Linear expansion coefficient

differential scanning calorimetric (DSC) and heat capacity at constant pressure (Cp) curves

and high temperature mechanical properties of austenite stainless steel 304 (/%: 0. 040C

0. 45Si

1. 18Mn

0. 030P

0. 003 S

17. 24 Cr

8. 11 Ni) 40 mm x 1 500 mm hot-rolled plate are tested and analyzed by using Gleeble-1500D thermal simulation testing machine

DIL402C thermal dilatometer and STA449F3 comprehensive thermal analyzer. Results show that 1-est brittleness zone of steel 304 is 1 300 T to melting point

3-rd brittleness zone is 950 ~ 1 050 °C

the reduction of area at 1 050 ~ 1 250 °C is ≥60%

it has better hot ductility; the linear expansion and contraction coefficient of steel are respectiv

ely 20. 97 x 10

-6

〜21. 56 x 10

-6

and 21. 25 x 10

-6

~ 21. 84 x 10

-6

so it belongs to crack sensitive steel grade; during heating process from 1 000 °C to 1 400 °C the fluctuation of Cp curve is larger

it indicates there is crystallographic transformation to easily form defects in steel ； during cooling of steel 304 from 1 450 °C to 1 200 °C the curve of DSC is unsmooth

it indicates there is phase transformation in steel easily to produce cracks in steel.