English to Portuguese Tech/Engineering Metallurgy / Casting coating

Although Mr. Klein was able to pioneer an automatic submerged arc welding process to apply the alloy economically, the coating was not without certain drawbacks. First of all, such a hard alloy cannot be welded without creating a pattern of cracks throughout the coating. Though small and nearly imperceptible to the touch once the block is ground, these cracks can cause marking problems for some softer or plating quality wires. Also, the extreme pressures involved in drawing very large diameter wires can sometimes weaken the cracks enough to cause chunks of weld to chip out. To this day, however, the cracked sub-arc weld coating offers the longest working life for all blocks drawing carbon steel wires (up to 5/8" dia.) in dry lubricant. A lesser alloy can be welded without the cracks, but it has limited uses due to its much lower resistance to wear. Sub-arc weld is further limited by the fact that it can only be applied to block walls that are at least 1A" thick, or it will burn through. For blocks that have been cut down too thin, the weld will have to be applied to a steel sleeve that is then shrink-fitted and bolted to the block. The sleeving process more than doubles the cost of the block repair job.