GB/T 13447-2008Steel blank for seamless gas cylinder (English PDF)

3.1 Dimensions

3.1.1 The cross-sectional dimensions and tolerances

3.1.1.1 seamless cylinders billets with cross-sectional dimensions and tolerances shall comply with the provisions in Table 1.

3.1.1.2 According to the requirements, the agreement by both sides, can supply other sizes of billets, tolerance and its side diagonal length difference should Specified in the contract.

3.1.2 Length and tolerance

3.1.2.1 billet usual length of 4m ~ 12m.

3.1.2.2 and agreement by both sides in the contract, the length of 2m ~ 4m short ruler blank to allow delivery.

3.1.2.3 billet set, double length agreement by both parties and specified in the contract, will double length tolerance is 0mm ~ 50mm.

3.2 Shape

3.2.1 billet may not have a significant twist

3.2.2 Curvature

Curvature per meter slab should be less than 15mm, the total curvature should not exceed 1.5% of the total length.

3.2.3 The broadening of slab steel billet ends may not exceed 10% of the nominal size of the slab cut slope should be less than 8mm.

3.3 Wt

Billet according to the actual weight of the delivery. Agreement by both sides, in accordance with theoretical weight delivery, the theory billet unit weight is determined by supply and demand sides.

4.1 Designation and chemical composition

4.1.1 Steel grade and chemical composition (melting analysis) should meet the requirements of Table 2. Finished tolerances shall comply with the provisions of GB/T 222's.

4.1.2 Residual elements V, Ti, Nb, B, Zr, and the content should not exceed 0.15%. As the supplier to ensure, may be tested

.

4.1.3 agreement by both sides, can also provide other grades of steel.

Note 1. According to the requirements, grade 30CrMo, 34CrMo sulfur content can be reduced to 0.010%, P + S can be reduced to 0.025%.

Note 2. Grade 34CrMo equivalent EN10083.1 of 34CrMo4.

<=0.30 - <=0.20 37Mn 0.34 ~

<=0.20 34CrMo 0.30 ~

<=0.030 <=0.030 - - <=0.30 - <=0.20 30CrMo 0.26 ~

4.2 Manufacturing Methods

Seamless steel gas cylinders after use oxygen converter or electric furnace smelting and refining, vacuum degassing manufacturing methods.

4.3 Delivery status

In the state of delivery hot rolled seamless cylinders billets.

4.4 Mechanical Properties

4.4.1 mechanical properties of the sample with heat-treated blank prepared specimen can be measured with reference to the provisions of Table 3.

4.4.2 Table 3 for the impact energy of the arithmetic mean of three samples, three samples are allowed to have a value smaller than a predetermined value, but not less than Regulation 70% of the set value.

4.5 Low magnification

4.5.1 Transverse acid leaching slab on low magnification specimen there is no visible residual shrinkage, white point, delamination, cracks, bubbles, foreign bodies and metal clip miscellaneous. Depth skin and subcutaneous bubble inclusions shall not exceed 2mm.

4.5.2 acid leaching low magnification level shall comply with the requirements of Table 4.

4.5.3 continuous casting technology, the size of not less than 250mm × 250mm billet, center porosity level consultations by both parties determine.

4.6 Non-metallic inclusions

Non-metallic inclusions should be GB/T 10561 inspection method A, the test results should meet the requirements of Table 5.

4.7 Surface quality

4.7.1 billet end face there is no visible shrinkage, inclusions and stratification.

4.7.2 billet surface may not have scarring, inclusions, folding, crack and ears.

4.7.3 billet surface allows the depth of not more than 1mm hairline and no deeper than the side length of the allowable negative deviation of individual scratches, indentation, concave Pit and pitting exist. Nicks and depression due to the roll joints caused by the projection shall not exceed 2mm.

4.7.4 slab surface defects should be cleaned. Cleanup should be carried out along the longitudinal direction of the billet, no clean up at the edges and corners should be smooth, clear width of not less than Five times the depth cleanup, clean-depth on the same cross-section (from the date of actual size) must not exceed 7.5% of nominal size.

6.1 Inspection and acceptance

Billet inspection and acceptance by the supplier is responsible for the technical quality supervision departments, the need for acceptance is entitled in accordance with this standard.

6.2 Batch rules

Billet should be granted acceptance, each batch from the same heat, the same brand, same size billet components.

6.3 Reinspection and decision rules

6.3.1 Impact test

At first test failed, should be on the same furnace number three and then take another branch billet retest samples, sample test results before and after the six arithmetic The average of not less than the predetermined value, less than the predetermined value of not more than two individual specimens, samples of which can not be less than 70% of the more than one.

6.3.2 Low magnification, non-metallic inclusions, tensile test

6.3.2.1 White point allowed a retest

6.3.2.2 For the molding process to produce billets, at first failed test, the billet early test failed to pick out, the equivalent of the ingot in any batch Head "A" section of the billet end double take samples of the defective item retest. Results retest if a specimen failed, the batch All "A" section of the slab can not be accepted. At this early test samples taken from the "A" section of the billet and the other end and then cut the sample tested. If the test result There is still a failure, then the batch shall not be accepted.

6.3.2.3 For continuous casting billet production, at first failed test, the billet early test failed to pick out, should retest samples were collected from two Since the beginning of the test samples of the same cast and another stream flow casting rolling billets, two retest samples retest results are satisfactory, the whole batch is qualified. Two samples were re-inspection Standard, should again test sample, in which the same stream twice cast the test results fail, the casting flow failure; if a test failed, then Where the failure to respond casting billet casting stream and other streams continue billet rolling on sampling and testing, until qualified so far.

6.3.3 Other

Other inspection reinspection implementation of the project according to the provisions of GB/T 2101's.

7.1 Marks

In the end marked billet steel grade, heat number, the molding process to produce billet, billet end face of the ingot head must all Clearly marked "A" word, the end face of the ingot billet tail marked "Z" word. For the production of billet continuous casting process should be marked at one end of the stream or No. Sequence number.

7.2 Quality Certificate

Content quality certificate shall comply with the relevant provisions of GB/T 2101's.