NK E36/EH36 Shipbuilding Steel Plate
NK E36/EH36 (KE36) shipbuilding steel plate — overview
NK E36/EH36 is the −40 °C high-tensile hull plate at level 36. In ClassNK Part K it is KE36. Level 36 is the workhorse of Japanese shipbuilding; most hull girder plating on modern NK-classed bulkers and tankers is a 36 grade. It gives ReH ≥ 355 N/mm², Rm 490–630 N/mm² and A ≥ 21 %. The title uses the dual trade name (E36/EH36) because Japanese and Chinese buyers search for both forms, but the plate itself is stamped KE36.
Equivalent grades: ASTM A131 Grade EH36 · ABS EH36 · DNV NV E36 · LR EH36 · BV EH36 · CCS E36 / EH36 · KR RE36 · RINA EH36 · GB 712 Grade EH36.
In the ClassNK series the letter sets the test temperature (KA 0 °C, KD −20 °C, KE −40 °C, KF −60 °C) and the number sets the yield (32 → 315, 36 → 355, 40 → 390 N/mm²). KE36 is the E letter at level 36. Typical NK uses: upper-deck crack-arrest strakes, hatch coamings of large container ships and LNG/LPG carrier structure needing −40 °C.
SHH STEEL sources KE36 from Chinese mills that hold NK approval for high-tensile hull steel, with the NK survey at the mill. Stock is held in the common 36-level sizes and other sizes are rolled to order.
KE36 (E36/EH36) key data
| Item | NK E36/EH36 / KE36 |
|---|---|
| Governing rules | ClassNK Rules for the Survey and Construction of Steel Ships, Part K; IACS UR W11 high-tensile grade EH36 (Part K numbering UNCERTAIN) |
| Names | NK designation KE36; trade dual E36/EH36; IACS EH36 |
| Strength | ReH ≥ 355 N/mm², Rm 490–630 N/mm², A ≥ 21 % |
| Charpy V | −40 °C |
| Steelmaking | killed, fine-grain treated (Al, Nb, V or Ti) |
| Delivery condition | AR / CR / N / TM as permitted by thickness and grain refiner (QT where approved) |
| TMCP carbon equivalent | Ceq ≤ 0.38 % (t ≤ 50 mm), ≤ 0.40 % (50–100 mm), indicative UR W11 practice — confirm at mill approval |
| Thickness | up to 100 mm (UR W11 scope); beyond by agreement with ClassNK |
| Tolerance | IACS UR W13 as applied by ClassNK (UNCERTAIN class) |
| Documents | NK-endorsed mill certificate; EN 10204 3.1/3.2 |
Commonly traded KE36 runs 8–60 mm thick in 2000–3000 mm widths. Heavier plate depends on the mill’s NK approval range for the delivery condition.
KE36 chemical composition — heat and product analysis
| Element | Heat (ladle) analysis, % | Product (check) analysis, % | Remark |
|---|---|---|---|
| C | 0.18 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | AH/DH/EH column |
| Mn | 0.90–1.60 (AH ≤12.5 mm may be 0.70 min.) | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Si | 0.10–0.50 | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| P | 0.035 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| S | 0.035 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Al (acid-soluble) | 0.015 min. acid-soluble (or total Al per UR W11 fine-grain practice) | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | grain refiner |
| Nb | 0.02–0.05 when used singly | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | grain refiner / strengthening |
| V | 0.05–0.10 when used singly | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Ti | 0.02 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Cu | 0.35 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Cr | 0.20 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Ni | 0.40 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| Mo | 0.08 max. | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | |
| N | — | numeric tolerance not tabulated in ClassNK Part K – agree on order / mill certificate | no cap in A/D/E column |
| Nb+V+Ti | 0.12 max. (combined, when used together) | not applicable (calculated from heat analysis) | combined microalloy cap |
| Ceq (TM plate) | 0.38 / 0.40 max. (calculated) | not applicable (calculated from heat analysis) | for t ≤ 50 / 50–100 mm |
Product (check) analysis column: ClassNK Part K specify heat (ladle) limits; no numeric product-analysis tolerance is tabulated in the rule text reviewed, so product (check) limits are agreed on the order or taken from the approved mill specification and certificate.
