15F 
 15F 
 ● 15F Features: 15F steel strength, hardness, ductility and 10/10F steel similar to send its cutting or water in need of tough treatment normalized to an appropriate increase in hardness, ligaments, welding, good hardenability and hardenability are low. 

 ● 15F Use: 15F steel as a major discontinuity, the switch is simple, but the toughness is higher or better welding performance, the summary components, as well as carburized parts, machinery and tight soft firmware, do not die forging and heat treatment low-load parts, such as bolts, screws, flange and receptacle chemical machinery, steam boilers. 

 ● 15F Scope: for the manufacture of mechanical components used in carburizing parts, fastening parts and components at low load without heat treatment, such as screws, bolts, flanges and so on. 

 ● 15F mechanical properties: tensile strength σb (MPa): ≥ 355 (36) yield strength σs (MPa): ≥ 205 (21) Elongation δ5 (%): ≥ 29 Reduction of area ψ (%): ≥ 55 . 

 ● 15F steel chemical composition (chemical composition): 15F steel carbon (C) 0.12 ~ 0.19, chromium (Cr) ≤ 0.25, manganese (Mn) 0.25 ~ 0.50, Nickel (Ni) ≤ 0.25, silicon (Si) ≤ 0.07, P (P) ≤ 0.035, sulfur (S) ≤ 0.035, copper (Cu) ≤ 0.25.