The microstructure in the inter-critical heat-affected zone (ICHAZ) of HQ130 steel, has been investigated by thermo-simulation test, SEM and TEM. The problem of toughness decrease in the ICHAZ (𝑇p = 800°C) as well as the effect of M–A constituent and carbide precipitation on brittleness was analysed. The test results indicated that the microstructure in the ICHAZ of HQ130 steel was mostly a mixture of lath martensite (ML) and granular bainite (Bg) with a fine but nonuniform grain structure. The cause of brittleness in the ICHAZ was related to production of the M–A constituent in the local region and carbide precipitation. By controlling the welding heat input carbide precipitation and the formation of the M–A constituent can be avoided or decreased.
Volume 43, 2020
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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