DETERMINING METHOD FOR QUANTITY OF SOLUTE ELEMENT IN AGEEHARDENING LEAD ALLOY

摘要

PURPOSE:To determine the quantity of a solute element speedily, simply and with excellent precision by a method wherein the melted lead is injected into a metal mold of a prescribed temperature, then a cycle of rapid cooling, heating and rapid cooling under a fixed condition is applied thereto and later the maximum yield load in bending is measured. CONSTITUTION:In a metal mold heated up to about the temperature of a room, preferably, the temperature of 0-50 deg.C so as not to influence on the speed of cooling and congelation of the melted lead is injected the melted lead heated, preferably, up to the temperature of 350-450 deg.C and congealed, and it is cooled down to the temperature of the room within 10min. Next, one cycle of continuous cooling, heating and cooling is applied to an alloy piece thus prepared in such a manner that it is made to contact with a hot place heated up to 120-130 deg.C for 5-10min and then is cooled down to the temperature of the room within 10min, the solute element contained in the lead alloy is educed so that the lead alloy piece bears the maximum yield load in bending, and the quantity of the solute element is determined by the yield load in bending at that time. As the lead alloy, the alloy of Pb-Ca containing Ca of 0.12% or less is preferable.