Speak to one of our team now +44 (0)1493 653535
Speak to one of our team now +44 (0)1493 653535
The Brief
ASAMS was engaged by Maintain Reliability to investigate the sudden fracture of a steel shaft within a high-pressure steam retort system at a multinational packaged‑foods facility, with similar shafts in service across multiple sites. Our end‑to‑end failure investigation, combining on‑site review with traceable laboratory NDT, chemical analysis, metallography, and mechanical testing confirmed the shaft as a 431‑type martensitic stainless steel and verified that the applied flame coating complied with the supplied procedure. We identified work‑hardening of the austenitic stainless‑steel collar, which scored the shaft surface and initiated opposing fatigue cracks that progressed to failure. ASAMS provided clear, practical recommendations to prevent recurrence and advised fleetwide checks of similar assets to reduce risk and downtime.
The Challenge
Client & Asset Overview
ASAMS were asked by Maintain reliability, a specialist reliability services provider to examine a failed steel shaft which was part of an oven system, on behalf of their client a large, multinational packaged foods business operating across multiple global markets.
The Challenge.
Similar shafts were in service at multiple sites, raising concern about repeat failures. The client needed a clear root cause and practical mitigations that could be applied across the asset population.
Scope of Work
ASAMS conducted a root cause failure investigation. Our metallurgists visited site to review the shaft, agree which sections and components to send to the laboratory, and issued a transparent quotation explaining each test and the insights it would provide. We coordinated a full scope of testing through our in house capabilities and trusted subcontractors where required.
Standards & References
• ISO 6892 – Tensile testing
• ISO 6507 – Vickers hardness testing
• Macro and micro
• PT (Dye penetrant testing) and MT (Magnetic particle testing)
• X ray fluorescence (XRF) and chemical analysis
Our Approach
ASAMS Approach & Methodology
We catalogued and photographed the evidence on receipt, maintaining full traceability of each component and sampling location. Non destructive methods were applied first to preserve critical surface features before sectioning. Representative samples were then prepared for metallography and mechanical testing, and results were consolidated into a clear, client focused report, with updates provided throughout.
The Result
Results & Findings
• The shaft material was confirmed as 431 type martensitic stainless steel.
• The flame coating process conformed to the supplied procedure; no coating defects were found in the areas examined.
• The mating austenitic stainless steel collar had work hardened in service, and scoring was observed on the shaft surface.
Interpretation & Root Cause
The work hardened collar produced surface scoring on the shaft, providing initiation sites for fatigue cracking on opposite sides. These cracks propagated under service loading until final fracture occurred.
Key Outcomes & Client Benefits
• Root cause confirmed with a clear evidence trail.
• Immediate recommendations issued to inspect similar shafts and address the collar-shaft interaction to prevent recurrence.
• Optional materials/process improvements available from ASAMS to enhance reliability across the fleet.
Services Provided by ASAMS
Failure analysis (end-to-end)
NDT
Chemical analysis
Macro and micro examination
Mechanical testing
Need certainty on a materials or failure issue?
ASAMS provides accredited metallurgical, mechanical, and corrosion testing to turn complex failures into clear, actionable decisions. Speak to a metallurgist today about your investigation or qualification requirements.
