Billet (forging raw material) pre-forging heating is an indispensable part in the whole forging process, which has a direct effect on improving forging productivity, guaranteeing the quality of forgings, saving energy consumption and reducing product cost.
I. Purpose and requirements of heating
(1) The purpose of heating
Improve metal plasticity, reduce metal deformation resistance, make it easy to shape, and obtain good post-forging structure and mechanics
(2) Heating requirements
① is heated to predetermined temperature at the fastest speed under the condition of the permissible temperature and internal stress of metallic materials.
degree, improve efficiency, save energy.
② minimize the absorption of harmful gases such as oxygen, hydrogen and nitrogen by heating metals, reducing oxidation, decarburization, or hydrogen embrittlement.
and other defects to improve the heating quality.
③ in the low-temperature heating stage, to prevent improper heating due to the metal cross-section of the outer layer and the heart produced too much temperature
, resulting in excessive thermal stress, and then superposition of other internal stresses, causing the material to rupture.
④ accurately implement given heating conditions such as heating temperature, speed, time and heat preservation to prevent
Overheating, burning and other defects.