BAIJIAN - Third party testing organization
The weld seam is formed by melting and connecting the welding rod and the metal at the joint using the high temperature of the welding heat source. After the weld metal cools down、 the two welding components are connected as a whole. According to the shape of the weld metal and the different positions of the welded parts、 it can be divided into butt welds、 fillet welds、 plug welds、 and electric riveting welds. Butt welds are commonly used for splicing plates and steel sections; Fillet welds are often used for lap joints; Plug welds and electric riveting are less commonly used and are only considered to reduce the overlap length of the weldment
Weld grade requirements: Level 1 welds require ultrasonic testing of ' of each weld length'; Secondary welds require a spot check of '20% of each weld length' and ultrasonic testing of no less than 200mm. The first and second level welds are fully penetrated welds、 and defects such as surface pores、 slag inclusions、 crater cracks、 and arc scratches are not allowed; The tensile pressure、 bending resistance、 and shear strength of the first and second level welds are the same as those of the base metal
During fusion welding、 the ratio of the weld width (c) to the calculated weld thickness (s) on the cross-section of a single weld seam is called the weld seam forming coefficient、 which is c/s. When the weld seam forming coefficient is small、 a narrow and deep weld seam is formed. In the center of the weld seam、 due to regional segregation、 more impurities will accumulate and the resistance to thermal cracking is poor. Therefore、 the forming coefficient value cannot be too small. For example、 in automatic submerged arc welding、 the weld seam forming coefficient should be greater than 1.3、 The width of the weld seam should be at least 1.3 times the calculated thickness of the weld seam
Function of testing report:
1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report
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1. Telephone communication and confirmation of requirements
2. Recommend solutions and confirm quotations 3. Mail samples and arrange testing 4. Progress tracking and result feedback 5. Provide reports and after-sales service 6. If urgent or priority processing is requiredTesting and testing characteristics:
1. The testing industry is fully covered、 meeting different testing needs
2. Fully cover the laboratory and allocate localized testing nearby3. Engineers provide one-on-one services to make testing more accurate
4. Free initial testing、 with no testing fees charged
5. Self service order delivery for free on-site sampling
6. Short cycle、 low cost、 and attentive service 7. Possess authoritative qualifications such as CMA、 CNAS、 CAL、 etc 8. The testing report is authoritative and effective、 and is generally used in China