METALLURGY
During heat treatment, deformation and volume changes can be minimised by
slowly cooling in the martensitic range
using surface hardening when possible
using alloy steels least prone to such changes
Any of the above
Quenching cracks during heat treatment can be minimised:
by avoiding sharp projections and sudden transitions from thick to thin sections
articles should be free from stress before heat treatment
heat to minimum stable temperature for hardening
Any of the above
Which of the following furnace is used for steel only?
Cupola
Air furnace
Open hearth furnace
Indirect arc furnace
During heat treatment the formation of thick layer of scale on the surface of steel articles is mainly due to
excessive hardness
oxidation
reduction
coarse grain structure
During heat treatment quenching cracks occur due to
irregular martensitic transformation within the article
oxidising atmosphere within the fumace
heating at higher temperatures for longer durations
All of the above
{"name":"METALLURGY", "url":"https://www.quiz-maker.com/QUMGKIEY","txt":"During heat treatment, deformation and volume changes can be minimised by, Quenching cracks during heat treatment can be minimised:","img":"https://cdn.poll-maker.com/56-2220367/whatsapp-image-2020-06-18-at-12-18-01.jpeg?sz=1200"}