Introduction to JIS G3458 Alloy Steel Boiler Tube Standard Specifications
The JIS G3458 standard outlines the specifications for heat-resistant alloy steel pipes used in high-temperature applications, such as heaters and boiler tubes. These pipes are designed to withstand extreme thermal conditions while maintaining structural integrity and durability over time.
Production Method:
| Grade |
Heat Treatment |
| STPA 12 |
Low temperature annealing, isothermal annealing, full annealing, normalizing, or normalization followed by tempering |
| STPA 20 |
| STPA 22 |
| STPA 23 |
Low temperature annealing, isothermal annealing, full annealing, or tempering after annealing |
| STPA 24 |
| STPA 25 |
| STPA 26 |
Isothermal annealing, full annealing, or normalization followed by tempering |
Chemical Composition:
| Grade |
Chemical Composition (%) |
| C |
Si |
Mn |
P |
S |
Cr |
Mo |
| STPA 12 |
0.10–0.20 |
0.10–0.50 |
0.30–0.80 |
≤0.035 |
≤0.035 |
- |
0.45–0.65 |
| STPA 20 |
0.10–0.20 |
0.10–0.50 |
0.30–0.60 |
≤0.035 |
≤0.035 |
0.50–0.80 |
0.45–0.65 |
| STPA 22 |
≤0.15 |
≤0.50 |
0.30–0.60 |
≤0.035 |
≤0.035 |
0.80–1.25 |
0.45–0.65 |
| STPA 23 |
≤0.15 |
0.50–1.00 |
0.30–0.60 |
≤0.030 |
≤0.030 |
1.00–1.50 |
0.45–0.65 |
| STPA 24 |
≤0.15 |
≤0.50 |
0.30–0.60 |
≤0.030 |
≤0.030 |
1.90–2.60 |
0.87–1.13 |
| STPA 25 |
≤0.15 |
≤0.50 |
0.30–0.60 |
≤0.030 |
≤0.030 |
4.00–6.00 |
0.45–0.65 |
| STPA 26 |
≤0.15 |
0.25–1.00 |
0.30–0.60 |
≤0.030 |
≤0.030 |
8.00–10.00 |
0.90–1.10 |
Mechanical Properties:
| Grade |
Mechanical Properties |
| Tensile Strength |
Yield Point or Proof Stress |
Elongation (%) |
| kgf/mm² {N/mm²} |
kgf/mm² {N/mm²} |
No. 11 or No. 12 Test Piece |
No. 5 Test Piece |
No. 4 Test Piece |
| Longitudinal |
Transverse |
Longitudinal |
Transverse |
| STPA 12 |
39 {382} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 20 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 22 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 23 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 24 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 25 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
| STPA 26 |
42 {412} min. |
21 {206} min. |
30 min. |
25 min. |
24 min. |
19 min. |
These specifications ensure that the materials meet the required performance levels under high-temperature conditions. The JIS G3458 standard is widely recognized in industries where reliability and safety are critical, such as power generation, petrochemicals, and industrial heating systems. By following these standards, manufacturers can produce boiler tubes that are both durable and efficient, contributing to the overall performance and longevity of the equipment they support.
Silicon Metal
Si Metal 441,metal silicon powder,Si metal slag,silicon metal 441
ANYANG TIEFA METALLURGY CO.,LTD , https://www.ferroalloytiefa.com