AWS D1.1 Equivalent steels ( China GB Q235B & Q345B)

By noirengineering Date 04-20-2017 04:31

Hello experts,

I have a situation where our fabricator in China using AWS D1.1 WPS & PQR . I am not a welding expert, so would appreciate advice on structural welding.

Is impact test mandatory and macro ecth test for PQR qualification as per AWS D1.1 & D1.6 ?

Which group the materials used ( Q235B & Q345B) would fit in according to AWS D1.1 material grouping?

Can pipes be covered with same WPS & PQR if it is of same material ?

Should there be a seperate WPS & PQR for each inter material welding ? i.e. Q235B to Q345B , SS316 to Q235B or SS316 to Q345B ? or can this material variations be captured in WQR using but same WPS & PQR ?

By 803056

Date 04-20-2017 12:00

Either the base metal specification is listed by an AWS structural welding code or it isn't. If it is listed, it is prequalified. If it isn't listed, it is not prequalified and can only be used if the procedure has been qualified for the specific material used in production.

The contractor must use the material specified by the approved contract (design) drawings unless the "Owner's" Engineer (as defined by the applicable welding code) approves the substitution. That allowance is for that project only and does not extend to other project for different Owners.

CVN is only required when it is specified by the project specification or design. The Owner's Engineer is required to specify the test temperature and the required test results.

In this case I would ask the customer, e.g., the Owner, if they are allowing the material substitution, assuming the Owner originally specified a material listed by the structural welding code. Just because the materials may have similar chemistries, it doesn't mean they have the same mechanical properties. That's why AWS structural welding codes do not include any AISI steels which are specified by chemistry only.

Al