Cold Drawn 8620 8640 Rebar Steel Construction Iron Rods Stainless Steel Round Bar

• Customization: Available
• Type: Round
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel, Mold Steel
• Application: Tool Steel Bar
• Surface: Milled/Bright/Black
• Length: 1-10m
• Transport Package: Wooden
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7214100000
• Production Capacity: 5000 Ton/Year

Product Description

Introduction:  

AISI 8620 steel Manufacturer and Exporter,supplied with round,square,flat,block,and shaft etc.AISI 8620 is defined as low carbon alloy steel which has 0.5% Cr, 0.2% Mo and 0.5% Ni as strengthening alloy elements.It is generally supplied as annealed condition with hardness HB255max.AISI 8620 has good wear resistant with case hardness HRC 60-63  when carburized, hardened and tempered.Compared with grades 8615 and 8617, it shows good core strength and toughness properties with a typical tensile strength range of 700-1100 MPa,in small to medium sized sections.

1.Supply Form & Size & Tolerance

Supply Form	Size(mm)	Process	Tolerance
Round	Φ6-Φ100	Cold Drawn	Bright/Black	Best H11
	Φ16-Φ350	Hot Rolled	Black	-0/+1mm
			Peeled/ground	Best H11
	Φ90-Φ1000	Hot Forged	Black	-0/+5mm
			Rough Turned	-0/+3mm
Flat/Square/Block	Thickness :120-800	Hot Forged	Black	-0/+8mm
	Width:120-1500		Rough Machined	-0/+3mm

Remark:Tolerance can be customized as per requests
2.Chemical Composition

Standard	Grade	C	Si	Mn	P	S	Cr	Ni	Mo
ASTM A29	8620	0.18-0.23	0.15-0.35	0.7-0.9	≤ 0.035	≤ 0.04	0.4-0.6	0.4-0.7	0.15-0.25
EN 10084	1.6523	0.17-0.23	≤ 0.04	0.65-0.95	≤ 0.025	≤ 0.035	0.35-0.70	0.4-0.7	0.15-0.25
	20NiCrMo2-2
JIS G4103	SNCM220	0.17-0.23	0.15-0.35	0.6-0.9	≤ 0.03	≤ 0.03	0.4-0.65	0.4-0.7	0.15-0.3
BS 970	805M20	0.17-0.23	0.1-0.4	0.6-0.95	≤ 0.04	≤ 0.05	0.35-0.65	0.35-0.75	0.15-0.25
GB 3077	20CrNiMoA	0.17-0.23	0.17-0.37	0.6-0.95	≤ 0.035	≤ 0.035	0.4-0.7	0.35-0.75	0.2-0.3

3.Physical Property

Density g/cm3	7.85
Melting point Deg F	2600
Poisson's ratio	0.27-0.30
Machinability (AISI 1212 as 100% machinability)	65%
Thermal expansion (20 ºC)(ºC ¹)	12.2*10^-6
Specific heat capacity J/(kg*K)	477
Thermal conductivity W/(m*K)	46.6
Electric resistivity Ohm*m	2.34*10^-7

4. Mechanical Property
Typical Mechanical Properties For Core - Carburised and Oil Quenched at 840  °C

Section Size	11mm	30mm	63mm
Tensile Strength Mpa	980-1270	780-1080	690-930
Yield Strength Mpa	≥785	≥590	≥490
Elongation %	≥9	≥10	≥11
Charpy Impact J	≥41	≥41	≥41
Hardness HB	290-375	235-320	205-275
Hardness HRC	31-41	23-35	16-29

5.Hardenability Limits

Distance from quenched end mm	1.5	3	5	7	9	11	13	15	20	25	30	35	40
HRC Min	41	37	31	25	21	-	-	-	-	-	-	-	-
HRC Max	48	47	43	39	35	32	30	29	26	24	23	23	23

Hardness values under 20HRC  is not specified.
6.Forging
Forging temperature should be carried out between 925ºC-1230ºC,AISI 8620 has low carbon content  which is  less susceptible to cracking than medium or high carbon steels,so  it may be heated and cooled more rapidly.Soaking time at forging temperature should be as short as possible to avoid heavy scaling and excessive grain growth.The lower the forging-ending temperature ,the finer the grain size .Don't forge below minimum forging temperature 850°C.This alloy should be cooled in sand.
7.Normalizing
Normalizing is used to refine the structure of forgings that might have cooled non-uniformly after forged,and considered as a conditioning treatment before case hardening.Normalizing temperature for AISI 8620 steel should be carried out between 900ºC-925ºC. hold suitable time for the steel to be thoroughly heated to complete the ferrite to austenite transformation.Cool in still air.This treatment is considered as another method of improving machinability.
8.Annealing
Full annealing is recommended  for AISI 8620 before machining, AISI 8620  should be carried our at a nominal temperature of 820ºC-850ºC,hold suitable time for the steel to be thoroughly heated, then furnace cooling.
9.Case Hardening
Following core refining, Heat the temperature to 780^oC - 820^oC, hold suitable time for the steel to be thoroughly heated, and quench in oil.Temper as soon as possible after quenched.
10.Tempering
Tempering is usually carried out to relieve stresses from the hardening process,it will improve the toughness of both case and core, with only a little reduction in core strength and case hardness.Heat the AISI 8620 steel to 150^oC - 200^oC as required, hold enough time until temperature is uniform throughout the section, soak for 1 - 2 hours per 25 mm of section, and cool in still air.
11.Caburizing
Pack, salt or gas carburize at temperature  900^oC - 925^oC, holding enough  time to obtain the required case depth and carbon content, followed by a suitable hardening and tempering cycle to optimise case and core properties.
12.Applications
AISI 8620 is suited for applications which require a combination of toughness and wear resistance.It is commonly used in the engineering and automitive industries for toolholders and other such components.
Typical application:Arbors, pinions, bushes, camshafts, kingpins,ratchets, gears, splined shafts etc.