GH4169 high-temperature alloy cast ingot forming method

Abstract

The invention relates to a GH4169 high-temperature alloy cast ingot forming method, which is characterized in that a GH4169 alloy oversized cast ingot is prepared by a laser casting additive manufacturing method, and the GH4169 alloy oversized cast ingot comprises the following average chemical components in percentage by weight: 52.5% of Ni, 19.0% of Cr, 5.13% of Nb, 3.05% of Mo, 0.9% of Ti, 0.5% of Al, 0.05% of C, 18.87% of Fe. The forming laser power is 280-290 W, the scanning speed is 950-970 mm / s, the scanning interval is 79-81 [mu]m, the layer thickness is 39-41 [mu] m, and the interlayer rotation angle is 17-25 degrees. The alloy matrix is a gamma phase, no obvious precipitated phase exists in the crystal and on the crystal boundary, intracrystalline dendrites are fine, and dendritic segregation is mainly the Nb element. The GH4169 alloy cast ingot obtained through the additive manufacturing forming method is low in segregation coefficient, and compared with a traditional cast alloy, cogging can be directly conducted without homogenization heat treatment. The cogging deformation activation energy of the alloy is lower than that of a traditional cast GH4169 alloy, cracking is avoided in the cogging process, and the excellent cogging performance is achieved.

Description

technical field [0001] The invention belongs to the field of high-temperature alloys, and in particular designs a method for forming super-large-diameter GH4169 high-temperature alloy ingots. Background technique [0002] At present, GH4169 is a precipitation-strengthened nickel-based superalloy with good comprehensive properties in the temperature range of -253 to 650°C, good yield strength below 650°C, and good fatigue resistance, radiation resistance, oxidation resistance, and corrosion resistance. Corrosion performance, and good processing performance, welding performance is good. It can manufacture parts with complex shapes, and has been widely used in the above temperature range in aerospace, nuclear energy, petroleum industry and extrusion dies. [0003] The GH4169 alloy smelted by the traditional method has a coarse dendrite structure, and the dendrite segregation is serious, which makes homogenization difficult, but homogenization treatment must be done to eliminat...

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Problems solved by technology

[0003] The GH4169 alloy smelted by the traditional method has a coarse dendrite structure, and the dendrite segregation is serious, which makes homogenization difficult, but it must be homogenized to eliminate dendrites

Moreover, the precipitated phase of the alloy is complex. There are Laves phase, MC carbide, and δ phase in the as-cast GH4169 alloy. After homogenization heat treatment, although the Laves phase can be eliminated, it will cause the δ phase to grow back and dissolve, especially the grain structure. Coarse, reducing the recrystallization ability of the alloy during billeting

The segregation degree of the core and the edge of the traditional GH4169 ingot is different, and the segregation degree of the core is relatively high. In order to fully homogenize the core during heat treatment, it will cause the precipitation phase at the edge to grow or melt back, and will also reduce the blooming of the alloy. performance

like figure 1 The GH4169 alloy prepared by the traditional casting method has thick dendrites, developed secondary dendrite arms, and a large number of precipitated phases between the dendrites, including granular Laves phase and needle-like δ phase, which is not conducive to the casting performance of the alloy.

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