A Mössbauer Spectral Study of the Hull Steel and Rusticles Recovered from the Titanic

Study Objective:

• The study aims to characterize the hull steel and rusticles from the Titanic using Mössbauer spectroscopy.

Titanic’s Voyage and Sinking:

• The Titanic began its maiden voyage on April 10, 1912, and sank on April 15, 1912, after hitting an iceberg.
• The wreck was discovered in 1985 at a depth of 3,840 meters.

Sample Collection:

• Samples of the hull steel and rusticles were collected from the wreck site.
• The hull steel samples were taken from the debris field between the bow and stern sections.

Hull Steel Analysis:

• The hull steel was found to have low carbon content (0.21 wt% carbon).
• Mössbauer spectra showed the steel to be similar to α-iron with a weak magnetic anisotropy.
• The steel exhibited banding due to rolling, with average grain sizes of 60 µm (longitudinal) and 42 µm (transverse).

Rusticles Analysis:

• Rusticles are bioconcretious structures formed by bacteria and fungi.
• The rusticles contained mainly goethite (α-FeOOH) particles, with an average size of 20 ± 5 nm.
• Small amounts of green rust and lepidocrocite were also present.
• The rusticles showed superparamagnetic relaxation, with a blocking temperature around 300 K.

Experimental Techniques:

• Standard metallographic techniques were used to prepare the steel samples.
• Conversion electron Mössbauer spectroscopy (CEMS) and transmission Mössbauer spectroscopy were employed for analysis.
• X-ray powder diffraction was used to identify the mineral components of the rusticles.

Findings and Conclusions:

• The hull steel’s properties were consistent with low carbon steel, showing no preferred crystallographic orientation.
• The rusticles’ composition and formation process were similar to known corrosion processes, unaffected by the deep ocean’s extreme conditions.
• The study provided insights into the degradation of the Titanic’s materials over time.