Effects of heat treatment on microstructure and mechanical properties of RAFM steel extruded tube

doi:10.13251/j.issn.0254-6051.2025.04.030

Abstract

Abstract: Heat treatment between 780-1200 ℃ for RAFM steel extruded tube with size of ø57 mm×6 mm obtained by double vacuum melting combined with multi-pass hot forging and re-hot extrusion was carried out, and the microstructure and mechanical properties of the extruded tube at different heat treatment temperatures were studied. The results show that after heat treatment between 780-1200 ℃, the microstructure evolution of the RAFM steel extruded tube with increasing temperature is as follows: tempered lath martensite (780-900 ℃), martensite matrix+ferrite+fine dispersed carbides (950-1000 ℃) and lath martensite (1050-1200 ℃). The tensile strength, yield strength and hardness of the RAFM steel extruded tube at room temperature decreases first and then increases with the increase of heat treatment temperature, while the elongation increases first and then decreases. After heat treatment at 850 ℃, the RAFM steel extruded tube obtains relatively excellent room temperature elongation and relatively low strength, which is convenient for subsequent production and processing.

Key words: RAFM steel, microstructure evolution, mechanical properties, hardness

CLC Number:

TG156

Cao Ping, Wang Guobo, Chen Dengwu, Su Cheng. Effects of heat treatment on microstructure and mechanical properties of RAFM steel extruded tube[J]. Heat Treatment of Metals, 2025, 50(4): 207-212.

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