SA515-70, A515-70 Boiler and Pressure Vessel Plate

SA515-70, A515-70 Boiler and Pressure Vessel Plate
STEELMAX Steel Story

보일러, 압력용기용 탄소강판 규격으로
중, 고온용으로 사용됩니다.

SA515 Standard Specification for Pressure Vessel Plates,
Carbon Steel, for intermediate- and Higher-Temperature Service입니다.

AS515/A515에는 3가지 Grade가 있어
SA515-60 (415), SA515-65 (450), SA515-70 (485)입니다.

Killed steel로 제조 되며, 수요자 공급자간 협의에 의해
Fine grain or Coarse grain 으로 공급됩니다.

※ Fine grained steel (세립강 細粒鋼) : Steel with an austenitic
grain size number is 5 or over.
※ Coarse grained steel (조립강 粗粒鋼) : Steel with austenitic
grain size number is up to 5.

열처리로는 Normalized or Stress Relieved,
As rolled (압연 그대로) 로도 공급됩니다.

※ Stress Relieving (old name : stress relief annealing)
Every piece of steel has an amount of internal stress caused
by steel production, machining, surface finish, heat treatment
and other processes.
During a heat treatment process the yield strength is reduced
to a lower level. If precision parts or complicated tools with
close tolerances, this deformation could cause problems.
In the case after rough machining and stress relieving is done
with a high degree of machining allowance.
After this process the internal stress is reduced by the parts deforming.
The standard process is slow heating up to 550~650℃,
holding for minimum 2 hours and finishing with a slow cooling in the furnace.

모든 철강재는 생산, 가공, 표면 마무리, 열처리와 기타 공정 진행에서
내부 응력이 어느 정도 쌓일 수 밖에 없고, 이런 내부 응력을 해소 시키려고
적당한 온도로 가열하고 균열화한 후, 적절한 온도로 냉각함으로써
실질적인 조직의 변화 없이 내부 응력을 줄이고자 시행하는 열처리를 말합니다.

※ Killed Steel
Steel sufficiently deoxidized with ferrosilicon, aluminium, and so on.
In the case of ingot casting, during the progress of solidification in a ingot mold,
it is gently solidified without generation of carbon monoxide,
being comparatively uniform, with little segregation and has no blow hole.
however, because of a shrinkage cavity is formed in the centre of upper part,
its yield is low, In the case of continuous casting, it is killed steel and,
comparing with an ingot casting, uniformity and yield better.
killed steel is further classified according to grain size or deoxidizer.

페로실리콘이나, 알루미늄 등으로 충분히 탈산한 강철로,
용탕이 응고 진행 중에 일산화탄소를 발생 시키지 않고,
조용히 응고해, 비교적 균질하고, 편석이 적고, 기포도 없지만
응고된 강괴 윗부분 중심으로부터, 수축공이 생겨, 회수율이
좋지 못한 단점이 있고, 결정입도, 탈산제에 따라 세부적으로 더 분류됩니다.

※ Fine Grain Steel
Steels which resist grain growth over a considerable temperature range,
when held at temperature for a reasonable length
of time as is customary in heat treatment of steel.

SA515-70, A515-70 Boiler, Pressure Vessel, 강판