고온 특성 스테인리스 스틸

Stainless steel have good strength and good resistance to corrosion and 산화 at elevated temperatures. Stainless steel are used at temperatures up to 1700° F for 304 and 316 and up to 2000 F for the high temperature stainless grade 309(S) and up to 2100° F for 310(S). Stainless steel is used extensively in 열교환기, super-heaters, 보일러, feed water heaters, valves and main steam lines as well as aircraft and aerospace applications.

Figure 1 gives a broad concept of the hot strength advantages of stainless steel in comparison to low carbon unalloyed steel. Table 1 shows the short term 인장 강도 그리고 항복 강도 vs temperature. Table 2 shows the generally accepted temperatures for both intermittent and continuous service.

With time and temperature, changes in metallurgical structure can be expected with any metal. In stainless steel, the changes can be softening, carbide 강수량, or embrittlement. Softening or loss of strength occurs in the 300 series (304, 316, etc.) stainless steel at about 1000° F and at about 900° F for the hardenable 400 (410<, 420, 440) series and 800° F for the non-hardenable 400 (409, 430) series (refer to Table 1).

카바이드 강수량 can occur in the 300 series in the temperature range 800 – 1600° F. It can be deterred by choosing a grade designed to prevent carbide precipitation i.e., 347 (Cb added) or 321 (티타늄 added). If carbide precipitation does occur, it can be removed by heating above 1900° and cooling quickly.

Hardenable 400 series with greater than 12% chromium as well as the non-hardenable 400 series and the 듀플렉스 스테인리스 스틸 are subject to embrittlement when exposed to temperature of 700 – 950° F over an extended period of time. This is sometimes call 885F embrittlement because this is the temperature at which the embrittlement is the most rapid. 885F embrittlement results in low ductility and increased 경도 그리고 인장 강도 at room temperature, but retains its desirable 기계적 특성 at operating temperatures.

Table 1 Short Term 인장 강도 vs 온도 (410을 제외한 어닐링 상태)

* 열처리 by oil quenching from 1800° F and tempering at 1200° F

Table 2 Generally Accepted Service 온도

It may seem to be illogical that the “continuous” service temperature would be higher than the “intermittent” service temperature for the 300 series grades. The answer is that intermittent service involves “thermal cycling”, which can cause the high temperature scale formed to crack and spall. This occurs because of the difference in the coefficient of expansion between the stainless steel and the scale. As a result of this scaling and cracking, there is a greater deterioration of the 표면 than will occur if the temperature is continuous. Therefore the suggested intermittent service temperatures are lower. This is not the case for the 400 series (both ferritic and martensitic grades). The reason for this is not known.

관련 참고 자료:
고온 조건에서 스테인리스 스틸 사용 표 참조
부식 방지 스테인리스 스틸 튜브
스테인리스 스틸 튜브의 내식성
금속 강도에 대한 온도 영향
고온 스테인리스 스틸 튜브
고온 스테인리스 스틸 튜브
고온 특성 스테인리스 스틸
내열 스테인리스 스틸 튜브
용접 스테인리스 스틸 파이프
U-벤드 스테인리스 스틸 튜브
열교환기 튜브
이중 스테인리스 스틸 튜브
보일러 튜브, 응축기 튜브
골판지 심리스 스테인리스 스틸 파이프 튜브
DIN 2391 이음매 없는 정밀 강관
EN 10305-1 E215 E235 E355 이음매 없는 정밀 강관 튜브 튜브
내산성 스테인리스 스틸 튜브
밝은 어닐링 스테인리스 스틸 튜브
고온 튜브 및 파이프 표준
고온 변화 스테인리스 스틸의 기술적 특성
내열 스테인리스강 및 내식성 스테인리스강-밸브강, 철 베이즈 슈퍼 합금
폭발성 가스 환경에서의 스파크 위험