GB/T 16507.5-2022Water-tube boilers - Part 5: Fabrication (English PDF)

5.1 Material marking

5.1.1 The material identification procedure for materials used for pressure components and main load-bearing components shall be formulated.

5.1.2 Boiler pressure parts (boiler drum, start-up (steam-water) separator, water storage tank, header parts, pipes with a nominal outer diameter of not less than 219mm) Material marks should be traceable to the quality certificate of the material; other pressure parts (pipes with a nominal outer diameter less than 219mm) and non-load bearing The material marks of the pressure parts (drum, start-up (steam-water) separator, water storage tank, supporting parts on the header) should be easy to identify, so as to prevent the mixing of materials.

5.2 Migration of material marks Material marking shall be retained during the manufacturing process. The materials used for boiler pressure components shall be marked and transplanted before cutting and cutting, and shall be easy to identify.

5.3 Marking during manufacture Welder marks, non-destructive testing (RT testing) marks, and material marks requiring traceability shall be retained as permanent marks. Production process When the middle mark is covered or the mark is lost due to processing, the mark should be transplanted.

5.4 Marking method

5.4.1 The following marking methods or a combination of the following methods should be used.

a) steel stamp (low stress steel stamp);

b) vibration etching or other etching tools;

c) Paint or mark with a marker.

5.4.2 The steel stamp shall not be used in the following situations.

a) stainless steel pipe;

b) In the inner and outer arc area of the pipe elbow;

c) Customer requests that material not be stamped.

5.4.3 When the method in

5.4.1 cannot be used for marking, other methods that do not damage the safety of the boiler can be used for marking (such as positioning maps, stickers, etc.).

6.1 General requirements

6.1.1 The manufacturing unit shall ensure that the actual thickness of the pressure component after processing or forming is not less than the minimum required thickness required by the design.

6.1.2 When using cold forming, the cold brittleness of the steel used should be considered.

6.1.3 When warm forming is used, the temper brittle temperature zone of the steel should be avoided.

6.1.4 The material forming process should consider the strain of the material. The manufacturing method used for cold forming should not cause excessive deformation rate of the component (or strain), otherwise the corresponding post-forming heat treatment should be carried out.

6.1.5 The materials used to manufacture end covers, flanges, pipe fittings, etc. shall comply with GB/T 16507.2 and design drawings.

6.2 Division of materials

6.2.1 Select the method of dividing the material according to the material properties and specifications. The segmentation method adopted should ensure the processing accuracy required by the process, and should also Reduce or avoid deformation caused by blanking. If the deformation exceeds the allowable range after blanking, appropriate methods should be used to correct it.

6.2.2 Determine whether preheating is required for thermal cutting according to the type and thickness of the steel. See Table 1 for the recommended preheating requirements.

6.2.3 The thermally cut surface shall be machined or polished to remove all burnt metal, cutting slag, harmful nicks and excess metal, etc. For alloy steel, a machining allowance should be left after thermal cutting, unless it can be shown that the structure of the material is not damaged.

6.3 Drum, starting (steam-water) separator, water storage tank, header body and head forming

6.3.1 Steel plates are used to manufacture cylinders and heads. When forging or stamping is used for manufacturing, it shall be carried out according to the requirements of forging heating control, and shall be connected with the pot. The production conditions of the furnace manufacturing unit are consistent.

6.3.2 The hot forming or cold forming manufacturing of the head shall adopt the continuous forming process.

6.3.3 The requirements for heat treatment after forming are as follows:

--- Cold forming of steel plate is shown in Figure

1.When the deformation rate is greater than 5%, corresponding heat treatment should be carried out after forming to restore the properties of the material. in accordance with Chapter 9;

a) For the rolled or pressed cylinder and the pressed head, the oxide scales, depressions and scars on the inner and outer surfaces shall be removed, and when the depth does not affect the When the minimum required thickness required by the design is in a smooth transition, it may not be ground; if the bottom is sharp, it should be ground to a smooth transition. ferry. When the depth affects the minimum required thickness required by the design, welding repair and grinding shall be carried out according to the qualified welding repair process, and no Damage inspection passed.

b) After the edge of the manhole is processed, it should be inspected on the surface, and there should be no cracks.

6.4.1 General requirements

6.4.1.1 Pipe forming includes pipe bending and pipe end forming. If the cold forming of the pipe cannot meet the technical requirements of the product, hot forming should be used.

6.4.1.2 The requirements for heat treatment after forming of the pipe shall be in accordance with the provisions in

6.4.4 and Chapter 9.

6.4.2 Elbows

6.4.2.1 Thermoforming (that is, hot bending, including inner heating bends, inner heating bends, Hot extrusion forming and intermediate frequency induction heating bending, etc.) or cold forming (ie cold bending).

