what is difference between c3 and c4 classification as per AWS 5.01?? any requirements is there like c3 need mechanical testing and c4 no need mechanical testing?
Material requirement are followed electrode spec. and/or supplementary requirement as agreed between manufacturer and purchaser.
We normally reviewed MTCs and found the different of covered electrode:
- MTC of carbon steel is most inspection type 3.1 for both of chemical composition and mechanical properties.
- MTC of stainless steel electrode is only inspection type 3.1 for chemical compositions, type 2.2 for mechanical properties.
You may find out at each specification as below:
Covered electrode classification as per AWS A5.1 - carbon steel
- 1 Type of current (see Table 1)
- 2 Type of covering (see Table 1)
- 3 Welding position (see Table 1)
- 4 Mechanical properties of the weld metal in the as-welded or aged condition (see Tables 2 and 3).
Covered electrode classification as per AWS A5.4 - stainless steel
- 1 Chemical composition requirements for undiluted weld metal (Table 1).
- 2 Type of welding current and position of welding (Table 2).
In additional, You’d like to verify covered electrode, you may prepare a test coupon per each lot.