JB/T 6880.1-2013Grey iron castings for pumps (English PDF)

5.1 Production method and chemical composition

The production method and chemical composition shall comply with the provisions of

6.1

and 6.2 of GB/T 9439-2010.

5.2 Mechanical properties

The mechanical properties shall comply with the provisions of 7.1 of GB/T 9439-2010.

5.3 Metallographic structure

The metallographic structure shall comply with the provisions of 7.2 of GB/T 9439-

2010.

5.4 Heat treatment

Castings shall be subjected to stress relief annealing treatment. The specific requirements shall be agreed upon by the supplier and the buyer.

5.5 Geometric shape and size

The geometric shape and size of the casting shall comply with the requirements of the drawing.

5.6 Dimensional tolerance

5.6.1 The dimensional tolerance of general parts shall not be less than that specified in

Table 1; the tolerance zone shall be set symmetrically to the basic size of the casting.

5.6.2 When the dimensional tolerance specified in Table 1 cannot meet the requirements

OR when the casting is a small batch or a single piece and it must consider economic factors, it shall be specified separately in the drawing or the agreement agreed by both

6.8 Casting defects

The inspection of casting defects shall be carried out in accordance with the provisions of 7.8 of GB/T 9439-2010.

6.9 Inspection of special requirements

The inspection of special requirements shall be carried out in accordance with the provisions of 5.12 of this standard, in accordance with the agreement or relevant provisions agreed upon by the supplier and the buyer.

6.10 Inspection of defect welding repair

The inspection of welding repair of casting defects shall comply with the provisions of

Appendix A.

7.1 Inspection rights

The inspection rights shall be carried out in accordance with the provisions of 10.1 of

GB/T 9439-2010.

7.2 Inspection location

The inspection location shall be carried out in accordance with the provisions of 10.2 of GB/T 9439-2010.

7.3 Division of sampling batches

The division of sampling batches shall be carried out in accordance with the provisions of 10.3 of GB/T 9439-2010.

7.4 Inspection items

The inspection items are:

a) The tensile test shall be carried out in accordance with the provisions of 9.1 of

GB/T 9439-2010;

b) The hardness test shall be carried out in accordance with the provisions of 9.2 of

GB/T 9439-2010;

c) The metallographic examination shall be carried out in accordance with the provisions of 9.6 of GB/T 9439-2010.

7.5 Evaluation of test results

The evaluation of test results shall be carried out in accordance with the provisions of

10.5

of GB/T 9439-2010.

7.6 Inspection of geometric shape and size

The geometric shape and size of the casting shall be inspected according to the drawings.

The first batch of castings and important parts shall be inspected piece by piece according to the drawings. General castings and castings produced by the method of ensuring dimensional stability can be spot checked; the sampling method shall be agreed upon by the supplier and the buyer.

7.7 Dimensional tolerance of castings

The dimensional tolerance of castings shall be inspected in accordance with the requirements of 5.6. The inspection rules shall be implemented in accordance with the provisions of 7.6.

7.8 Shift value

The shift value shall be inspected piece by piece according to the requirements of 5.7.

7.9 Machining allowance

The machining allowance shall be inspected according to the requirements of 5.8. The inspection rules shall be implemented in accordance with the provisions of 7.6.

7.10 Weight

The weight and weight tolerance of castings shall be spot checked in accordance with the requirements of 5.9.

7.11 Surface quality

The surface quality shall be inspected piece by piece according to the requirements of

5.10

of this standard. The surface roughness inspection of castings shall be implemented in accordance with the provisions of GB/T 6060.1.

7.12 Defect inspection

The inspection of casting defects shall be carried out piece by piece according to the requirements of 5.11.

7.13 Special inspection

The inspection of special requirements shall be carried out piece by piece according to the requirements of 5.12.

7.14 Welding repair inspection

Appendix A (Normative)

Welding repair of gray cast iron parts for pumps

A.1 General

This Appendix specifies the welding repair method, welding repair procedure, welding repair inspection of gray cast iron parts for pumps (hereinafter referred to as castings).

This Appendix is applicable to gray cast iron parts for pumps, that have no special provisions or special requirements for welding repair in drawings or other technical documents. Welding repair of ductile iron parts for pumps can also make reference to this Appendix.

A.2 Welding repair permit conditions

A.2.1 When a casting needs to be welded, the consent of the relevant functional department shall be obtained.

A.2.2 The permit conditions for castings that need to be welded shall comply with the provisions of 4.12.

A.2.3 According to its performance, for important components or locations or important

parts and locations that must be considered for safety factors, the welding repair notice procedures approved by the technical person in charge shall be followed when welding.

The welding repair notice shall include the following contents:

a) Defect situation;

b) Welding repair method;

c) Inspection method;

d) Whether stress relief treatment or annealing treatment is performed after welding (as needed);

e) Whether welding repair records are required (as needed).

A.3 Welding repair method and scope of application

A.3.1 Gas welding method

Gas welding method is a welding repair method, that uses oxygen and acetylene as heat sources to melt the electrode and the matrix. When welding with this method, the according to the matrix with a grinding wheel or other methods, to confirm whether there are welded defects. Whether non-destructive testing is required can be determined based on design requirements and strength properties.

A.5 Welding repair inspection

A.5.1 Pre-welding preparation

A.5.1.1 Check the size and nature of defects.

A.5.1.2 Defects shall be completely removed. If arc welding is used for welding, the groove shape shall comply with the provisions of A.4.2.1 b).

A.5.1.3 The defect removal area and its vicinity shall be clean; there shall be no oil or dirt that affects the quality of the welding repair.

A.5.2 Post-weld inspection

A.5.2.1 For welding repairs that require stress relief after welding, post-weld inspection

shall be carried out after stress relief heat treatment.

A.5.2.2 The grinding and finishing of the welding repair area shall meet the requirements of being able to confirm whether there are welding repair defects.

A.5.2.3 If the welding repair area is on the non-machined surface, the welding repair area shall be repaired and leveled according to the matrix.

A.5.2.4 The welding repair shall meet the quality requirements; there shall be no welding repair defects after welding. In addition to the necessary non-destructive testing, generally only visual appearance inspection is carried out.

A.5.2.5 For castings that are subjected to liquid pressure or gas pressure, a water pressure test or air pressure test for air tightness shall be carried out after the welding repair.

A.5.3 Records

A.5.3.1 According to the requirements of the welding repair notice, for the castings that need welding repair records, it shall write operating records; send the welding repair notice and operating records to the quality inspection department for archive.

A.5.3.2 The items, contents, format of the welding repair notice and welding repair

record are as shown in Table A.5, for reference.