GB/T 2524-2019Titanium sponge (English PDF)

3.1 Product classification

Titanium sponge products are divided into 7 grades (designations) based on chemical composition and Brinell hardness: MHT-95, MHT-100, MHT-110, MHT-125, MHT-140, MHT-160, MHT-200.

3.2 Chemical composition and Brinell hardness

3.2.1 The chemical composition and Brinell hardness of titanium sponge products shall comply with the requirements in Table 1.

3.4 Appearance quality

3.4.1 The product shall be light gray or silver gray sponge-like, with a clean surface and no visually visible inclusions. Some defective titanium sponge blocks are allowed.

3.4.2 Defective titanium sponge blocks refer to: oxidized titanium sponge blocks with obvious dark yellow or bright yellow color; oxidized and nitrogen-rich titanium sponge blocks with dark yellow or bright yellow traces; titanium sponge block with obvious chloride residues; titanium sponge block with high iron content and its associated elements; titanium sponge with dark gray surface with traces of moisture absorption, etc. Please refer to Appendix A for typical drawings of defective titanium sponge blocks.

If there are any special requirements, they shall be noted in the order form (or contract).

3.4.3 The weight of defective titanium sponge blocks in grade 0A, grade 0, grade 1 products are not allowed to exceed 0.05% of the total weight of the batch of products.

The weight of defective titanium sponge blocks in grade 2 and grade 3 products is not allowed to exceed 0.1% of the total weight of the batch of products.

5.1 Inspection and acceptance

5.1.1 Titanium sponge products shall be inspected by the supplier, to ensure that the product quality complies with the provisions of this standard and the order form (or contract); meanwhile a quality certificate shall be filled out.

5.1.2 The purchaser shall inspect the received products, in accordance with the provisions of this standard and the order form (or contract). If the test results of chemical composition and Brinell hardness are inconsistent with the provisions of this standard and the order form (or contract), the purchaser shall notice the supplier within 60 days from the date of receipt of the product. If the inspection results of particle size and appearance quality are inconsistent with the provisions of this standard and the order form (or contract), it shall notice the supplier, within six months from the date of receipt of the product, to be settled through negotiation between the supplier and the purchaser. If arbitration is required, arbitration sampling shall be carried out by both the supplier and the purchaser, in accordance with the provisions of B.4 among the products received by the purchaser.

5.2 Group-batching

Titanium sponge products shall be submitted for acceptance in batches. Each batch shall be composed of products of the same heat, grade (designation), particle size specifications. The batch size is 500 kg ~ 12000 kg.

6.3 Quality certificate

Each batch of products shall be accompanied by a quality certificate stating:

a) Supplier's name, address, telephone number, fax number;

b) Product name;

c) Batch number, particle size, grade or designation, weight, number of barrels;

d) Analysis results and stamp of the inspection department;

e) This standard number, order form (or contract) number;

f) Inspection date.

B.1 Scope

This Appendix specifies the sampling methods for titanium sponge products and the preparation methods of samples and test ingots for product's chemical composition analysis and hardness determination.

This Appendix is suitable for determining the mass of titanium sponge batch products.

B.2 Supplier sampling and test ingot preparation methods for titanium sponge products

B.2.1 Sampling method

B.2.1.1 In principle, sampling shall be carried out before the titanium sponge batch products are packaged. It is recommended to use an automatic sampling device for continuous sampling.

B.2.1.2 The specimen collection and preparation process shall make the sample taken represent the average composition of the batch product as much as possible.

B.2.1.3 The tooling used to collect specimens shall ensure that the specimens do not deteriorate or become contaminated.

B.2.1.4 Titanium sponge specimens are collected according to the following methods.

If there are special requirements, they can be resolved through negotiation between the supplier and the buyer:

a) Taking primary specimen After each batch of titanium sponge products is crushed, selected, fully mixed, take specimens of 30 g ~ 300 g from the continuously flowing titanium sponge, through an automatic sampling device, at certain time intervals. OR after batches of titanium sponge products are fully mixed, they are put it into a stainless steel rectangular vessel, spread to a uniform thickness, divided into equal parts according to its area; then use a stainless steel square shovel which has a capacity of not less than 1000 g, to take specimens of more than 300 g from each part. The total amount of specimen collected must be more than 0.5% of the batch size, at least no less than 20 kg.

b) Taking secondary specimen Spread the specimen collected in a) evenly on a stainless steel plate. Use the quartering method to divide the sample into no less than 4 kg, to obtain a secondary specimen. Then divide the secondary specimen into equal parts, to obtain 4 sets of specimens. Each set of specimen shall not be less than 0.9 kg. The secondary specimens represent the average composition of this batch of titanium sponge products and are used as supply specimens, for product chemical composition analysis and hardness test. One of them is the supplier's test specimen and the rest are retained specimen.

