Climax AUTOBOREWELDER BW3000, Руководство по эксплуатации

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P/N 52815, Rev. 7 Page 73
In some cases, laminated sections in heavy equipment bores can have grease
deposited in the spaces between the layers. You have a few options to handle this
problem. You could pre-grind the lamination line, and pre-weld with stick welding
rod to seal the lamination. This is very effective, but is time consuming and diffi-
cult on small bores. You could preheat in an attempt to drive out the grease. How-
ever, it’s likely that grease will continue to leak out while welding continues. It’s
also possible to weld up to the lamination, stop the weld process, retract the
machine over the lamination, and restart the weld process. The unfinished section
can then be stick welded after borewelding is complete.
5.3.1.8 Steel weld deposit is too hard to machine
Assuming the wire is a mild steel wire (such as the 70s-series), the ability to
harden must be attained from the base material. If the deposit is hard, it must have
obtained carbon and possibly other alloys from the base material which cause it to
be susceptible to heat treatment hardening.
Generally, to prevent hardening, slow down the cooling rate. To do so, increase the
preheat of the part and/or decrease the rotational travel speed of the torch. Fast
travel speeds produce a rapid quench of the weld beads.
If hard weld beads are encountered, you may be able to temper the hardened bead
by welding another pass directly over it.
If the buildup is still too hard, post-heat to a temperature of about 1,100°F (593 °C)
to temper the weld bead and allow machining.
T
IP
:
Allow the part to cool to less than 400°F (204°C) before reheating. Do
not allow any part of the weld to rise above the critical temperature
(about 1,300°F [704°C]) even for a short time, unless you are prepared
to do a full anneal with the associated heat soaking and slow cooling.
5.3.1.9 Weld breaks cutting tools when machined
A tungsten carbide tool bit edge can be “honed” to make it less susceptible to
breakage. If you create a 45 degree chamfer that is 0.005–0.007" wide (0.127–
0.178 mm), the toughness of the tool bit is increased.
5.3.1.10 Weld “graping”
Graping occurs when the molten puddle overcomes the surface tension that holds
it in place. The term “graping” refers to the drooping globs of weld metal hanging
from the bore surface.
Typically, this occurs on the uphill section when the BoreWelder is in the horizon-
tal axis.