The steel 316LN for test (/% : 0.015C

0. 65Si

0. 90Mn

17.3Cr

12.8Ni

2. 6Mo

0. 018 ~ 0. 200N) is melted by a 50 kg vacuum induction furnace

adding chromium nitride in atmosphere after vacuum refining. The ingot is forged to Φ20 mm bar and hot-rolled to 4 mm sheet

then solid-solution-treated respectively at 1 100 for 30 min and 10 min

water quenching. Research results show that with increasing every 0. 010%N in stainless steel 316LN

the steel tensile strength and yield strength increase respectively by 9 MPa and 7 MPa

but the steel elongation decreases by 0. 55%

while the nitrogen content in steel on steel reduction of area has no influence

it keeps to about 72. 5% ; the nitrogen strongly improves the pitting corrosion resistance of stainless steel 316LN

with increasing every 0. 010% N

the pitting breakdown potential increases by 7 mV ； and appropriate adding nitrogen in steel (0. 079% N) is available to improve intergranular corrosion resistance of stainless steel 316LN

but excessive nitrogen content (more than 0. 120% N) is harmful to intergranular corrosion resistance of steel.