GATE MT case studies

GATE MT · Put your knowledge to work in context.

GATE 2025 (Graduate Aptitude Test in Engineering) is a national-level computer-based examination organised by IIT Roorkee on behalf of the National Coordination Board, Department of Higher Education, Ministry of Education, Government of India. It is conducted jointly by IISc Bengaluru and seven IITs, and it assesses comprehensive understanding of undergraduate-level subjects in Engineering, Technology, Architecture, Science, Commerce, Arts and Humanities. The GATE MT case studies are 5 cases and about 4,754 words.

Blast-furnace instability after a coke lot change: peripheral channelling or hanging?

A 2,500 m³ blast furnace producing 5,200 t/day runs at a coke rate of 340 kg/tHM with 160 kg/tHM pulverised coal injection. Thirty hours after a new coke lot is charged, the furnace becomes unstable.

906 words, about 5 min 2

Electric-arc furnace dephosphorisation with high-phosphorus DRI: is the target achievable?

An electric arc furnace taps 120 t of steel from a charge of 84 t high-phosphorus DRI (0.12% P, 3.5% SiO2) and 36 t low-phosphorus scrap (0.03% P). The customer requires 0.020% P at tap for sour service.

903 words, about 5 min 3

Longitudinal cracks in peritectic slabs: superheat, mould flux or taper?

A slab caster with a 230 mm × 1,500 mm mould is casting a 0.13% C, 1.10% Mn steel at 1.25 m/min with 38 K superheat. The mould flux in use has basicity 1.35, crystallisation temperature 1,180 °C and viscosity 0.12 Pa·s at 1,300 °C.

962 words, about 5 min 4

A 4140 shaft missing core hardness: hardenability, quench severity or tempering?

A Ø60 mm × 600 mm shaft in AISI 4140 (0.40 C, 0.90 Mn, 0.95 Cr, 0.20 Mo) is austenitised at 850 °C, quenched in agitated oil of Grossmann severity about 0.4, and tempered at 450 °C for 2 h. The drawing specifies 45 HRC minimum at the quarter point and 48 HRC minimum at the surface.

932 words, about 5 min 5

Hydrogen-assisted HAZ cracking in a restrained HSLA node: which factor dominates?

A 25 mm thick HSLA plate (0.10 C, 1.40 Mn, 0.30 Si, 0.20 Cr, 0.20 Ni, 0.10 Mo, balance Fe) is welded into a highly restrained box node by shielded metal arc welding with 3.2 mm E7018 electrodes taken from an unheated site store; the packet was opened three days earlier. Ambient temperature is 3 °C, there is no preheat, interpass is 60 °C and heat input is 1.1 kJ/mm.

1,051 words, about 5 min