Repair process

A process for repairing at least one crack in a metal workpiece comprising the steps of:

• forming a braze paste containing a first nickel base alloy material containing boron and chromium and a second nickel base alloy material containing chromium and cobalt;
• applying said brazing paste to an area of said metal workpiece containing said at least one crack;
• subjecting said brazing paste and said workpiece to a brazing cycle by heating said brazing paste and said workpiece;
• and
• wherein said braze paste forming step comprises mixing a first nickel base alloy material consisting from 14 wt % to 16 wt % chromium, from 2.4 wt % to 3.0 wt % boron, up to 0.15 wt % total other elements, and the remainder nickel and inevitable impurities and a second nickel base alloy material consisting of from 22 wt % to 23 wt % chromium, from 18.5 wt % to 19.5 wt % cobalt, from 3.5 to 4.0 wt % titanium, from 1.8 wt % to 2.2 wt % tungsten, from 1.7 wt % to 2.0 wt % aluminum, from 1.2 wt % to 1.5 wt % tantalum, from 0.8 wt % to 1.2 wt % niobium, from 0.13 wt % to 0.17 wt % carbon, up to 0.2 wt % manganese, up to 0.015 wt % phosphorous, up to 0.10 wt % copper, up to 0.25 wt % iron, up to 0.10 wt % silicon, up to 0.04 wt % zirconium, from 0.001 wt % to 0.008 wt % boron, up to 0.005 wt % sulfur, up to 0.005 wt % nitrogen, up to 0.003 wt % oxygen, up to 0.0005 wt % silver, up to 0.0005 wt % lead, up to 0.00005 wt % selenium, up to 0.00003 wt % bismuth, up to 0.00005 wt % tellurium, up to 0.00005 wt % thallium, and the balance nickel and inevitable impurities.