232. Stainless steel contains
A.Chromium, iron and nickel
B.Chromium and nickel
C.Iron and carbon
D.Chromium, nickel, iron and carbon
233. Billets are
A.Obtained from solidification of molten metal into moulds
B.Obtained by passing hot ingots through the rolling mills and are of size 150 mm x 150 mm to 350 mm x 350 mm
C.Obtained by further rolling and are of size 50 mm x 50 mm to 125 mm x 125 mm
D.Scraps from unused blooms
234. Oxygen lance in open hearth furnace is used to
A.Measure O2 content
B.Remove O2
C.Introduce O2 in furnace
D.Maintain O2 at a constant value
235. As the impurities are oxidised, the melting point of iron
A.Increases
B.Decreases
C.Remains same
D.Depends on the type of furnace used
236. Following etching solution is used for low-carbon steel and welds
A.Nital - 2% HNO3 in ethyl alcohol
B.Picral - 5% picric acid and ethyl alcohol
C.1% hydrofluoric acid in water
D.50% NH4OH and 50% water
237. In making high silicon content steel, scrap can be used
A.To form slag
B.As catalyst
C.To control grade
D.As coolant
238. In making high silicon content steel, scrap can be used
A.To form slag
B.As catalyst
C.To control grade
D.As coolant
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