HARDNESS FUNCTIONS TO PREDICT WELDABILITY OF LOW CARBON STEEL (Data to Computer Data Bank)

Abstract

The determination of the expectable hardness of a welded joint can be carried out in the knowledge of the cooling time from 850 °C to 500 °C with function HV-Δt8 / 5 characteristic of the given material. On the basis of the known hardness criterion it can be determined whether the technology causing the given cooling time can be used or not. Direct connection is tried to be found between hardness and cooling time starting from relations in literature and chemical composition of base metals. In general we can state these relations reflect the character of hardness change but are not reliable to calculate the actual hardness values. Relations relying on separate, definite measurement results ensure the reliable prediction of expectable hardness of heat affected zone at characteristic types of steel. Parameters at our disposal in the form of computer data bank, on the other hand, make the fast establishment of the necessary relations possible.