Steel 30CrNiMo8 Nitrided

What is 30CrNiMo8 Nitrided?

30CrNiMo8 Nitrided is 30CrNiMo8 supplied in the Nitrided condition — add a 0.2–0.5 mm gas or plasma nitrided case over the quenched and tempered core for wear and fatigue life with very little distortion; the 58 HRC surface is effectively unmachinable. 30CrNiMo8 Nitrided has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 92% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi). 30CrNiMo8 Nitrided has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). Q&T is the default condition FabDigit quotes; Nitrided is available on request or by drawing note.

Typical room-temperature values for 30CrNiMo8 Nitrided — 10 properties are specific to this condition; the rest are grade-level values shared by every 30CrNiMo8 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other 30CrNiMo8 tempers and conditions

30CrNiMo8 is also supplied in 10 other conditions. The full side-by-side table is on the 30CrNiMo8 overview.

• Q&TDefaultMost common stock condition: oil quenched and high-temperature tempered in 40–100 mm sections for 1100–1300 MPa tensile with a balanced combination of strength and toughness.1,000 MPa yield · 38 HRC
• Q&T 40-44 HRCUse low-temperature tempering for small sections needing the highest strength and wear resistance; toughness drops to 9% elongation and temper-embrittlement ranges must be avoided.1,220 MPa yield · 42 HRC
• +QT 1250Specify for bar up to 40 mm delivered to the highest EN 10083-3 strength class (Rm 1250–1450 MPa, Re ≥1050 MPa) for high-stress bolts and shafts; machinability falls to 32.1,120 MPa yield · 42 HRC
• Q&T 36-40 HRCSpecify for heavily loaded transmission parts and high-strength bolts at 1080 MPa yield; cutting is already noticeably difficult, with machinability down to 34.1,080 MPa yield · 38 HRC
• NitridedAdd a 0.2–0.5 mm gas or plasma nitrided case over the quenched and tempered core for wear and fatigue life with very little distortion; the 58 HRC surface is effectively unmachinable.1,000 MPa yield · 58 HRC
• Q&T 32-36 HRCGeneral-purpose high-strength band after quenching and tempering — the usual hardness for shafts, gear blanks and connecting rods, giving 950 MPa yield with 13% elongation.950 MPa yield · 34 HRC
• +QT 1000Pick for heavy forgings and large-diameter bar of 100–160 mm (Rm 1000–1200 MPa, Re ≥800 MPa), balancing through-section hardenability against toughness.880 MPa yield · 35 HRC
• Q&T 28-32 HRCChoose this machining-friendly low hardness band of the quench-and-temper range for large die sets, flanges and parts that may need weld repair after rough machining.830 MPa yield · 30 HRC
• +QT 900Use these guaranteed values for very large forged sections of 160–250 mm (Rm 900–1100 MPa, Re ≥700 MPa): lower core strength but the best toughness of the quenched and tempered range.780 MPa yield · 31 HRC
• +NUse normalising as an intermediate step after forging to refine and homogenise the structure; it is rarely specified as the final delivery condition.620 MPa yield · 28 HRC
• +AOrder soft annealed (max 248 HB) as the easiest state for machining and cold forming; rough-machine first, then quench and temper the part to its final strength level.520 MPa yield · 225 HB

Working with 30CrNiMo8 Nitrided

30CrNiMo8 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

30CrNiMo8 Nitrided — frequently asked

Sources