JB/T 8583-1997Resin coated sand for foundry (English PDF)

3.1 hot bending strength

The sample is heated to 232 °C ± 5 °C, and the bending strength is measured within 10 s after taken out from the mold.

3.2

5.1 Required performance indicators

The performance indicators that must be tested for resin coated sand for foundry include room temperature bending strength, hot bending strength, loss on ignition, average fineness and melting point.

5.1.1

The room temperature bending strength shall comply with the provisions of Table

1.

5.1.2

The loss on ignition shall comply with the provisions of Table 2.

5.1.3

The melting point is 85 °C ~ 110 °C.

5.1.4

The hot bending strength is 1.5 MPa ~ 5.0 MPa.

5.1.5

The determination and calculation method of the average fineness shall be carried out according to the provisions of GB/T 9442.

5.2 Optional performance indicators

5.2.1

The optional performance indicators of resin coated sand for foundry include room temperature tensile strength, hot tensile strength, gas evolution volume, fluidity and hardening rate.

5.2.2

If the buyer has special requirements for the performance indicators in 5.2.1 and other performance indicators, both the supplier and the buyer shall specify in the order agreement.

6.1

See Appendix A for the test methods for room temperature bending strength, hot bending strength, loss on ignition, average fineness and melting point of resin coated sand for casting.

6.2

See Appendix B for the test methods for room temperature bending strength, hot tensile strength, gas evolution volume, fluidity and hardening rate of resin coated sand for foundry.

7.1 Sampling

7.1.1 Division of batches

It is divided by tonnage; each continuous production of 10 t is a batch.

7.1.2 Sampling method

When sampling the resin coated sand in each batch, it can select the average sample from the same batch of well-packaged resin coated sand. The average sample of the bagged resin coated sand is selected from 1 % of the same batch, but it shall not less than 3 bags at least and shall not be less than 5 kg in weight. The sample required for the inspection are selected from the total sample using the “quarter method” or riffle sampler. If there is any doubt about the quality of a certain part of the resin coated sand, it shall be sampled and inspected separately.

7.2 Inspection

The inspection method for resin coated sand shall be carried out according to the provisions of Clause 6. The optional performance indicators or other special performance requirements specified in this Standard shall be determined through negotiation between the supplier and the buyer. Each batch of resin coated sand from the supplier shall be inspected according to the required performance indicators specified in this Standard, and the inspection results and designation shall be written into the quality report and delivered to the buyer with the product. The buyer may carry out the acceptance inspection according to the technical requirements of this Standard or the provisions of the agreement.

7.3 Re-inspection

If one of the indicators fails in the inspection result, the sample shall be doubled for re- inspection, and the re-inspection result is the final result. If the re-inspection results still do not meet the indicators specified in this Standard, the batch of products is determined to be unqualified.

7.4 Arbitration test

In the event of a dispute over quality between the supplier and the buyer, they may negotiate or entrust a third party selected by both parties to conduct arbitration.

8.1

The packaging bag of resin coated sand for foundry shall be moisture-proof and easy to transport.

8.2

The packaging bag shall be marked with:

a) The words “resin coated sand”;

b) Designation;

The determination of the room temperature bending strength value of the sample is carried out according to the provisions of GB/T 2684. The bending strength value is 16 times the tensile scale value in the pressure gauge.

NOTE: See Appendix B for another test method for room temperature bending strength of resin coated sand for foundry.

A.2 Hot bending strength

The preparation of the sample for hot bending strength shall be carried out according to the provisions of A.1.

For the determination of hot bending strength, the sample is prepared according to the provisions of A.1.After the sample is taken out, it is placed on the testing machine immediately; gradually load until the sample breaks. It is required that the test is completed within 10 s after the sample is taken out. The bending strength value is 16 times the tensile scale value in the pressure gauge.

A.3 Loss on ignition

A.3.1 Device

a) High-temperature box-type resistance furnace;

b) Balance (sensitivity 0.001 g);

c) Porcelain boat.

A.3.2 Procedure

Firstly, PLACE the porcelain boat that has been roasted to constant weight at 1000 °C

± 5 °C for 30 min IN a desiccator; COOL to room temperature for later use; WEIGH the porcelain boat. WEIGH 2 g (accurate to 0.001 g) of resin coated sand sample to be tested and PLACE it in the roasted porcelain boat; WEIGH them. Then PUT them together in a high-temperature box-type resistance furnace that has been heated to

1000 °C ± 5 °C to ROAST for 30 min. TAKE OUT the porcelain boat and PLACE it in a desiccator; COOL to room temperature; WEIGH it again.

A.3.3 Presentation of results

The loss on ignition D (%) is calculated according to formula (A.1):

where:

W0 - the mass of the empty porcelain boat that has been roasted to constant weight, in g;

For the determination of hot tensile strength, the sample is prepared according to the provisions of A.2. After the sample is taken out, it is pulled off on the testing machine immediately. It is required that the test is completed within 10 s after the sample is taken out. The measured value multiplied by 2 is the measured hot tensile strength of the sample.

B.3 Liquidity

B.3.1 Device

Phi6 mm standard flow cup.

8.3.2 Procedure

PLUG the bottom hole of the standard flow cup with your hand; then FILL with the resin coated sand and SCRAPE to flatness; REMOVE your fingers and START timing with a stopwatch at the same time until the sand flows out.

8.3.3 Presentation of results

The time counted by the stopwatch is the fluidity measured value of the sand, in s.

B.4 Gas evolution volume

B.4.1 Device

a) SFL recording gas evolution volume measuring instrument;

b) Balance (sensitivity 0.001g);

c) Porcelain boat.

B.4.2 Preparation and preservation of sample

The sand ground at the fracture of the sample for the room temperature tensile strength of resin coated sand is used as the sample for measuring the gas evolution volume. It is stored in a desiccator.

B.4.3 Procedure

HEAT the gas evolution volume measuring instrument to 1000 °C ± 5 °C; WEIGH 1 g

± 0.01 g of the sample; PLACE it evenly in a porcelain boat (the porcelain boat is pre- burned at 1000 °C ± 5 °C for 30 min and then placed in a desiccator to cool to room temperature for later use). Then, quickly SEND the porcelain boat to the red-hot part of the quartz tube; SEAL the opening of the tube. The recorder began to record the gas evolution volume of the sample. The maximum data recorded by the measuring instrument is read within 3 min as the gas evolution volume of the sample.

B.5 Room temperature bending strength

GB/T 8263 | GB/T 8492 | JB/T 5106 | […]