The invention belongs to the field of
nondestructive testing, and discloses a manufacturing method of a multipurpose
nondestructive testing natural defect test block, which comprises the following steps: forming a groove on a base material with the thickness of more than 12mm, and carrying out backing
welding by adopting
argon tungsten-
arc welding, wherein both the base material and a weld joint can be magnetized; filling the grooves of the
base metal through
shielded metal arc welding to complete weld joint filling; in the filling
welding process, making an incomplete fusion defect, an incomplete penetration defect, an air hole defect, a
slag inclusion defect and a
tungsten inclusion defect in the weld joint; determining a designed crack area on the weld joint,
coating ferrous sulfide powder on the designed crack area, and then performing shallow penetration and remelting on the weld joint in the designed crack area;
polishing the remelting area of the weld joint, and
polishing off unmelted
ferrous sulfide; and performing cosmetic
welding on the surface of the weld joint to obtain the multipurpose
nondestructive testing natural defect test block. The manufacturing process is simple, the cost is low, cracks with various defects and that are close to the natural forms are formed, and the training and teaching requirements are met.