| |
Certficate
 |
|
|
Home Quality Control |
   |
| Quality Control |
Potential Failure Mode and Sequel Analysis
According to the standard TS16949-2009, our technicians had been organized to analyze carefully and scientifically the potential failure mode and the possible results upon all the process steps among the whole production. Therefore, any factors in the production which may affect the product quality and cause invalidation can be treated in advance. |
 |
Quality Control Standards for Double Wall Steel tubes Electrical Welded
Item # |
Characteristic |
method |
requirements |
Specification |
Quantity tested |
1 |
Strip certificate: |
|
|
|
|
2 |
chemistry of steel |
supplier |
SAE 1006/1008 grade |
SAE J527/CAL103 |
per heat # |
3 |
mechanical properties |
supplier |
30T scale: 35-45 |
CAL-103 |
per master coil |
4 |
Copper thickness |
supplier |
2.5 - 3 microns |
CAL-103 |
per master coil |
5 |
Tubing certificate |
|
|
|
|
6 |
Tube OD histogram |
micrometer |
Cpk = 1.33 minimum of tolerance range +/-0.07 mm |
SAE J527 |
per mill#pallet |
7 |
Wall thickness |
micrometer |
+/-0.07 mm |
SAE J527 |
per mill#pallet |
8 |
Coil Appearance |
visual |
no scratches, stains |
SAE J527 |
per mill#pallet |
9 |
Bevel height |
transverse section |
0.05 mm max |
CAL-009 |
per mill#pallet |
10 |
Overlap length |
transverse section |
> 0.64 mm |
CAL-009 |
per mill#pallet |
11 |
Braze joint integrity |
transverse section |
no porosity at the bevel |
CAL-009 |
per mill#pallet |
12 |
Tensile Strength |
tensile test |
290 Mpa |
SAE J527 |
per mill#/Master Coil |
13 |
Elongation in 2 inch gage length |
tensile test |
4.75 mm (3/16") O.D.: 17% minimum |
CAL-009 |
per mill#/Master Coil |
6.35 mm O.D.(1/4") : 21% minimum |
CAL-009 |
per mill#/Master Coil |
7.9 mm (5/16") O.D.: 25% minimum |
CAL-009 |
per mill#/Master Coil |
14 |
Flaring test |
press |
35% minimum expansion with no flaws or cracks |
CAL-009 |
per mill#/Master Coil |
15 |
Flattening test |
Vice |
no flaws or cracks at the seam |
SAE J527/J1677 |
per mill#/Master Coil |
16 |
Burst test |
Burst tester |
4.75 mm (3/16") O.D.: 110 MPa minimum |
CAL-009 |
per mill#/Master Coil |
6.35 mm O.D.(1/4") : 82.8 MPa minimum |
CAL-009 |
per mill#/Master Coil |
7.9 mm (5/16") O.D.: 75.9 MPa minimum |
CAL-009 |
per mill#/Master Coil |
17 |
Cleanliness test |
Solvent, Analytical balance |
0.2 gram/m 2 maximum; with no dark carbon deposit |
CAL-009 |
per mill#pallet |
18 |
Non-Destructive Test |
Eddy Current Tester |
No Braze Inconsistencies. No Holes. No Cracks |
SAEJ527/ SAEJ1737 |
100% |
Inspection on raw material in factory |
Operation Process Control
 |
 |
The welding of the steel strip joint is carefully finished as per operation guide to ensure the joint solid and the same thickness between the original strip and the overlap part . |
|
 |
The bevel edge rolling is strictly made according to the operation guide so that the bevel thickness and strip width can meet the technical terms . |
|
 |
7 points control is executed as per operation guide
. |
|
 |
The welding temperatures are set as per operation guide
. |
|
 |
Adjust the cool water flux in term of the operation guide so that the tube can be cooled to the requested temperature
. |
|
 |
Properly adjust the drawing force and the drawing wheel pressure according to the operation guide so that there are no slip and deform of the tubes during the process
. |
|
 |
The detecting precision is set according to the operation guide to ensure there are no wrong points or missing points during the process
. |
|
 |
Passivation treatment is made on the tube surface to avoid its oxidation
. |
|
 |
To Wind the tubes as rolls in order as per operation guide
. |
|
Product Final Inspeciton
 |
 |
Visual check on the finished tube surface, it should appear gold color, smooth without scratch, water mark, electric nicks and fingerprints
. |
|
 |
Ensue the diameter of the finished tube within the stipulated tolerance by measuring
. |
|
 |
No cracks should be found during the end expanding test executed according to the operation guide
. |
|
 |
The specimen should not be broken during the flat test stated by the operation guide
. |
|
 |
The elongation, tensile strength and yield strength tests are made as per operation guide and all the resulted values should be in the stated range
. |
|
 |
The polished specimens of the tube section are observed under the metallographic microscope to check the overlap length, welding-line height and width
. |
|
 |
The inner clearness check is executed as per operation guide. The result impurity should be lower than 0.2 gram/ . |
|
|
| |
|
ΘΥ±ΎΣο 
English 
Deutsch
