Annex 2-1 Guidance for seamless forged steel drums

1. Seamless forged steel drums

1.1 Application

(1) This requirements apply to seamless forged steel (hereinafter referred to as “forged drums”).

drums intended for boiler construction

(2) Items differing from those specified in this Guidance are to comply with the requirements in Pt 2, Ch 1, Sec. 1 and 2 of the Rules.

1.2 Kind

The forged drums are classified into grades as given in Table 1.

Table 1 Kind

1.3 Mechanical properties

The forged drums are to comply with the following requirements.

(1) Tensile test

The forged drums are to conform to the requirements given by Table 2 in the tensile test.

Table 2 Tensile Test

(2) Bend test

The test specimen is to stand being bent cold through l80 degrees without cracking outside to the inside radius given in Table 3.

Table 3 Bend Inside Radius

1.4 Selection of test specimens

(1) One set specimens each for tensile test and bend test are to be taken from each end of the forged drum, perpendicular to the centreline of the forged drum as well as opposite side each other with the centreline.

(2) Only in the case where ends of the forged drums are closed by reforging after machining, the test coupon may be cut from the forged drum before the reforging and heat treated simulta- neously with the forged drum. In such a case, the forged drum is to be heat treated again after reforging. The latter heat treatment is to be annealing at a temperature above the critical tem-

perature but not above the temperature of the first annealing when the former heat treatment is annealing, and to be same treatment as the former when the former heat treatment is normaliz-

ing and tempering.

48 Guidance Relating to the Rules for the Classification of Steel Ships 2015