Celtic steel - an evaluation of depot finds

In the course of archaeological excavations on the Grundberg in Linz/Austri a, several depots containing a total of 45 steel objects were discovered. T hese depots had been set up around 100 before Christ (BC). 25 objects were used to take samples for metallographic and microanalytical investigations. In the exercise of his trade, the Celtic smith could resort to different st eel grades: non-alloyed, carbon alloyed, phosphorus alloyed. The technique applied was that of fire-forging single pieces of steel-which had previousl y been widened by hammering-to give flat bars showing a multi-layer structu re. For workpieces with special requirements with regard both to hardness and t o toughness, a number of carefully selected flat bars with differing conten ts of alloying metals were bonded by forge welding, which produced a compou nd material. Hardening by cold working as well as by torquing was already k nown to these Celtic craftsmen. To obtain tools with a hard edge and a toug h core, cementation was used.