6.4.2.2 When hot bending is used, the heating specification and heating range shall be strictly controlled.

6.4.2.3 The bending process test should be carried out for the bent pipe to verify that the adopted bending process meets the technical requirements of the product. Bending process test can refer to According to Appendix A.

6.4.2.4 After the pipe is bent, the thinning rate, the minimum wall thickness of the inside and outside of the elbow, the roundness of the elbow, the deviation of the bending angle and the surface quality shall be inspected, and conform to Requirements of 6.4.2.5~6.4.2.9.

6.4.2.5 The thinning rate of the elbow and the wall thickness of the inside and outside of the elbow shall meet the following requirements.

a) Thinning of the outside of the elbow After the pipe is bent, the thickness of any point outside the elbow shall not be less than the calculated value of formula (3).

6.4.3 Tube end forming

6.4.3.1 In order to satisfy the splicing of pipes with different wall thicknesses or pipes with different calibers, the pipe ends can be formed by upsetting, necking and flaring.

6.4.3.2 After the pipe end is upset, necked and flared, the outer surface of the pipe and the transition zone of wall thickness should be smooth and free of cracks.

6.4.3.3 The control of the upsetting thickness, necking and flaring of the pipe end and the heat treatment after forming shall be carried out according to the verified process, and it shall be ensured that no damage will be caused. performance of hazardous materials.

6.4.4 Heat treatment after pipe forming

6.4.4.1 The general requirements are as follows:

a) All cold-bending and hot-bending elbows, including cold-bending and hot-forming elbows, shall comply with the provisions of 6.4.4.1b), and shall also comply with 6.4.4.2~

6.4.4.3 requirements for heat treatment;

b) For carbon steel (Fe-1) pipes and 09CrCuSb (ND steel) pipes, if the hot forming is within the normalizing range specified in the corresponding material standards If carried out, heat treatment is not required;

c) For all cold-formed elbows whose thinning rate exceeds 25%, heat treatment shall be carried out in accordance with the requirements of the corresponding material standards after bending.

6.4.4.2 For cold-formed pipes, the requirements for heat treatment are as follows:

a) Ferritic steel When the strain at the elbow is greater than 38.5%, post-bending heat treatment should be performed. Pipes made of 10Cr9Mo1VNbN (Fe-5B-2) and 10Cr9MoW2VNbBN (Fe-5B-2) should be designed according to their design temperature. Corresponding heat treatment should be carried out according to the degree and strain after forming. The recommended heat treatment requirements after cold bending are shown in Table 2.

6.4.4.3 For bent pipes that are hot-bent, the requirements for heat treatment are as follows:

a) Ferritic steel All hot-bent elbows, including cold-bending and hot-shaping elbows, should be subjected to corresponding heat treatment in order to restore the material properties to the best state. For pipes made of 10Cr9Mo1VNbN (Fe-5B-2) and 10Cr9MoW2VNbBN (Fe-5B-2), the overall normalizing and tempering heat treatment should be carried out after hot bending. For other types of materials, the post-bending heat treatment process can be determined by each manufacturing unit according to factors such as material type, outer diameter, and wall thickness.

b) Austenitic steel Austenitic steels should be solution treated after hot bending (including double forming), and should be properly accelerated cooling with water and air according to the material specification.

6.4.4.4 The requirements for heat treatment after pipe end forming are as follows:

a) Ferritic steel The material is 10Cr9Mo1VNbN (Fe-5B-2), 10Cr9MoW2VNbBN (Fe-5B-2) pipe ends after cold and hot forming The overall normalizing and tempering treatment should be carried out.

b) Austenitic steel Austenitic steel pipe ends should be solution treated after cold and hot forming.

c) For materials other than 6.4.4.4a) and b), the heat treatment after the pipe end is formed can be determined according to the manufacturing process.

6.5.1 Drum, start (steam water) separator, water storage tank

6.5.1.1 The actual edge deviation value of the steel plates on both sides of the longitudinal seam of the cylinder or the spliced weld of the head shall not be greater than the nominal thickness of the plate (take the steel plate on both sides of the weld 10% of the thinner plate), and not exceeding 3mm; when the nominal thickness of the plate is greater than 100mm, not exceeding 6mm.

6.5.1.2 The actual edge deviation of the steel plates on both sides of the circular joint (including the plate thickness difference) shall not be greater than 15% of the nominal thickness of the plate plus 1mm, and not more than 6mm; when the nominal thickness of the plate is greater than 100mm, it should not exceed 10mm.

