12.07.2015 Views

Alloying Elements in Steel - Macsteel

Alloying Elements in Steel - Macsteel

Alloying Elements in Steel - Macsteel

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

MACSTEEL - SPECIAL STEELS CATALOGUELea Road Tel: (011) 897-5000Dunswart Fax: (011) 918-1125P O Box 6130, Dunswart 1508 Email: mac.dun@mactrad<strong>in</strong>g.co.zaSouth AfricaWeb: www.macsteel.co.zaMo. MolybdenumWhile Molybdenum improves the tensile strength and <strong>in</strong>creases the heatresistance and weldability of steel, the forgeability of steel with highmolybdenum, content decreases. When used <strong>in</strong> comb<strong>in</strong>ation with Chromiumand Nickel , Molybdenum may produce high yield po<strong>in</strong>ts and tensile strengthvalues.Ni. NickelBy add<strong>in</strong>g Nickel to steel the notch toughness is <strong>in</strong>creased significantly andis therefore alloyed for <strong>in</strong>creas<strong>in</strong>g toughness <strong>in</strong> case-harden<strong>in</strong>g, heattreatableand subzero toughness steels. Nickel comb<strong>in</strong>ed with Chromiumensures good through harden<strong>in</strong>g. Chrome-Nickel steels are Sta<strong>in</strong>less, heatresistant and resistant to scal<strong>in</strong>g. Nickel does not impair the weld<strong>in</strong>gproperties of steel.P. PhosphorusPb. LeadPhosphorus is normally regarded as be<strong>in</strong>g detrimental to steel and everyendeavour is therefore made to keep Phosphorus content <strong>in</strong> high gradesteels to a maximum of 0.03 to 0.05%.Lead is added <strong>in</strong> free cutt<strong>in</strong>g steels <strong>in</strong> amounts of 0.20 - 0.50%. Because ofits f<strong>in</strong>e homogenous distribution, formation of shorter chips and clean facesof cut is achieved, thus improv<strong>in</strong>g mach<strong>in</strong>eability. The stated lead contentdoes not effect the mechanical properties of the steel.S SulphurSulphur produces the most pronounced segregation of all steelaccompany<strong>in</strong>g elements. It leads to red shortness or hot shortness. Sulphuris added to steels for automatic mach<strong>in</strong><strong>in</strong>g <strong>in</strong> quantities of up to 0.40%. Thisreduces the friction on the tool cutt<strong>in</strong>g edges by means of lubricat<strong>in</strong>g action.thereby <strong>in</strong>creas<strong>in</strong>g tool life. It also produces shorter chips dur<strong>in</strong>g mach<strong>in</strong><strong>in</strong>g.Sulphur also <strong>in</strong>creases susceptibility to weld<strong>in</strong>g cracks <strong>in</strong> steel.A division of <strong>Macsteel</strong> Service Centre SA (Pty) Ltd: Reg. No 2005/016292/07Page 2 of 3

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!