Project Description
1.5432, designated as 42MnMo7 under DIN and equivalent to API 5CT Grade N80, is a low-alloy manganese-molybdenum quenched and tempered steel bar engineered for demanding oil and gas service. SHUNFU METAL supplies this grade in multiple bar forms with rigorous quality assurance at every production stage.
Introduction to 1.5432 / 42MnMo7
This Mn-Mo low-alloy steel originates from the German DIN system as a quenched and tempered engineering steel. Developed primarily for the petroleum sector, it serves as the base material for N80-grade OCTG — including downhole tubing, surface casing, and coupling stock — where yield strengths exceeding 552 MPa are mandatory. The carefully balanced chemistry of 0.38–0.45% carbon with 1.55–1.85% manganese and a molybdenum addition of 0.15–0.25% delivers the ideal combination of high strength, deep hardenability, and reliable toughness after quenching and tempering.
At SHUNFU METAL, 1.5432 bars are produced through a controlled electric arc furnace melting route followed by vacuum degassing to minimize non-metallic inclusions and ensure tight chemical homogeneity. Every heat undergoes optical emission spectrometry verification before dispatch. The material is then hot-rolled or forged to the ordered dimensions and subjected to full-length ultrasonic testing per ASTM A388 / EN 10308 to guarantee internal soundness.
Equivalent Grades of 1.5432
1.5432 originates from the German DIN system and has recognized equivalents in several international standards for oilfield applications. Its API counterpart N80 is the industry workhorse for medium-to-high strength OCTG in sweet (non-sour) wells.
| Standard | Designation | Remarks |
|---|---|---|
| DIN W-Nr. | 1.5432 | German Werkstoff number |
| DIN | 42MnMo7 | Quenched & tempered steel |
| EN | 42MnMo7 | Harmonized European designation |
| API 5CT | N80 (Type 1 / Type Q) | OCTG casing & tubing |
No direct ASTM, AMS, JIS, or GOST equivalents exist for this Mn-Mo chemistry; the closest Cr-Mo alternatives (e.g., AISI 4140 / 42CrMo4) differ in alloy design.
Oil & Gas Applications
1.5432 / N80 steel bars are machined and fabricated into critical downhole and surface components that must withstand high pressures, cyclic stresses, and aggressive wellbore conditions in non-sour service environments.
Production & injection strings
Surface & intermediate strings
Length-adjustment connectors
Threaded pipe connectors
Wellhead & Christmas tree
Downhole & surface pumps
API 6A flanged connections
Flange & structural fasteners
BHA weight members
Packer & hanger bodies
Crossovers & adapters
Rams, bonnets, bodies
Supply Range — 1.5432 Steel Bar
SHUNFU METAL maintains extensive inventory of 1.5432 bars and provides custom forging and rolling services backed by ISO 9001-certified quality management. All bars are supplied with full mill test certificates (EN 10204 3.1 or 3.2) documenting heat number, chemical analysis, mechanical test results, and NDT reports.
| Form | Process | Diameter / Thickness | Width | Length |
|---|---|---|---|---|
| Round Bar | Hot-Rolled | ⌀10–500 mm | — | 3000–12000 mm |
| Round Bar | Forged | ⌀100–1200 mm | — | 2000–8000 mm |
| Flat Bar | Hot-Rolled | 3–150 mm | 10–610 mm | 3000–12000 mm |
| Flat Bar | Forged | 50–500 mm | 100–1200 mm | 2000–6000 mm |
Non-standard sizes, square bars, hexagonal bars, and stepped shafts are available upon inquiry. SHUNFU METAL also offers rough machining, saw cutting, and heat treatment services per customer specification.
Chemical Composition of 1.5432
The chemical composition of 1.5432 conforms to DIN 42MnMo7 specification and the API 5CT N80 grade chemistry envelope. The manganese-molybdenum alloy design provides enhanced hardenability over plain carbon steels while maintaining cost efficiency compared to Cr-Mo grades.
| C | Si | Mn | P | S | Mo |
|---|---|---|---|---|---|
| 0.38–0.45 | 0.20–0.35 | 1.55–1.85 | ≤0.04 | ≤0.04 | 0.15–0.25 |
Values in weight percent (wt%). Iron (Fe) constitutes the balance. Microalloying elements V, Nb, or Ti ≤ 0.10% each may be present for grain refinement in N80-Q variants. SHUNFU METAL verifies all heats by optical emission spectrometry.
Mechanical Properties of 1.5432 / N80
In the quenched and tempered condition, 1.5432 achieves the mechanical properties required for N80-grade OCTG per API 5CT. Two delivery conditions are standard: N80-1 (normalized or normalized + tempered) and N80-Q (quenched + tempered), with N80-Q delivering superior toughness and property consistency. SHUNFU METAL applies controlled tempering at 550–680°C to achieve the specified strength-toughness balance.
| Property | N80-1 | N80-Q |
|---|---|---|
| Yield Strength (min) | 552 MPa (80 ksi) | 552 MPa (80 ksi) |
| Tensile Strength (min) | 689 MPa (100 ksi) | 689 MPa (100 ksi) |
| Elongation (min, in 2″) | 16% | 16% |
| Hardness | 235–285 HBW | 235–285 HBW |
| Y/T Ratio (typical) | 0.85–0.95 | 0.80–0.90 |
| Impact Toughness (0°C, typical) | 40–60 J | 50–70 J |
| Heat Treatment | Normalized ± tempered | Quenched + tempered |
| Microstructure | Ferrite-pearlite | Tempered martensite/bainite |
N80-Q is the engineer’s preference for critical and deep-well applications due to better toughness uniformity and a more favorable yield-to-tensile ratio. SHUNFU METAL performs tensile, impact, and hardness testing on each heat treatment lot per API 5CT requirements.