tube to tube sheet welds and repairs are sectioned etched and evaluated at 60 u00d7 to check for ddc and any further signs of hot cracking 3 to evaluate root cracking a solid plate of inconel alloy 690 is welded along one side of the weld overlay with a standing edge weld to simulate tube to tube sheet welds this weld is sectioned polished etched and observed at 60 u00d7 at various locations along its length to check for root cracking tendency 4 standard u215c inch thick transverse side bends are also cut from the weld overlay and are bent 180 u00b0 around a 2t mandrel the outer surface of the bend which has been elongated approximately 20 is then examined for bend cracks or u201c fissures u201d with the number of fissures and size of fissures being recorded per bend a series of weld deposit chemistries are shown in table 1 below each weld deposit chemistry is comprised of approximately 30 cr 58 ni 8 fe with varying amounts of nb mn and other minor elements an abbreviated reporting of the foregoing tests is tabulated just below each composition in the table the table and results are somewhat self explanatory but examination of boron and zirconium vs ddc or cold cracking reveals that without either or without both cold cracking occurs with regularity while with boron contents of about 0 0005 to 0 004 and zirconium of about 0 0003 to 0 02 cold cracking is avoided it will also be noted that with sufficient levels of nb and mn coupled with proper control of other minor elements hot cracking is avoided an additional advantage of boron and zirconium additions with improved nb and mn levels is that al levels may be.