Martensitic precipitation hardening stainless steel SUS630. High strength, high hardness, good weldability and corrosion resistance. Has been a lot of promotion used in valves, shafts and chemical fiber industry and has a corrosion resistant high strength parts and other requirements. SUS630 stainless steel (Japanese grade) stainless steel: SUS630 feature added copper precipitation hardening steel types. For the manufacture of shafts, turbine parts. Martensite by precipitation hardening copper, niobium / columbium constructed of stainless steel, low carbon content, corrosion resistance and weldability than the general number of martensitic stainless steel, similar to the 18-8 stainless steel, a simple heat treatment process, the cutting is good, but more difficult to meet the deep cold. Microstructure: Organizing for the precipitation hardening. Use for the manufacture of high corrosion resistance, high strength parts, such as bearings category, turbine parts. 2 Physical properties of the chemical composition of carbon C: ≤0.07 Si Si: ≤1.00 Mn Mn: ≤1.00 sulfur S: ≤0.030 phosphorus P: ≤0.035 chromium Cr: 15.50 ~ 17.50 Ni-Ni: 3.00 ~ 5.00 Copper Cu: 3.00 ~ 5.00 SUS630 stainless steel SUS630 stainless steel Niobium Nb: 0.15 ~ 0.45 SUS630 alloy is precipitation, hardening, martensitic stainless steel, and the grade of high strength, hardness and anti-corrosion properties. After heat treatment, the mechanical properties of the product more perfect, can reach up to 1100-1300 mpa (160-190 ksi) of compressive strength. This level can not be used above 300 ℃ (570F) or under very low temperatures, its atmosphere and dilute acid or salt has good corrosion resistance, corrosion resistance and its 304 and 430 the same. Mechanical properties of tensile strength σb (MPa): 480 ℃ aging, ≥1310; 550 ℃ aging, ≥1060; 580 ℃ aging, ≥1000; 620 ℃ aging, ≥930 Conditions yield strength σ0.2 (MPa): 480 ℃ aging , ≥1180; 550 ℃ aging, ≥1000; 580 ℃ aging, ≥865; 620 ℃ aging, ≥725 Elongation δ5 (%): 480 ℃ aging, ≥10; 550 ℃ aging, ≥12; 580 ℃ aging, ≥13; 620 ℃ aging, ≥16 section shrinkage ψ (%): 480 ℃ aging, ≥40; 550 ℃ aging, ≥45; 580 ℃ aging, ≥45; 620 ℃ aging, ≥50 Hardness: solution, ≤ 363HB and ≤38HRC; 480 ℃ aging, ≥375HB and ≥40HRC; 550 ℃ aging, ≥331HB and ≥35HRC; 580 ℃ aging, ≥302HB and ≥31HRC; 620 ℃ aging, ≥277HB ≥28HRC heat treatment process and heat treatment specifications: 1 ) solid solution 1020 ~ 1060 ℃ rapid cooling; 2) 480 ℃ aging after solution treatment, 470 ~ 490 ℃ air cooling; 3) 550 ℃ aging after solution treatment, 540 ~ 560 ℃ air-cooled; 4) 580 ℃ aging after solution treatment, 570 ~ 590 ℃ air cooling; 5) 620 ℃ aging after solution treatment, 610 ~ 630 ℃ air cooling. Microstructure: Organizing for the precipitation hardening.