Welding procedures for different steel types

So far, the factors responsible for hydrogen-induced cracking have been described, the principles upon which safe welding procedures can be based have been outlined, and the information required before using a welding diagram has been listed. It is now possible to explain in this chapter the selection of safe welding procedures for different steel types. 

The latest revision of BS 5135 will probably be incorporated into a European Standard which, at the time of writing, has not been issued for public comment. Among the suggested modifications, which have yet to be agreed, the following are relevant to the present text  

Modifications to welding procedures for steels of low CE, as in the present text. 

A new CE scale (E), probably based on a maximum diffusible hydrogen level of 3ml/100g deposited metal. 

Welding procedures for scale E similar to those for scale D, but appropriate to a steel having a CE 0.02 higher. 

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In Chapter 2 the construction of graphs and nomograms for the selection of suitable welding procedures for different steel types was described, but before using the nomograms, which are given in detail later, it is necessary to know how to select values for ... 

Carbon steels are widely used in all types of manufacturing. The weldability of the different types (low, medium, and high) varies considerably. The preferred analysis range of the common elements found in carbon steels is shown in Table 24.13. Welding metals whose elements vary above or below the range usually calls for special welding procedures. 

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