Preheating & Post Heating

When flamecutting heavy plate or alloy plate, preheating the plate prior to cutting will slow the rate with which the steel behind the cut edge can pull heat away from the cut – slow the speed of the quench – and so will reduce the hardening effect in the heat-affected zone. For best results, medium carbon plate like 1045, and alloy plate such as 4140 and 4340 should be uniformly heated to 400 degrees before cutting.

Oliver Steel uses three dedicated preheat tables to ensure that the alloy plate, medium carbon plate, and heavy plate we process for you is at the correct temperature before we flamecut. This care minimizes the hardening in the heat-affected zone, reduces the thermal stresses in the plate created by flamecutting (which reduces walking), and minimizes distortion.

Once cut, the hot pieces must be handled so they are protected from rapid cooling. In the case of medium carbon or alloy plate, flamecut parts should have further thermal treatment in order to eliminate the possibility of cracking from the stresses of flamecutting. Thermal treatment can also eliminate most of the changes to the metallurgical structure caused by burning.

At Oliver, our in-house furnaces are run every day, so your parts are annealed or stress relieved the day they are cut. Further care is given to critical parts and difficult alloys, which are returned to the preheat table while still hot, where they are kept until loaded in the furnace.