HKIE Professional Assessment - Materials Discipline case studies
HKIE Professional Assessment - Materials Discipline · Put your knowledge to work in context.
The HKIE Professional Assessment in the Materials Discipline is the route by which an engineer training in materials engineering demonstrates to the Hong Kong Institution of Engineers that they can practise independently at professional level. It is aimed at graduates working in fields where material behaviour governs the outcome - structural and construction materials, metallic components and heat treatment, polymers, ceramics, composites and concrete, corrosion and surface protection, testing and quality assurance, failure investigation, and the standards and ethics that frame engineering decisions in Hong Kong. The HKIE Professional Assessment - Materials Discipline case studies are 5 cases and about 2,699 words.
1Through-Hardening Shortfall in a Large 4140 Forged Shaft
A 250 mm diameter, 2.8 m long shaft in AISI 4140 (42CrMo4) is forged, normalised, rough machined, austenitised at 850 °C for 3 h, oil quenched with moderate agitation, and tempered at 560 °C for 4 h. The drawing requires 45–50 HRC at 12.5 mm below the surface and a 0.2 % proof strength of at least 1,000 MPa.
647 words, about 3 min2Cracked Marine Jetty Deck: ASR or Chloride-Induced Corrosion?
A 28-year-old reinforced concrete jetty deck in Hong Kong is grade 40 with 150 mm nominal cover and sits in the splash zone. Inspection shows map cracking with white exudate on soffits and some D-shaped cracks parallel to the reinforcement.
550 words, about 3 min3Stray-Current Corrosion on a Buried Fire Main Near a DC Tramway
A 3 km DN600 cement-mortar-lined mild steel fire main runs parallel to a 1500 V DC tramway for 900 m at 8–15 m separation. The external coating is coal-tar enamel with known holidays from a previous survey.
526 words, about 3 min4Delayed Brittle Fracture of Galvanized Grade 10.9 Bolts
A steel roof truss uses M24 grade 10.9 bolts, hot-dip galvanized after acid pickling. Six weeks after erection at a coastal site, 12 of 240 bolts have fractured at the thread root.
449 words, about 2 min5Unapproved Concrete Mix Change and Substandard Rebar Certificates
On a 30-storey residential project, the approved concrete mix is grade C45 with 30 % PFA and a maximum w/c of 0.45. The ready-mix plant, facing a PFA shortage, proposes 25 % PFA and raises the w/c to 0.50 to maintain slump; the site engineer says cube results will probably still pass.
527 words, about 3 min