1. brand representation method

The grades of steel are composed of three parts: the first letter of the Chinese phonetic alphabet, the minimum yield strength specified, and the first letter of the Chinese phonetic alphabet of nuclear power. For example, Q420HD. Among them:

Q - the first letter of the Chinese phonetic alphabet: "Qu":

420 - the specified minimum yield strength value, unit MPa:

HD - the first letter of the Chinese phonetic alphabet in "nuclear power".

When the thickness of the steel plate is required, the symbol of the performance level, which represents the thickness direction (Z direction), is added after the above-mentioned brand number, for example, Q420HDZ25..

2. order information

At the time of order, the buyer shall provide the following information.

A) this standard brand;

B) the brand name;

C) specifications;

D) size and shape precision requirements;

E) weight;

F) delivery state;

G) special requirements.

3. mark example

GB 30814-2014 delivery is Q420HD, thickness 50mm, width 3500mm, and length 8000mm, marked as: GB30814-2014 Q420HD 50*3500*8000.

4. size, shape, weight and allowable deviation

The allowable deviation of the thickness of the steel plate shall conform to the provisions of the deviation of class C or class B in GB/T709-2006, and the other forms, dimensions, weights and allowable deviations should comply with the provisions of GB/T 709-2006.

5. smelting method

The steel is smelted by the converter or the electric furnace and is refined outside the furnace.

6. delivery state

The steel plate shall be delivered in a state of hot rolling, hot rolling and tempering, normalizing, normalizing and tempering, quenching and tempering (only Q420HD).

7. packing

The packing of the steel plate shall be in accordance with the provisions of GB/T 247.

8. sign

The plates should be clearly marked out the following contents: the identification symbol of the standard grade, number, number, specification, furnace steel (material number or batch number), the name of the factory, factory.

9. quality certificate

The steel sheet for each shipment shall be attached with a certificate of quality that proves that the plate is in conformity with the standard and the order contract. The certificate of quality shall comply with the provisions of GB/T 247.

10. correlation standard grade comparison table

This standard is compared to the standard ASME and ASTM standard used, as shown in table A 1

Table A1

Standard number

GB30814 Q205HD Q230HD Q250HD Q275HD Q345HD1 Q345HD2 Q420HD

ASTM SA-285/SA-285M-2012 Gr.C

ASME SA-283/SA-283M-2012 Gr.D

ASTM A36/A36M-2008 A36

ASME SA-516/SA 516M-2010 Gr70

ASTM A572/A572M.2012 Gr.50T2

ASTM A5288/A588M-2010 Gr.B

The characteristics of the steel for nuclear power are mainly included in the following aspects:

1. Nuclear power steel has a wide range of varieties. The steel covers carbon steel, alloy steel, stainless steel and nickel base material and so on, and it has more strict requirements. Because nuclear island equipment steel works in high temperature and high pressure environment for a long time, it requires suitable strength, high toughness and low brittleness transition temperature (NDT).

2. It is difficult to produce nuclear power steel, which is close to the limit level of advanced rolling mill at home and abroad. The main sheet is heavy sheet, large size, ultra wide, super thick, super heavy. If the CPR1000 steam generator tube is used for steel 18MND5, only one sheet of steel is close to about 40t.

3. Strict chemical composition requirements. Conventional island equipment steel generally requires P and S content below 0.015%, while nuclear island equipment steel requires that P and S content is less than 0.010%, 0.0005%.

4, strict and complicated mechanical properties. The sampling test significantly increased the number of simulated post weld heat treatment in the condition of delivery, need (SPWHT) after high temperature, room temperature and low temperature and different position of vertical and horizontal test, such as 16MND5 steel plate with a plate regulator, the most requested inspection required more than 50 impact test sample.

5, at work temperature, it has good structure stability, solderability, cold and hot processing nuclear fatigue resistance. Under reactor irradiation condition, it should have good sensitivity to radiation embrittlement.

6. It has strict nondestructive testing requirements. Most of the nuclear power equipment steel needs 100% ultrasonic inspection. The surface of the steel plate needs magnetic particle inspection, and it requires higher qualification for the flaw detection operator.

7, considering the long-term neutron radiation effect, the more the alloy elements are, the weaker the whole neutron radiation ability is. Generally, the alloy elements with strong radiation resistance are widely used. At present, Mn-Ni-Mo series low alloy and high strength steels are widely recognized in the world.

8. Nuclear power steel is divided into two major areas: carbon steel and alloy steel. The most typical international nuclear power plants are A508-3, A533 (B, D), BHW35 in Germany, 16MND5 in France, SFVV3 in Japan and so on. (purple flame)

Contact phone: Li Lu 15294606696 /0371-53376125 QQ:2263689735