Effect of Carbon Content on the Microstructure and Mechanical Properties of GH3230 Alloy Formed by Laser Melting Deposition

Abstract

Optimizing alloy composition is an effective way to improve the microstructure and properties of superalloys. Herein, the influence of carbon content (0.071, 0.105, and 0.136 wt%, respectively) on the microstructure and mechanical properties of GH3230 alloy formed by laser melting deposition is investigated. The results indicate that the carbon contents affect the quantity, morphology, and distribution of carbides in the matrix of the alloy. As the carbon content increases, the number of carbides increases, and the morphology of the carbides at the grain boundaries changes from discontinuous blocks to chains, and finally into strips. Three alloys with high plasticity at room temperature, and the maximum elongation close to 60% is achieved for alloy containing 0.105 wt% C. The high‐temperature elongation of the alloy also increases at first and then decreases with the carbon. It is therefore concludes that the optimized carbon content is 0.105 wt% by combining both the strength and plasticity for GH3230 alloy prepared by laser melting deposition.