Wire Rod

YORGEE INSPECTION

High-quality Carbon steel No-Twist Wire Rod with Controlled Cooling

1. Scope

This standard has regulations on dimension, figuration, weight, permissible deviation, technical requirement, testing method, inspection procedure, package, label, quality certificate and etc of high-quality carbon steel no-twist wire rods with controlled cooling.
This standard applies to high-quality carbon steel no-twist wire rods with controlled cooling, used for producing high-carbon steel wire, high-strength wire, prestressed steel wire and steel strand, galvanized steel wire, galvanized stranded wire, tire bead steel wire, rubber-pipe steel wire, steel wire rope, carbon spring steel wire and oil-quenching and tempering carbon spring steel wire, etc.

1. Standard Quoted

Clauses below in the paragraph serve as clauses of this Standard by being quoted in the Standard. When the Standard is published, all editions are effective. All standards shall be revised and parties using the Standard should discuss the possibility of using the latest edition of the following standards.
GB 222-84 Sampling Method for iron& steel chemical analysis and permissible deviation for product chemical composition
GB 223 chemical analysis method for iron, steel and alloy
GB 224-87 Determination method of depth of decarburization of steel
GB 224-87 Method of tensile test for metals
GB 232-88 Method of bending test for metals
GB 233-82 Method for forging test of metals
GB 1222-84 Spring steel
GB 2975-82 Rules for sampling in mechanical and technological testing of steel products
GB 6397-86 tensile test sampling for metals
GB 10561-89 Micro-rating method of non-metal foreign substance in steel
GB/T 13298-91 Test method for metal microstructure
JIS G3506: 1996 High carbon steel wire rod
Q/BQB 501-1998 dimension, figuration, weight and permissible deviation of no-twist wire rods with controlled cooling
YB/T 5148-93 Metal-methods for estimating the average grain size

1. Dimension, figuration, weight and permissible deviation

Dimension, figuration, weight and permissible deviation shall meet the rules of Q/BQB 501.

1. Technical requirement
1.  Grade and chemical composition
1. Grade and chemical composition shall meet rules in Table 1.
2. The permissible deviation between product chemical composition of wire rod and specified value in Table 1 shall meet rules in GB 222.
3. On the basis of requirements of demander and agreement between demander and supplier, wire rods of other grade and chemical composition can also be supplied.

Table 1

1.  Smelting process

Steel is smelted in oxygen blown converter and electric furnace. The supplier will determine the smelting process if the demander has no specific requirements.

1.  Delivery condition

Wire rods are delivered in hot-rolling condition.

1.  Decarburized layer

In decarburized depth test for rods of steel with carbon content of more than 0.60%, total decarburized depth (ferrite+ transitional layer) on one side of wire rod shall not exceed 1.5％ nominal diameter of wire rods.
On the basis of requirements of the demander, decarburized depth test can also be applied to wire rod of steel with carbon content of more than 0.30% and the norm is determined on the basis of agreement between both parties.

1.  Grain size

Actual grain size of wire rod of steel with carbon content of more than 0.60% should be tested and it shall be grade 6-8.

1.  Microstructure

Wire rods shall not have quenched structure (marten-site and troostite area). If the supplier can guarantee their process, test can be omitted.

1.  Surface quality
1. The surface of wire rods shall be smooth and with no crackle, fold, lap, ear and other defects bad for use. Pressmark and local cam, pit, scratch and bit are permissible. But the depth or height of them shall: no more than 0.15mm for precision degree A, and no more than 0.10mm for precision degree A and B.
2. Defected heading and ending of wire rods shall be cut off, and the section shall not have sunk spot, layers or foreign substance.
3. Oxide scale

The weight of oxide scale of wire rod shall be no more than 10kg/t. If the supplier can guarantee their process, test can be omitted.

1.  Special requirements

On the basis of requirements of demander and agreement between demander and supplier, they can do mechanical property test, bending test, cold forging test, non-metal foreign substance test or test for other purposes. The norm is determined on the basis of agreement between both parties.

1. Test method
1. Tested item, sample quantity, sampling part and test method for every batch of wire    rods shall be implemented according to rules in Table 2.

Table 2

1.  Test method of oxide scale

Take samples of one or some coils of wire rods to weight them, remove the oxide scale with mechanical method and weight again. The weight differential is the weight of oxide scale of samples.
         The computing formula for oxide scale weight of every ton of wire rods:
         Weight of oxide scale of sample (kg)/weight of sample (kg) X 1000(kg/t)

6　Inspection Rules
6.1　Check & Accept
Check & accept for wire rod shall be completed by technical supervision department of supplier.
6.2　Sets of batch rules
Wire rod shall be checked in batches. In addition, each batch is comprised of wire rods with the same grade, number of stove and dimension.
6.3　Re-inspection and confirmation rules
If chemical composition (ingredient of product) can not meet requirement of standard, some measures should be taken, involved rejecting unqualified wire rod and getting any double quality of sample in the same batch to re-inspect. Even though just an item indicates unqualified among re-inspection results (including any one item required test), supplier may analyze bunch by bunch. Ultimately, it can be delivered when qualified.
7　 Packing, Sign and Quality Certificate
7.1　Packing
Wire rod should be delivered in bunches. In addition, each bunch is comprised of a whole wire rod with not less than 3 straps.
7.2　Sign
Wire rod per bunch should be attached to 2 labels at least, which will provide supplier’s name, grade, number of stove, rolling and bunch, specification, weight, technical standard, and etc.
7.3　Quality Certificate
Wire rod per batch for delivery must have quality certificate which is subject to relevant standards and contract for goods. The following is indicated in the certificate:
(1)　Supplier’s name
(2)　Name of company for goods
(3)　Delivery date
(4)　No. of contract
(5)　Standard S/N
(6)　Grade
(7)　No. of stove, weight
(8)　Name of product and its specification
(9)　Each test result according to standard
(10) Seal of technical supervision department