Production method of fine-grain high-strength GH4169 alloy by hot rolling

Abstract

The invention discloses a production method of a fine-grain high-strength GH4169 alloy by hot rolling, belongs to the technical field of production techniques of high-temperature alloy rods for aerospace. According to the method, a roughly rolled blank is subjected to a conventional production process, including heating, rolling, cooling and the like, to produce the hot rolled rod of which the diameter is 20-45mm. The technical key is to implement grain refinement and grain size control by controlling the rolling speed of the continuous hot rolling set (controlling the dynamic and sub-dynamic recrystallization of the rolling process), and to shorten the alloy heating and holding time through an on-line solution treatment technique by inducing the second phase precipitation with deformation, thereby achieving the goals of inhibiting grain growth and solution strengthening. The method lowers the manufacturing cost of the high-temperature alloy hot rolled rod, enhances the strength indexes of the alloy, and provides a new technique for producing the hot rolled high-temperature alloy for aerospace.

Description

technical field [0001] The invention belongs to the field of preparation of alloy materials for aerospace, and in particular relates to a hot rolling production method of fine-grained high-strength superalloy. Background technique [0002] Superalloys are important structural materials in aviation, aerospace and other industries. Among the more than 100 high-temperature alloys that have been developed, GH4169 alloy is the most important deformed alloy (its composition is: Ni: 50-55%; Cr: 17-21%; Nb: 5-5.5%; Ti: 0.75 ~1.15%; Mo: 2.80~3.30%; Al: 0.30~0.70%; C: 0.02~0.06%; the rest is Fe). Since the alloy was successfully launched in 1959, after nearly 50 years of continuous improvement and development, it has become a nickel-based deformation alloy with the largest output and the widest use area, and higher requirements are put forward for the grain size and strength of the alloy. Require. Under the production conditions of traditional tandem mills, grain refinement is main...

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Problems solved by technology

Under the production conditions of traditional tandem mills, grain refinement is mainly achieved through low-temperature rolling and second-phase constrained grain growth, and its main characteristics are low yield, low production efficiency, and unstable quality (Zhuang Jingyun, Du Jinhui, Deng Qun, Qu Jinglong, Lu Xudong. Deformed superalloy GH4169. Beijing: Metallurgical Industry Press, 2006.)

The production rate and production efficiency of the alloy can be effectively improved by hot rolling production, but this production method must be completed at a higher temperature (1050-1100°C) to reduce the energy consumption of the tool

Hot continuous rolling of alloys at the above temperature must solve two problems: 1) Control reasonable heating temperature and rolling speed, so that the alloy can complete the grain by means of dynamic and sub-dynamic recrystallization during the rolling process and intermittent passes (L.X.Zhou, T.N.Baker, Effect of dynamic and metadynamic recrystallization on microstructures of wrought IN-718 due to hot deformation, Mater.Sci.Eng.A196(1-2)(1995)89.); 2) above temperature The complete dissolution of the second phase that inhibits grain growth within the range will lead to grain growth in the alloy during cooling after rolling, subsequent solution heating and holding (Cai D Y, Zhang W H, Nie P L, Liu W C, Yao M. Dissolution kinetics and behavior ofδ phase in Inconel718[J].Transactions of Nonferrous Metals Society of China,2003,13(6):1338-1341.)

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