further information, please contact us at your convenience at E-Mail Herculok@ont.net

PROPER BRAZING TECHNIQUES

Brazing, especially as used in Industrial Welding & Brazing for the repair of most iron casting, is an extremely complex operation. The correct preparation of cast iron for brazing is vital to the success of the braze.

First, a casting is "veed out" by the use of chipping hammers or machines. These methods are used because they permit the surface to be cleaned and readied so that the brazing doesn't burn the grain structure. If the casting is in two or more pieces, they are aligned and tack welded together, then pre-heated to a steady temperature of 800 to 900 degrees. This prevents stresses that would be set up by localized heating. While the brazing is being performed, torches bring the temperature up to 1200 degrees - the temperature at which bronze will best fuse with cast iron. Under these conditions, the bronze will 'sweat' approximately 1/8 inch into the pores of the iron, thus forming a strong bond.

The result is castings brazed without excess build-up have double the strength of the original cast iron, while castings brazed on a non finished surface with additional build-up will develop up to three times the strength of the original casting. Finally, brazing itself has a high tensile strength and good machine ability.

A few of the parts that are repaired by brazing are cast iron rams, press frames, bases, connecting links, crowns, gears, knuckles, air cushions, housings and many other. Under certain conditions, brazing can be performed on a casting on-site, without removing it from the machine.

The repair of cast iron parts by brazing usually results in a saving to the customer in two ways; considerably less downtime and less actual cost as compared to the price of a new casting. You also get our guarantee of quality workmanship.

Before and after photos of 100 ton Press repaired by Brazing.