The ladle values follow IACS UR W11 for high-tensile hull steel, which ClassNK adopts in Part K (not checked against a Part K edition — UNCERTAIN). For KE grades, mills usually add Nb–Ti microalloying and keep sulphur well below the cap to secure −40 °C toughness in thick plate. For TMCP plate, ask for Ceq (and Pcm if your welding procedure uses it) on the certificate. Product analysis tolerances are agreed case by case.
KE36 tensile requirements
| Property | Value |
|---|---|
| ReH | 355 N/mm² min. |
| Rm | 490–630 N/mm² |
| A (5.65√S0) | 21 % min. |
| Charpy temperature | −40 °C |
Flat 200 mm test pieces: minimum elongation by thickness
| t (mm) | ≤5 | 5–10 | 10–15 | 15–20 | 20–25 | 25–30 | 30–40 | 40–50 |
|---|---|---|---|---|---|---|---|---|
| A200 min. % | 13 | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
KA36, KD36, KE36 and KF36 share these values. Only the Charpy temperature and, for KF, the chemistry differ.
KE36: Charpy at −40 °C and delivery condition
| Thickness | Avg. long. (J) | Avg. trans. (J) |
|---|---|---|
| ≤ 50 mm | 34 | 24 |
| 50–70 mm | 41 | 27 |
| 70–100 mm | 50 | 34 |
Required energy rises with thickness. A 70 mm KE36 plate must reach 50 J longitudinal at −40 °C, against 34 J for plate up to 50 mm. The delivery condition (AR, CR, N or TM) affects batch size and test frequency. Most Chinese mills now supply TM plate for this grade, which also helps Ceq.
Thickness tolerance and surface quality
Minus tolerance follows IACS UR W13 as ClassNK applies it. Plus tolerance, flatness and dimensions follow the agreed standard (JIS G3193, EN 10029 or GB/T 709). Weight-optimised high-tensile designs leave less margin, so check thickness at several points on receipt.
KE36 stock and lead time
| Thickness (mm) | Width (mm) | Length (mm) | Condition | Approx. qty |
|---|---|---|---|---|
| 6 | 1800 / 2000 | 6000–12000 | AR / N / TM | 100+ t |
| 8 | 2000 | 6000–12000 | AR / N / TM | 150+ t |
| 10 | 2000 / 2200 | 6000–12000 | AR / N / TM | 200+ t |
| 12 | 2000 / 2500 | 6000–12000 | AR / N / TM | 200+ t |
| 16 | 2200 / 2500 | 6000–12000 | AR / N / TM | 150+ t |
| 20 | 2500 | 6000–12000 | AR / N / TM | 120+ t |
| 25 | 2500 | 6000–12000 | AR / N / TM | 100+ t |
| 30 | 2200 / 2500 | 6000–12000 | AR / N / TM | 80+ t |
| 40 | 2200 | 6000–12000 | AR / N / TM | 50+ t |
| 50 | 2200 | 6000–12000 | AR / N / TM | 30+ t |
Stock quantities change every week, so confirm before you book. Plates are sold as KE36 with the NK stamp and endorsed certificate. Sizes not in stock are rolled in about 4–6 weeks including survey.
Packing: bundled by size with steel strapping, painted with grade and heat number, shipped in containers (≤11.8 m) or break bulk.
