ASME sec.8 head heat treatment 요구사항

UCS-79 FORMING PRESSURE PARTS

(d) Except when made of P-No. 1, Group Nos. 1 and 2; and P-No. 15E materials, all vessel shell sections, heads,

and other pressure parts fabricated by cold forming shall be heat treated subsequently (see UCS-56) when the resulting

extreme fiber elongation exceeds 5% from the supplied condition. For P-No. 1, Group Nos. 1 and 2, this

subsequent heat treatment is required when the extreme fiber elongation exceeds 40%, or if the extreme fiber elongation

exceeds 5% and any of the following conditions exist:

(1) The vessel will contain lethal substances either liquid or gaseous (see UW-2).

(2) The material is not exempt from impact testing by the rules of this Division or impact testing is required by

the material specification.

(3) The thickness of the part before cold forming exceeds 5/8 in. (16 mm).

(4) The reduction by cold forming from the as‐rolled thickness is more than 10% at any location where the extreme

fiber elongation exceeds 5%.

(5) The temperature of the material during forming is in the range of 250°F to 900°F (120°C to 480°C).

The extreme fiber elongation shall be determined by the equations in Table UG-79-1.

       * Carbon Steel

         . 냉간 성형된 탄소강 및 저합금강은 경판, 동체 및 다른 압력부는 압연된 조건으로

           부터 섬유질 연신율(Fiber Elongation)이 5% 이상이고 다음 5가지 조건의 하나일때

           열처리 되어야 한다.

           a. 내용물이 액체 또는 기체성의 독극물일 때

           b. 자재가 충격시험이 요구될 때

           c. 성형전 두께가 16㎜ 이상일 때

           d. 성형두께 감소율이 10% 이상일 때

           e. 성형중 자재의 온도가 120℃~480℃ 범위일 때

         . 상기 5가지 조건에서 제외된다 해도 Fiber Elongation이 40% 이상일때 열처리되어야 한다.