Effect of Alloying Elements
Effect of Alloying Elements (Cr, Mn, Ni) on the Soundness of Low Carbon Steel Castings
Low Carbon Steel (LCS)
Low-carbon steels contain up to 0.30% C. The largest category of this class of steel is flat-rolled products (sheet or strip), usually in the cold-rolled and annealed condition. The carbon content for these high-formability steels is very low, less than 0.10% C, with up to 0.4% Mn. Typical uses are in automobile body panels, tin plate, and wire products.
ASTM A217 Gr WC9 alloy Steel Composition
Element requirement |C |Mn |Si |P |S |Cr |Ni |Mo |Cu |W | |Minimum |0.130 |0.50 |0.00 |0.000 |0.000 |2.00 |0.00 |0.90 |0.00 |0.00 | |Maximum |0.180 |0.70 |0.60 |0.020 |0.020 |2.50 |0.50 |1.20 |0.30 |0.10 | |Applications of WC9 alloy
Used in • Casings of steam turbines, compressors, gas turbines. • Valves such as Globe Valve body and bonnet, Check Valve, Gate Valve. • Nozzles and chemical reactors. • Service temperatures up to about 570 °C.
Gate Valve Body Globe Valve Body
[pic]
Advantages: • Easily Weldable with similar weld metal. • Has higher resistance to Graphitization • High Creep resistance.
Limitations:
• Applicable for valves operating in the Temperature range of -20 to 1100 °F. • Has limited Corrosion resistance.
Carbon Equivalent (CE):
CE= C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15
• CE%0.05% causes Edge Surface defects in Low Carbon Steels annealed at 700°C. • Ni in the range of 0.5-0.8% lowers the transformation
Low Carbon Steel (LCS)
Low-carbon steels contain up to 0.30% C. The largest category of this class of steel is flat-rolled products (sheet or strip), usually in the cold-rolled and annealed condition. The carbon content for these high-formability steels is very low, less than 0.10% C, with up to 0.4% Mn. Typical uses are in automobile body panels, tin plate, and wire products.
ASTM A217 Gr WC9 alloy Steel Composition
Element requirement |C |Mn |Si |P |S |Cr |Ni |Mo |Cu |W | |Minimum |0.130 |0.50 |0.00 |0.000 |0.000 |2.00 |0.00 |0.90 |0.00 |0.00 | |Maximum |0.180 |0.70 |0.60 |0.020 |0.020 |2.50 |0.50 |1.20 |0.30 |0.10 | |Applications of WC9 alloy
Used in • Casings of steam turbines, compressors, gas turbines. • Valves such as Globe Valve body and bonnet, Check Valve, Gate Valve. • Nozzles and chemical reactors. • Service temperatures up to about 570 °C.
Gate Valve Body Globe Valve Body
[pic]
Advantages: • Easily Weldable with similar weld metal. • Has higher resistance to Graphitization • High Creep resistance.
Limitations:
• Applicable for valves operating in the Temperature range of -20 to 1100 °F. • Has limited Corrosion resistance.
Carbon Equivalent (CE):
CE= C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15
• CE%0.05% causes Edge Surface defects in Low Carbon Steels annealed at 700°C. • Ni in the range of 0.5-0.8% lowers the transformation