NK E36/EH36 (KE36) compared with other societies
| Society / standard | Grade | Note |
|---|---|---|
| ClassNK | NK E36/EH36 / KE36 | this page |
| DNV | DNV VL E36 | |
| LR | LR EH36 | |
| BV | BV EH36 | |
| CCS | CCS E36 / EH36 | |
| KR | KR RE36 | |
| ABS | ABS EH36 | |
| RINA | RINA EH36 (designation per RINA rules) | no product page yet |
| ASTM A131 | ASTM A131/A131M Grade EH36 | product standard only |
| GB 712 | GB 712 Grade EH36 | product standard only |
All share the UR W11 EH36 requirements. Each society accepts only its own stamp, so dual certification must be booked before the plates are tested.
Choosing KE36 within the ClassNK high-tensile series
Read across for toughness (KA36 → KD36 → KE36 → KF36) and down for strength (KE32 → KE36 → KE40). ClassNK’s material-grade table fixes the letter from member category and thickness. The designer fixes the number from the scantlings. Substituting a higher letter of the same number is normally accepted; a lower letter is not.
Above 390 N/mm², ClassNK’s extra-high-strength grades start at KA420 (IACS UR W16). See NK Steel Plates for the full series.
Using KE36 in the yard
Uses: upper-deck crack-arrest strakes, hatch coamings of large container ships and LNG/LPG carrier structure needing −40 °C. Welding: use high-tensile consumables approved by ClassNK for −40 °C toughness (grade 4Y or higher, typical — confirm in the WPS). Preheat and heat input come from the NK-approved procedure and the certificate Ceq. Large-heat-input electrogas or one-side SAW on thick KE36 needs a procedure qualified for that heat input.
Forming: TMCP plate gets part of its strength from controlled rolling. Keep line heating within the mill’s temperature limits, typically below about 650 °C for water cooling (UNCERTAIN, mill-specific).
NK survey, certificates and receiving checks
The certificate lists ladle chemistry including microalloys, Ceq for TM plate, tensile results, Charpy results at −40 °C, delivery condition and plate numbers, with the NK endorsement. We can add EN 10204 3.2 third-party witness, UT to EN 10160 or ASTM A578, Z-direction testing, and dual class with ABS, DNV, LR or BV.
On receipt: check the stamp reads KE36, Charpy results are at −40 °C for the right thickness band, and the NK endorsement is present.
Ordering errors seen with KE36
- Writing only “AH36” or “A36” without stating ClassNK, so the plate arrives with another society’s stamp
- Omitting the letter, so toughness is undefined
- Accepting mild-steel KA–KE certificates against a high-tensile order
- No Ceq on the certificate for TM plate
- Substituting KA36 without approval
- Charpy band for the delivered thickness not checked
Buying KE36 from China: concerns and answers
| Concern | Answer |
|---|---|
| Is the NK stamp genuine? | Only mills with ClassNK approval for KE36; certificate and stamp traceable to the heat; third-party witness on request |
| Payment safety | T/T with balance after inspection, or L/C at sight |
| Small or mixed orders | several sizes and NK grades in one container |
| Delivery visibility | weekly photos from rolling to loading |
| Ready-to-fit parts | cutting, bevelling and drilling in our own workshop |
Ordering KE36
State: NK E36/EH36 (KE36), delivery condition, sizes and quantities, UT/Z, dual-class, certificate type and port. Send to SHH STEEL.
Sample line: “Hull plate to ClassNK Rules Part K, grade KE36 (NK E36/EH36), TM, 25 × 2500 × 12000 mm, 20 pcs, NK-endorsed certificate with Ceq, EN 10204 3.2, CFR Busan/Imabari.”
FAQ
Conclusion
NK E36/EH36 (KE36) is ClassNK high-tensile hull steel under Part K of the Rules for the Survey and Construction of Steel Ships: yield 355 N/mm², tensile 490–630 N/mm², Charpy −40 °C. An NK-classed hull accepts it only with the NK stamp and an endorsed certificate.
SHH STEEL supplies KE36 from NK-approved Chinese mills, with cutting, dual class, UT and EN 10204 3.2 on request. Send grade, sizes, quantities and port for a quotation.