Characteristics for grade 20

Published by 管理 at March 26, 2019

Tags

Grade :	20 ( 20 )
Substitute:	15, 25
Classification :	High quality structural carbon steel

Chemical composition in % for grade 20 ( 20 )

C	Si	Mn	Ni	S	P	Cr	Cu	As
0.17 – 0.24	0.17 – 0.37	0.35 – 0.65	max 0.3	max 0.04	max 0.035	max 0.25	max 0.3	max 0.08

Temperature of critical points for grade 20 ( 20 ).

Ac₁ = 724 , Ac₃(Ac_m) = 845 , Ar₃(Arc_m) = 815 , Ar₁ = 682

Mechanical properties under Т=20^oС for grade 20 ( 20 )

Assortment	Dimension	Direct.	s_в	s_T	d₅	y	KCU	Heat treatment
–	mm	–	MPa	MPa	%	%	kJ / m²	–
Sheet heat-treatment, GOST 4041-71	4 – 14		340-490		28
Pipe hot strain, GOST 550-75			431	255	22	50	780
Pipe, GOST 8731-87			412	245	21
Pipe, GOST 10705-80			372	225	22
Rolled stock, GOST 1050-88	to 80		410	245	25	55		Normalizing
Rolled stock cold-worked , GOST 1050-88			490		7	40
Rolled stock annealed , GOST 1050-88			390		21	50
Band annealed , GOST 2284-79			310-540		18
Band cold-worked , GOST 2284-79			490-830