151. A steel containing 12 to 14% chromium and 0.12 to 0.35% carbon is called martensitic stainless steel. September 13, 2025 by Admin TRUE FALSE ✅ The correct answer is option A.
152. German silver contains September 13, 2025 by Admin 70% copper and 30% zinc 60% copper and 40% zinc 59% copper, 40% zinc and 1% tin 60.45% copper, 35.2% z ✅ The correct answer is option D.
153. Muntz metal (Yellow brass) contains September 13, 2025 by Admin 70% copper and 30% zinc 60% copper and 40% zinc 59% copper, 40% zinc and 1% tin 60.45% copper, 35.2% z ✅ The correct answer is option B.
154. Quenching is not necessary when hardening is done by September 13, 2025 by Admin case hardening flame hardening nitriding any one of these ✅ The correct answer is option C.
155. The addition of which of the following improves machining of copper? September 13, 2025 by Admin Sulphur Vanadium Tin Zinc ✅ The correct answer is option A.
156. The addition of manganese to aluminium improves corrosion resistance. September 13, 2025 by Admin Correct Incorrect ✅ The correct answer is option A.
157. 18-4-1 high speed steel contains September 13, 2025 by Admin vanadium 4%, chromium 18% and tungsten 1% vanadium 1%, chromium 4% and tungsten 18% vanadium 18%, chromium 1% and tungsten 4% none of the above ✅ The correct answer is option B.
158. The compressive strength of cast iron is __________ that of its tensile strength. September 13, 2025 by Admin equal to less than more than ✅ The correct answer is option C.
159. The red flame during the operation of a bessemer converter indicates that the September 13, 2025 by Admin air is burning out silicon and manganese silicon and manganese has burned out and carbon has started oxidising converter must be tilted to remove the contents of the converter red flame does not occ ✅ The correct answer is option D.
160. A steel alloy containing 36% nickel is called September 13, 2025 by Admin stainless steel high speed steel invar heat resisting steel ✅ The correct answer is option C.