Anti Scale Compounds
Billets and ingots of metal are heated to high temperatures before further processes like hot rolling and hot forging. Scaling / oxidation and decarburisation occur on these billets and ingots during heating at high temperatures. Between 1.5% up to 5% of metal is lost due to scaling at high temperatures. Apart from material loss, scaling causes a number of issues like bad surface finish due to pit marks, reduced forging die life due to impact of hard scale on die during closed die forging, and mill skid situation in hot rolling. Scales fallen in furnace damage the hearth of the furnace and also the induction heater refractory and coils. Removal of scale from the plant is an unproductive, labour intensive work. Decarburisation occuring at high temperatures leaves the metal unfit for making critical components like rails, sensitive automotive parts like leaf-springs, etc., where decarburisation needs to be maintained as low as possible.After forming, the forged, cast or rolled components need to be heat-treated. During heat treatment, scaling causes problems of pit marks, poor surface finish, non-uniform heating and increased shot-blasting / acid pickling time due to heavy scaling.Use of ESPON anti-scale protective coatings manufactured by Steel Plant Specialities LLP ensures that scaling is prevented or substantially reduced. During hot rolling of expensive grades of steel such as stainless steel and alloy steels, a 50% reduction in total scale loss on ingots or billets is ensured. This leads to substantial savings due to increased yield. Decarburisation level can be consistently controlled in hot rolling and hot forging. During heat treatment, ESPON protective anti-scale coatings have often achieved zero scaling. However, results vary depending on various factors. Substantially reduced scaling during heat treatment leads to improved surface finish, reduced shot blasting time, reduced rejections and reduced quench cracking.