B.2.2 Preparation of specimens

B.2.2.1 Suppression of consumable electrodes

Put about 0.9 kg of the supplier's test specimen (the quantity is determined by the capacity of the stamper) into a clean stamper. Press it into a consumable electrode on a hydraulic press. The electrode forming pressure is 300 MPa ~ 500 MPa; the pressure holding time is 3 s ~ 5 s.

B.2.2.2 Vacuum casting titanium ingot

Put the pressed consumable electrode into a drying box to dry for 20 min ~ 40 min. The drying temperature is 90 °C ~ 105 °C. After drying, put it into a vacuum consumable furnace for casting. Before casting, check the system and perform pre-vacuuming. The absolute vacuum inside the furnace shall not be greater than 0.133 Pa; the air leakage rate shall not be greater than 0.667 Pa/min; the current intensity during casting is 900 A ~ 1100 A; the working voltage is 24 V ~ 45 V; the cooling water flow is 9 L/min ~ 12 L/min. The cooling time of titanium ingots in the furnace shall not be less than 20 minutes.

B.2.2.3 Preparation of test ingots and specimens

Clamp the titanium ingot taken out from the water-cooled copper crucible on the lathe.

Remove the shrinkage part of the ingot cap, at a speed of no more than 405 r/min. Turn off the 10 mm thick titanium layer on the lower part and the 5 mm thick side part of the ingot. The amount of feed of the lathe and amount of cutting should be such that oxidation does not occur on the surface of the test ingot. The sampling location is as shown in Figure B.1.

The preparation of various types of analytical specimens is as follows:

a) Preparation of oxygen, nitrogen, hydrogen analysis specimens Cut a titanium ring, which has an outer diameter of not less than 35 mm, a width of 5 mm ~ 7 mm, a thickness of 2 mm ~ 4 mm, a mass of not less than 15 g, from the middle of the ingot, for analysis of oxygen, nitrogen, hydrogen.

B.3.2 Preparation of test ingots

The pressing, casting, and preparation of each specimen of consumable electrodes shall be carried out in accordance with B.2.2.

B.4 Arbitration sampling and preparation method of test ingots for titanium sponge

B.4.1 Sampling

During arbitration sampling, both the supplier and the buyer shall be on site at the same time; sampling shall be carried out according to the following methods:

a) Randomly select 20% of the number of barrels from the disputed batch of products (not less than 3 barrels; OR all of them if the batch is less than 3 barrels); take out no less than 20 kg of product from the upper, middle, lower parts of each barrel; mix well; reduce it into 4 kg samples.

b) Divide the reduced 4 kg sample into three equal parts. Send one part to the arbitration organization, one part to the supplier, one part to the purchaser.

B.4.2 Preparation of test ingots

The pressing, casting, and preparation of each specimen of consumable electrode shall be carried out in accordance with B.2.2.

B.5 Inspection methods for appearance quality and particle size of titanium sponge

B.5.1 Appearance quality of titanium sponge

Randomly select 10% of the batch of product barrels (not less than 3 barrels; OR all of them when the batch is less than 3 barrels). Place them on a clean stainless steel plate.

Conduct visual inspection. Select defective titanium sponge block according to the provisions of 3.4.2. Weigh it, to determine whether its weight exceeds the requirements of this standard.

B.5.2 Particle size inspection method

B.5.2.1 Select a sieve that meets the requirements in accordance with the requirements of GB/T 6005. The basic size of the sieve holes shall correspond to the upper and lower limits of the product particle size requirements.

B.5.2.2 Randomly select 10% of the batch number of product barrels (not less than 2 barrels).

B.5.2.3 Place the two-layer sieves corresponding to the upper and lower limits of the product particle size requirements on the vibrating machine. Place the extracted product in the upper sieve in stages. Vibrate for 2 ~ 5 minutes. After confirming that the […]