Galvanizability of Advanced High-Strength Steels 1180TRIP and 1180CP

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 40; no. 8; pp. 1903 - 1910
• Main Authors: Kim, M.S., Kwak, J.H., Kim, J.S., Liu, Y.H., Gao, N., Tang, N.-Y.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2009; Springer; Springer Nature B.V
• Subjects: Annealing; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Exact sciences and technology; Fourier transforms; Ion beams; Materials Science; Mechanical properties; Metallic Materials; Metals. Metallurgy; Meteorology; Nanotechnology; Steel; Structural Materials; Substrates; Surfaces and Interfaces; Tensile strength; Thin Films; Bare Spot; Coating Quality; 1180TRIP Steel; Scanning Transmission Electron Microscope; Annealing Furnace; Strength; High strength steel
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-009-9880-7

In general, Si-bearing advanced high-strength steels (AHSS) possess excellent mechanical properties but poor galvanizability. The galvanizability of a transformation-induced plasticity (TRIP) steel 1180TRIP containing 2.2 pct Mn and 1.7 pct Si and a complex phase steel 1180CP containing 2.7 pct Mn and 0.2 pct Si was extensively studied using a galvanizing simulator. The steel coupons were annealed at fixed dew points in the simulator. The surface features of the as-annealed steel coupons, together with galvanized and galvannealed coatings, were carefully examined using a variety of advanced analysis techniques. It was found that various oxides formed on the surface of these steels, depending on the steel composition and on the dew point control. Coating quality was good at 0 °C dew point but deteriorated as the dew point decreased to −35 °C and −65 °C. Based on the findings, guidance was provided for improving galvanizability by adjusting the Mn:Si ratio in steel compositions according to the dew point.