metals 3 Flashcards
(16 cards)
what the 2 main ways steel and iron can erode?
mile scale and rust
what causes mile scale?
manufacturing errors in steel and iron
how does mile scale erode metal?
creates a layer of the surface and makes the metal porous and brittle
what rust produced from?
oxidation (water + oxygen)
what are the 2 problems caused by rust?
decay of materials and expansion of material
what factor could cause rust?
environment, poor material choice and poor design
what are 4 ways of avoiding rust?
Non metallic coating (paint) Metallic coating (molten metal) Alloying (other material) Designing (bigger structure)
what is glass flake epoxy paint?
paint that does rust for 25 years
discovered in 2011
what are the methods of connecting steel?
riveling, bolting and welding
what is riveling?
rod heated and hammered through parent materials and “mushroom” at the end
what are the two types of bolts?
non preloaded bolts- parent materials able to move preloaded bolts (high strength friction grip)- (tight) parent materials do not move
what do the numbers represent for a non preloaded bolts of grade 4.6
4 means that the maximum tense strength in 400
6 means that the stiffness is 0.6 x 400
what is welding?
metal joined together with melted metal (like soldering)
what are the different types of weld?
fillet, partial butt weld and full butt weld
explain weld failure
the weld material shrinks when it cools which causes to be in tension and the parent in compression
what are the different weld inspections?
visual inspection dye penetrant inspection magnetic particle inspection ultrasonic flaw inspection radiography
