SNR490B, Bar for building structure JIS G 3138

SNR490B, Bar for building structure JIS G 3138
STEELMAX Steel Story

SNR490B, JIS Bar for Building Structure
STEELMAX Steel Story.

SNR490B は, 建築構造用丸棒に対する規格です
JIS G3138により、SNR490B, SNR400B, SNR400A、三つのグレードの一つです。

KS規格のSNR355Bと対応可能な規格ですが、
KS規格の降伏強度は355MPa Minimumのことで、JIS規格のSNR490Bより高いです。

建築構造用鋼材は耐震用鋼材でSymbol記号が
丸棒はSNR、プレートはSN,H形鋼はSHN,パイプはSNTで、
製品によって使用される記号が分かれます。

熱間圧延丸棒でD6からD100 mmまでのみ規定されてます。
SNB490B, 鋼材の場合、Charpy V-Notch、
0℃/27 joule minimumまで衝撃試験がある鋼材です。

※ Steel for structure (構造用鋼)
Steel products manufactured for building, bridges, ships, vehicles,
and other structure uses, which require high strength,
if required weldability as well

※ Yield Strength (降伏强度)
Value of load strength which a specified permanent elongation
occurs in tensile test, expressed by dividing the load by original
sectional area of parallel portion.
the yield strength is used instead of yield point.

※ Charpy V-Notch Impact Test (CVN)
Test to measure the absorbed energy, impact value, percentage
of brittle/ductile fracture, transition temperature, etc. with using
charpy impact testing machine in which test piece is supported by
two supports distant by 40 mm so that the notch meets the middle
between supports and is broken by striking with one blow of
pendulum to the face opposite the notch.

SNR490B, JIS G3138
Chemical composition (%)	Carbon (C)	0.18 (6≤d≤50
	Carbon (C)	0.20 (50＜d≤100)
	Silicon (Si)	0.55 max
	Manganese (Mn)	1.60 max
	Phosphorus (P)	0.030 max
	Sulfur (S)	0.030 max
Ceq (%, max)	d≤40	0.44
Ceq (%, max)	40＜d≤100	0.46
Pcm(%,max)		0.29
Proof strength (MPa, min)	6≤d＜12	325
	12≤d＜40	325~445
	40≤d≤100	295~415
Tensile strength (MPa, min)		490~610
Yield ratio (%, min)	6≤d＜12	–
Yield ratio (%, min)	12≤d≤100	80
Elongation (%, min)	6≤d≤25	20
Elongation (%, min)	25＜d≤100	21
CVN V-notch rolling direction		0℃/27 joule min