Certificates

WYJ032-2005                               20HR

1, applicable scope

The technology conditions apply to nuclear power project steel lining the secure with 20 HR steel plates.

2, the reference standard

GB/T222 steel chemical analyses of the sampling method and finished with the chemical composition allow deviation

GB/T223 iron and steel chemical analysis method

GB/T228 metal materials tensile testing at method

GB/T229 metal charpy impact test method

GB/T232 metal bending test method

GB/T247 steel plate and steel belt inspection, packaging, sign and quality certificate of general rules

GB/T709 hot-rolled steel plate and steel with size, shape, weight and allow deviation

GB6654 pressure vessel USES of the steel plate

3, size, shape, weight and allow deviation

3.1 the steel plate length, width, roughness deviation should be allowed to meet the provisions of GB/T709.

3.2 the thickness of the steel plate deviation should be allowed to meet the provisions of the GB6654.

3.3 plates shall be ordered to theoretical weight delivery, according to the provisions of the GB6654 added value to the thickness of the weight calculation theory.

4, technical requirements

4.1the melting analysis and finish product analysis comply with the provisions of the table 1.

Table 1  20HRchemical composition of the steel plate  ％

 

	C≤	Si ≤	Mn	P ≤	S ≤	TAl ≥	Cr ≤	Cu ≤	Mo≤	Nb≤	Ni ≤	Ti ≤	V ≤	N ≤
Melting analysis	0.20	0.40	0.80～1.40	0.025	0.015	0.020	0.30	0.30	0.08	0.02	0.05	0.03	0.02	0.014
Product analysis	0.22	0.45	0.75～1.50	0.030	0.020	0.015	0.35	0.35	0.11	0.03	0.35	0.04	0.03	0.014

note：1.Al/N≥2

2. Cr+Cu+Mo+Ni≤0.70

4.2 delivery status

Steel should be to state delivery normalized, normalized temperature is 890-940 ℃.

4.3 mechanical properties and process performance

4.3.1 ≥35 mm thickness of the steel plate doing the PWHT, sample PWHTstate mechanical performance and process performance should comply with the regulations of table 2.

Table 2  20HRSteel plate mechanics and process performance

 

Steel Thicknesst mm	tensile property			Impact property （transverve）		180°bending test
	ReH,MPa	Rm,MPa	A,%	Test temperature	Akv,J	b=35mm
≤16	≥265	410 ～ 530	≥ 24	-20℃	≥	d=1a
16＜t≤40	≥255
40＜t≤60	≥245
60＜t≤100	≥215
100＜t≤150	≥200	400～530

Note: three impact allows only a sample of the test results lower than average, but shall not be lower than the average of 70%.

4.3.2 sample simulation after welding heat treatment system are as follows:

Warming: from 300 ℃began to 70-80 ℃/ hour speed to heat up

Heat preservation temperature: 600 ℃±5 ℃

Holding time: six hours

Temperature: ≤80 ℃/ hour to cooling to 300 ℃, air cold (including t = 110 mm thick plate ≤55 ℃for cooling speed per hour.