Preparation of Cracked Areas. - TB-9-2510-242-400059

TB9-2520-242-40

3.1.3 Preparation of Cracked Areas.

CAUTION

Do not use an oxyacetylene torch for gouging or metal removal due to the danger of overheating

the base metal. High heat may result in a serious loss of T-1 material properties. Do not exceed

maximum temperatures shown in Table 2.

a. Remove defective material and prepare joints. Remove old weld material or cracked base metal.

Mechanically grind along the entire length of the crack. Extend the groove beyond each end of the crack, to a

distance equal to twice the base metal thickness. Ensure that the depth of the groove is a minimum of 1/32 inch

beyond the depth of the crack. Removal of material by chipping is acceptable.

WARNING

DO NOT INHALE CHEMICAL AGENT RESISTANT COATING (CARC) PAINT PARTICLES. CARC

PAINT IS TOXIC. USE BREATHING RESPIRATOR WHILE REMOVING PAINT.

b. Prepare surfaces. Remove all paint, grease, scale, rust, water, etc., for a distance of 4 inches around the new

weld area. Remove paint from the back and inside of all metal surfaces to be welded. Use mechanical or

abrasive cleaning methods such as sandblasting, grinding, or degreased stainless steel wire brush.

3.1.4 Electrode Selection. Electrodes used for welding T-1 steel must meet proper tensile strength requirements and

have a low hydrogen content to avoid hydrogen induced cracking. Electrode selection may also vary depending on the

application and welding method. See Table 1 for a list of low hydrogen electrodes and processes which may be used to

weld T-1 steel. The following is a guide for selecting electrodes.

a. Tensile Strength Selection. T-1 steels range in tensile strength from 50 to 150 ksi depending upon their grade

and thickness. The following are general rules for their use:

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