6.5.1.3 The centerlines of the steel plates on both sides of the longitudinal and annular seams of the cylinder should generally be aligned. When the steel plates on both sides of the annular seam of the cylinder are not together. When the steel plates on both sides of the longitudinal and circular seams of the cylinder (including steel plates with different nominal thicknesses on both sides) are butted, the nominal edge difference of any one of the two sides exceeds If the edge deviation value specified in this document is exceeded, the edge of the steel plate on the thicker side shall be cut to be flush with the steel plate on the other side, or the steel plate on the thinner side shall be stacked Weld until it is flush with the steel plate on the other side. The chamfered or surfacing slope shall be smooth, and the slope shall not be greater than 1.3.If necessary, the width of the weld can be calculated within the slope. When the thinning method is used, the actual wall thickness of the component after thinning shall not be less than the design requirements calculated according to the provisions of GB/T 16507.4. Find the minimum required thickness.

6.5.1.4 The difference between the maximum inner diameter and the smallest inner diameter on any same cross-section of the cylinder should not be greater than 1% of the nominal inner diameter.

6.5.1.5 For the edges and angles E formed in the circumferential and axial directions of the welded joints, it is advisable to use inner templates with chord lengths equal to Di/6 and not less than.200mm respectively. (or outer template) and ruler inspection (see Figure 3, Figure 4). For the circumferential edges and corners formed by the longitudinal seams, the E value shall not be greater than (deltas/10 2)mm, and shall not be larger than less than 4mm; the axial edges and corners shall be thinned or surfacing according to 6.5.1.3.

6.5.3.1 Butt joint edge deviation 6.5.3.1.1 The inner walls of the grooves of butt joints shall be aligned and flush. When the nominal outer diameter and nominal wall thickness on both sides of the joint are equal, the heating surface tube The edge deviation of the outer surface of the butt joint shall not exceed 10% of the nominal wall thickness of the pipe plus 0.5mm, and the maximum shall not exceed 1mm; The edge deviation of the outer surface of the component shall not exceed 10% of the nominal wall thickness plus 0.5mm, and the maximum shall not exceed 4mm. When the outer diameter is different and the edge deviation exceeds the limit, the excess part should be thinned. 6.5.3.1.2 The edge deviation of the inner surface of the butt joint shall not exceed 10% of the nominal thickness plus 0.5mm, and the maximum shall not exceed 1mm. Parts should be internally bored or thinned. 6.5.3.1.3 The thinning requirements when the edge deviation of the butt joint is out of tolerance shall be in accordance with 6.5.1.3.

6.5.3.2 Dimensional deviation of pipes and pipes For pipes and pipes with elbows, the dimensional deviation between their two ends should be controlled to facilitate installation.

6.5.3.3 Size deviation of header components The length deviation and straightness deviation of header parts shall meet the requirements in Table 6.

6.5.3.4 Pipe joint deflection

7.6.3 Pipe wall thickness reduction rate control method When the control method of pipe wall thickness reduction rate is adopted, the following requirements shall be met.

a) During the test expansion work before expanding the tube, the torque setting should be set for each combination of tube specifications and wall thickness.

b) Torque setting is achieved by expanding the test tube into the tube hole of the test plate. After the test tube expansion is completed, open the test plate and take out the test tube measuring tube Then calculate the pipe wall thinning rate, the pipe wall thickness thinning rate is generally controlled within the range of 10%~12%, the torque setting

7.7 Expansion quality

7.7.1 The protruding length of the pipe end should be in the range of 6mm~12mm, and the included angle between the edge of the bell mouth of the pipe end and the center line of the pipe should be 12°~ Between 15°, the starting point of the flange should be flush with the surface of the drum, and there should be a clear boundary from the expansion part to the bell mouth part, and there should be no obvious incision and extrusion.

7.7.2 The end of the expanded pipe should not have defects such as peeling, wrinkles, cracks, cuts and deflection.

7.7.3 There should be no cracks on the pipe end flanging and the edge of the bell mouth, and the transition from the expanded part of the inner wall of the expansion joint to the unexpanded part should be uniform, flush, and free of cuts and grooves.

7.7.4 Expansion records should be made according to the actual inspection and measurement results.

7.7.5 After all the expansion joints are completed, a hydraulic test should be carried out to check the tightness of the expansion joints.

8.1 General requirements

8.1.1 Manufacture and repair boiler pressure components and load-bearing components by means of welding. For welding between pressure components and load-bearing components, manufacturing The manufacturing unit shall formulate a welding process that meets the requirements and the corresponding inspection and acceptance requirements to ensure the welding quality.

8.1.2 Electroslag welding should not be used for boiler pressure components.

8.2 Welding procedure qualification

8.2.1 Requirements for butt-welded joints between pressure components, connections between pressure components or between pressure components and load-bearing non-pressure components The welding process used for full penetration T-joints or fillet joints shall be carried out in accordance with NB/T 47014 and the additional requirements in Chapter 8 of this document Evaluation. The welding process adopted by the boiler membrane tube panel shall be evaluated according to the requirements of Chapter 8 and Appendix B. NB/T 47014 and this document For welding methods that are not involved, the manufacturing unit shall formulate welding procedure qualification procedures that meet product technical requirements for welding procedure qualification.