Knowledge Base
Technical guide to delta ferrite in austenitic stainless steel welds. Covers WRC-1992 Schaeffler diagram, Ferrite Number (FN), 3–8 FN optimal range for hot cracking prevention, sigma phase risk, and composition control.
Complete guide to acicular ferrite in steel weld metal. Covers intragranular nucleation at oxide/sulfide inclusions, interlocking needle morphology, CVN toughness compared to other weld microstructures, and inclusion chemistry requirements.
Guide to Widmanstätten ferrite in steel. Covers formation mechanism at moderate undercooling, HAZ appearance in welds, crystallographic orientation relationship with austenite, and detrimental effect on Charpy impact toughness.
Technical guide to retained austenite in hardened steels. Covers formation mechanism, effect of carbon content on fraction retained, problems in bearings and tool steels, XRD measurement, and sub-zero cryogenic treatment.
Complete guide to bainite microstructure in steel. Covers upper bainite (350–550°C), lower bainite (250–350°C), formation mechanism, bainite vs tempered martensite toughness comparison, and industrial applications.
Complete guide to martensite in steel. Covers diffusionless FCC→BCT transformation, Koistinen-Marburger equation, carbon content vs hardness relationship, lath vs plate morphology, and why tempering is essential.
Complete guide to pearlite microstructure in steel. Covers eutectoid reaction at 727°C, lamellar interlamellar spacing vs temperature, hardness, applications in rails and high-strength wire, and fine vs coarse pearlite.
Complete guide to cementite (Fe₃C) in steel. Covers orthorhombic structure, 6.67%C composition, extreme hardness, role in pearlite and hypereutectoid steels, network cementite embrittlement, and spheroidise annealing.
Complete guide to austenite (γ-iron) in steel. Covers FCC structure, 2.14%C solubility, austenitising temperatures, retained austenite, austenite stability, and the central role of austenite in all steel heat treatments.
Complete guide to ferrite (α-iron) in steel. Covers BCC crystal structure, 0.022%C solubility limit, mechanical properties, proeutectoid ferrite, Hall-Petch strengthening, and role in structural steels.