What is the difference between 1.4028 stainless steel and 1.4021?

1.4028 420B stainless steel is a chromium martensitic steel. This steel contains an average of 13% chromium and no nickel. 1.4021 steel (also known as ASTM 420 and SS2303) is a martensitic stainless steel with excellent corrosion resistance.

1.4028 vs 1.4021 stainless steel characteristics
Low corrosion resistance
Low embodied energy
Easier to harden than 1.4021
Ferromagnetic
High carbon content: Due to the higher carbon content in the chemical composition, this stainless steel type has higher strength and is therefore easier to harden.
Corrosion resistance: Despite the poor corrosion resistance of the steel, at room temperature, 1.4028 420B stainless steel performs well in contact with certain carbonates, acetates and hydroxides.

1.4028 vs 1.4021 stainless steel Chemical composition
Chemical composition of 1.4028 stainless steel:
Carbon (C): 0.26% to 0.35%
Manganese (Mn): ≤1.50%
Silicon (Si): max. 1.00%
Chromium (Cr): 12.0% to 14.0%
Phosphorus (P): max. 0.040%
Sulfur (S): ≤0.030%

1.4028 vs 1.4021 stainless steel Processing and heat treatment
Hot forming temperature: 1100 to 800°C
Annealing temperature: 745 to 825°C
Quenching temperature: 950 to 1050°C
Tempering temperature: 625 to 675°C
Cooling method: slow cooling, air cooling, oil cooling or air cooling

Application areas of 1.4028 420B stainless steel
Dripping
Shaft seals
Piston connecting rods
Mining tools
Knives and blades