CMT-Pin Additive Preparation of GH4169 High Temperature Alloy Columnar Array Forming Process and Microstructure

Using Phi(1.2) mm ER-GH4169 welding wire, the columnar array structure was prepared on Q235 carbon steel substrate with 5 mm in thickness by CMT- Pin additive technique, and the Pin forming process and tissue characteristics were investigated. Results show that when the Ball/Cyl adaptation parameter is negative, the Pin head shape is cylindrical; when the Ball/Cyl adaptation is non-negative, the Pin head shape is ball. The altitude adaptation controls the height of Pin growth, and the Pin height is 2.30-4.96 mm. The microstructure of Pins is divided into Pin axis zone, fusion zone, and base material zone. Pin axis area has a large number of columnar crystals, which grow outward along the axis. In the fusion area, the columnar crystals change from fine crystals to coarse crystals along the upward Pin axis, and the fusion area is a very fine fusion line with a large number of strips of Laves phase precipitated between the crystals. The tissues of light and dark interlayers exist in the base material area.