Tension Test of Anchor Chain

According to the chain structure, anchor chain is divided into two kinds of stud chain and non-stud chain. When the size and material are the same, the stud chain deformation is small, it is not easy to twist when stacking, and it is not easy to wind when anchoring, so it is widely used on sea ships.

The anchor chain or accessories shall be subjected to the necessary heat treatment according to its grade and delivery condition before tensile test, tensile break test and mechanical properties test of the finished anchor chain material.

Tensile and breaking tests of all finished anchor chains shall be carried out in accordance with the relevant requirements and standards of the code:

(1) Tensile test: It is a tensile test for each ring of the whole chain. Each chain shall be tested on an approved test machine according to the tensile load specified for the chain of the corresponding grade. During the test, the relative position of each link is correct, and the whole chain must not be twisted. When the load is removed, each chain, including its dimensions, shall be inspected and there shall be no obvious defects. The appearance, size and relative rotation flexibility of links and accessories should be carefully checked, and the permanent elongation should not exceed 5% of the original length.

(2) Breaking test: One shot anchor chain shall be selected from every four anchor chains according to the specified number of samples (AM2 and AM3 grade anchor chains shall be a batch of every 4 shot welded anchor chains; Each batch is not more than 4 shots of anchor chain), cut the sample of not less than 3 chain links, and test according to the tensile load specified in the code. The test link should be made in the same manufacturing process as the anchor chain and welded and heat-treated together with the anchor chain. The test link should be removed from the anchor chain in the presence of the surveyor.

The test is considered to have passed if no breakage occurs after the prescribed load has been applied. If the breaking test does not meet the requirements, two more samples can be taken on the same section of the anchor chain for test, if it can meet the requirements, it is considered that the test is qualified. If the second test is still unqualified, the anchor chain shall be judged as unqualified. However, according to the requirements of the manufacturer, the remaining 3 sections of the anchor chain are respectively pulled off the test, if one of the test results does not meet the requirements, then all 3 sections of the anchor chain are unqualified.

If the mechanical properties of the chain link are unqualified, they can be resampled after heat treatment, and if they are still unqualified after a second test, the anchor chain shall be judged as unqualified.

The anchor chain accessories should generally be tensile test and break test in accordance with the relevant provisions (except for those who agree to exempt the test), where the accessories that have done the break test can not be used.

After the anchor chain test passes, the anchor chain grade, certificate number and classification society's mark shall be stamped on both ends of each anchor chain.