ENAMEL FOR STEEL Russian patent published in 1994 - IPC

FIELD: metallurgy, protecting materials. SUBSTANCE: enamel for steel has the following components, wt.-%: silicon oxide (SiO₂) 33-35; copper oxide (CuO) 1.0-2.5; aluminium oxide (Al₂O₃) 3.0-4.5; sodium oxide (Na₂O) 25.8-26.5; boron oxide (B₂O₃) 20-21; ferric oxide (Fe₂O₃) 2.5-5.0; titanium oxide (TiO₂) 1-3; cobalt oxide (Co₂O₃) 0.25-0.5; phosphorus pentoxide (P₂O₅) 1.0-1.95; nickel oxide (NiO) 0.5-1.2; manganese oxide (MnO₂) 4-6, and tin oxide (SnO₂) 0.03-0.1. Properties of enamel coating: expansion strength is 85-100 MPa, compression strength is 0.8-1.2 MPa, bending strength is 150-190 MPa. Wear-resistance of coating is 565 h. After loading for strength under sign-variable conditions and after reversing regime for 565 h no visible cracks and splitting-off of coating surface are detected. Enamel is used in machine engineering. EFFECT: enhanced quality of enamel. 2 tbl