Description

Advantages

Hot rolling usually adopts large ingots and large weight reduction rolling, which not only improves the production efficiency, but also creates conditions for increasing the rolling speed and realizing the continuous and automation of the rolling process. The advantages of hot rolled steel sheet include: increased ductility, wide application range, high productivity, and lower cost than cold rolled.

Properties of Hot Rolled Steel Sheets

Hot-rolled steel typically requires fewer steps than cold-rolled steel, and therefore costs less. But since the hot rolled steel sheet can be cooled at room temperature, it is not affected by the internal stress generated during quenching or work hardening. Hot rolled steel sheets can be identified by the following characteristics:

1. A scaly surface – cooling residue at extreme temperatures
2. Slightly rounded corners of sheets and bars due to shrinkage and less precise machining
3. Slight deformation – cooling may form a slightly trapezoidal shape rather than a perfect right angle.

Relative steel grade

S235 JR, S235 JRG2, S235 J0, S235 J2,
S275 JR, S275 J0, S275 J2,
S355 JR, S355 J0, S355 J2, S355 J2G3, S355 J2G4, S355 K2, S 355 K2G3, S355 K2G4 Q235, Q355

S355 J0：Structural grade S, minimum yield strength 355N/mm2, J0 grade confirms that the steel passes the longitudinal Charpy V-notch impact test at 0°C, 27J.

S355 J0+AR：Structural grade S, also with a yield strength of 355 N/mm2, but in rolled form.

S355 J0+N：Structural class S, also with a yield strength of 355N/mm2, but supplied in the normalized condition.

S355 is widely used in structural engineering and construction industry, and the workability of S355 J0 structural steel and marine steel plate is similar to that of low carbon steel, and it also has excellent weldability and good impact resistance.
Q235 steel plate has good plasticity, toughness, weldability and certain strength, and has good cold bending performance.
Q355 steel plate has good mechanical properties, welding properties, hot and cold processing properties and corrosion resistance, and can be used to manufacture welded structures with high loads such as ships, boilers, and bridges.

Sheet Specifications

thickness	width	length	standard	technology
1~200mm	1000~1500mm	1000~12000mm	EN 10025-2:2004	hot rolled

chemical composition

grade	Chemical composition not greater than Max.(%)
	C	Si	Mn	P	S
Q235A	0.22	0.35	1.4	0.045	0.05
Q235B	0.2	0.35	1.4	0.045	0.045
Q235C	0.17	0.35	1.4	0.04	0.04
Q235D	0.17	0.35	1.4	0.035	0.035
Q355A	0.2	0.5	1.7	0.035	0.035
Q355B	0.2	0.5	1.7	0.035	0.035
Q355C	0.2	0.5	1.7	0.03	0.03
Q355D	0.18	0.5	1.7	0.03	0.025
Q355E	0.18	0.5	1.7	0.025	0.02

grade	Chemical composition not greater than Max.(%)
	C			Si	Mn	P	S	N	Cu
	t≤16	16<t≤40	t>40
S275 JR	0.21	0.21	0.22	N/A	1.5	0.035	0.035	0.012	0.55
S275 J0	0.18	0.18	0.18	N/A	1.5	0.03	0.03	0.012	0.55
S275 J2	0.18	0.18	0.18	N/A	1.5	0.025	0.025	N/A	0.55
S355 JR	0.24	0.24	0.24	0.55	1.6	0.035	0.035	0.012	0.55
S355 J0	0.2	0.2	0.22	0.55	1.6	0.03	0.03	0.012	0.55
S355 J2	0.2	0.2	0.22	0.55	1.6	0.025	0.025	N/A	0.55
S450 J0	0.2	0.2	0.22	0.55	1.7	0.03	0.03	0.025	0.55

Mechanical behavior

grade	Yield strength not less than Min. (N/mm2)			tensile strength	Elongation not less than Min. (N/mm2)			Impact test
	t≤16	16<t≤40	40<t≤60	（N/mm2）	t≤40	40<t≤60	60<t≤100	Temperature (℃)	Energy Min. (J)
Q235A	235	225	215	375~500	26	25	24	N/A	N/A
Q235B	235	225	215	375~500	26	25	24	20	27
Q235C	235	225	215	375~500	26	25	24	0	27
Q235D	235	225	215	375~500	26	25	24	-20	27
Q355A	355	335	325	470~630	20	19	19	N/A	N/A
Q355B	355	335	325	470~630	20	19	19	20	34
Q355C	355	335	325	470~630	21	20	20	0	34
Q355D	355	335	325	470~630	21	20	20	-20	34
Q355E	355	335	325	470~630	21	20	20	-40	34

When thickness t=16

grade	Yield strength not less than Min. (N/mm2)			tensile strength	Elongation not less than Min. (N/mm2)			Impact test
	t≤16	16<t≤40	40<t≤60	（N/mm2）	t≤40	40<t≤60	60<t≤100	Temperature (℃)	Energy Min. (J)
Q235A	235	225	215	375~500	26	25	24	N/A	N/A
Q235B	235	225	215	375~500	26	25	24	20	27
Q235C	235	225	215	375~500	26	25	24	0	27
Q235D	235	225	215	375~500	26	25	24	-20	27
Q355A	355	335	325	470~630	20	19	19	N/A	N/A
Q355B	355	335	325	470~630	20	19	19	20	34
Q355C	355	335	325	470~630	21	20	20	0	34
Q355D	355	335	325	470~630	21	20	20	-20	34
Q355E	355	335	325	470~630	21	20	20	-40	34