Pipe standard terminology

 1) The generic term

 

① delivery status

Is the final plastic deformation refers to the delivery of products or the status of the final heat treatment. Generally do not heat-treated to delivery of said hot-rolled or cold drawn (rolled) or manufactured state; said heat treatment after heat treatment delivery status, or according to the type of heat treatment that normalized (normalization), quenching and tempering, solution annealing state. When ordering, delivery status specified in the contract.

 

② According to the actual weight of the delivery or delivered according to theoretical weight

Delivery of the actual weight - the weight of their products by weighing (weighing) the weight of delivery;

Theoretical weight - the time of delivery, the weight of their products is said that the size calculated from the weight of steel public. The following formula (which requires the theoretical weight of delivery to be specified in the contract):

Steel pipe per meter of the theoretical weight (density of steel for 7.85kg/dm3) formula:

W = 0.02466 (D-S) S

Type: W - steel pipe per meter theoretical weight in kg / m;

- The public of the steel pipe nominal diameter, mm;

S - the public of the steel pipe wall thickness, mm.

 

③ warranty conditions

Tested according to the provisions of the current standards projects and ensure that the provisions of the standard, called the warranty conditions. The guarantee conditions are divided into:

A basic guarantee for the condition (also known as a necessary condition). Regardless of whether the customer specified in the contract. Need to be carried out in accordance with the standard provisions of the survey, and to ensure that test results meet the standard requirements.

Process performance, such as chemical composition, mechanical properties, dimensional deviation and surface quality, as well as crack detection, hydrostatic test, or flattening or flaring and other experiments are a necessary condition.

B, the agreement will guarantee conditions: standard, in addition to the basic guarantee for the condition, there are "demand-side requirements, negotiated by supply and demand, and in the contract note? Quot; or" demand-side requirements ...... in the contract note out "; some customers, the standard basic guarantee for the conditions of tightened requirements (such as composition, mechanical properties, size deviation, etc.) or increase the test items (such as seam STEEL TUBES ovality, uneven wall thickness, etc.) The above terms and requirements. when ordering by supply and demand, both parties signed supplier agreement and indicate in the contract. Therefore, these conditions are also known as the agreement to ensure that conditions there is an agreement to guarantee the conditions of the product, generally fare increase.

 

④ approved

Standard "lot" means an inspection units, namely the inspection lot. If the batch delivery unit group, said the consignment. When the volume delivery, a consignment may include several test batches; delivery batch came from an inspection lot can be divided into several consignments.

 

"Batch" of the composition usually have the following provisions (see the relevant standards):

A, each batch should be the same grade (steel grade), the same stove (pot) or the same mother furnace of the same specifications and the same heat treatment (furnace) steel.

Quality carbon steel tubes, fluid tubes, can be the same grades of the different furnaces (cans) of the same specifications and the same heat treatment (furnace) steel.

Welded steel pipe of each batch should be the same grade (steel grade), of the same specifications of the steel pipe.

 

⑤ high quality steel and high quality steel

GB/T699-1999 and GB/T3077-1999 standard grades behind with the letter "A" who, for the high quality steel, contrary to the generally high quality steel.

High quality steel in the following part or all of the superior to high-quality steel:

A narrow composition content range;

B, to reduce the harmful elements (such as sulfur, phosphorus, copper) content;

C to ensure high purity (non-metallic inclusion content of less);

D, to ensure high mechanical and technological properties.

 

The ⑥ vertical and horizontal

The standard longitudinal means parallel to the machining direction (ie, along the processing direction) who said; horizontal is perpendicular to the machining direction (machining direction of the steel tube axial).

Do impact energy experiment, the longitudinal sample of the fracture surface perpendicular to the machining direction. It is called a transverse fracture; the fracture of the transverse specimens parallel with the processing direction, it said longitudinal fracture.