Steel TRIP690 +ZE (Electrogalvanized)
Finish state
ASTM A1088 TRIP690
Thin, very uniform zinc layer applied without a thermal cycle — keeps the as-annealed TRIP mechanical properties and gives the best surface for visible panels.
Values for the +ZE condition
Other TRIP690 tempers and conditions
TRIP690 is listed in 6 conditions; see the grade overview at TRIP690.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Thicker gauges (≈2–6 mm) for chassis arms, wheel discs and suspension parts where cold-rolled thickness is insufficient. | 440 | 710 | 24 | 15 HRC | 8 % IACS |
Hot-dip galvanized | Most common automotive supply form: zinc-coated for cathodic corrosion protection of exposed structural stampings. | 445 | 715 | 25 | 17 HRC | 8 % IACS |
CRDefault Cold rolled | Standard uncoated cold-rolled TRIP690 coil/blank for painted or later-coated stampings and for laboratory formability work. | 450 | 720 | 26 | 210 HB | — |
+ZEThis page Electrogalvanized | Thin, very uniform zinc layer applied without a thermal cycle — keeps the as-annealed TRIP mechanical properties and gives the best surface for visible panels. | 450 | 720 | 26 | 17 HRC | 8 % IACS |
Galvannealed | Choose when paint adhesion and spot-weldability of the coating matter more than maximum coating ductility (Zn-Fe layer powders on severe draws). | 455 | 720 | 24 | 17 HRC | 8 % IACS |
2 % pre-strained + paint-bake | In-service condition of a formed and painted part — work hardening plus bake hardening raise the yield strength markedly above the as-delivered value. | 580 | 760 | 20 | 20 HRC | 8 % IACS |
What is TRIP690 +ZE?
TRIP690 +ZE is TRIP690 supplied in the +ZE condition — thin, very uniform zinc layer applied without a thermal cycle — keeps the as-annealed TRIP mechanical properties and gives the best surface for visible panels. TRIP690 +ZE has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi). TRIP690 +ZE has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,425°C (2,597 °F). CR is the default condition FabDigit quotes; +ZE is available on request or by drawing note.
Advantages
- Good corrosion resistance — 33/100, better than 97% of steel grades
- Forms and bends easily — 80/100, better than 93% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to machine — 34/100, worse than 86% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
TRIP690 +ZE properties
Typical room-temperature values for TRIP690 +ZE; 23 are specific to this condition. Other listed values are TRIP690 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
TRIP690 +ZE has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
TRIP690 +ZE has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
TRIP690 +ZE is rated for continuous service to 200°C (392 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
TRIP690 +ZE conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), better than 97% of steel grades.
Sustainability4
Producing a kilogram of TRIP690 +ZE takes about 31 MJ of energy and emits 2.4 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability7
TRIP690 +ZE's machinability is poor (34/100, worse than 86% of steel grades); weldability good (62/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TRIP690 +ZE
Is TRIP690 easy to machine?
Rarely machined as sheet — trim, pierce and laser cut instead; use carbide tooling with generous clearance and expect high blanking loads (~2× mild steel) and rapid punch wear.
Can TRIP690 be welded?
Resistance spot welding is standard but needs a narrowed current window, higher electrode force and a post-weld tempering/downslope pulse to avoid brittle martensitic nuggets; laser welding gives good results with controlled carbon equivalent (CE ≈ 0.40–0.50).
Can TRIP690 be formed, bent or molded?
Very high n-value gives excellent stretch and deep-draw behaviour, but the TRIP effect raises forming loads and springback — plan 10–25 % more press tonnage than mild steel, use compensated dies and avoid excessive edge stretching (hole expansion is modest).
What surface finishes work on TRIP690?
Supply as +Z/+ZF/+ZE for corrosion protection; bare product must be phosphated and e-coated quickly, and high-Si grades need careful pickling/annealing atmosphere control for coating adhesion.
TRIP690 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ccarbon enriches and stabilises retained austenite | 0.15 – 0.25 | 0.2 |
| SiSi-alloyed variant; suppresses carbide precipitation in bainite | 0.2 – 2 | 1.4 |
| Mn | 1.2 – 2.2 | 1.6 |
| AlAl partly replaces Si in galvanizable Al-TRIP variants | 0.02 – 2 | 0.5 |
| P | ≤ 0.12 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Nboptional micro-alloying for grain refinement | ≤ 0.06 | 0.03 |
| Tioptional | ≤ 0.06 | 0.02 |
| Cr+Mooptional hardenability additions | ≤ 0.6 | 0.1 |
| N | ≤ 0.01 | 0.01 |
| Fe | balance | — |
TRIP690 +ZE — frequently asked
What is TRIP690 +ZE used for?
TRIP690 +ZE is typically used for cross members, longitudinal rails and wheel discs. In short: strong strength-elongation balance; deep-draw capable AHSS; mid-range TRIP workhorse.
What is the yield strength of TRIP690 +ZE?
TRIP690 +ZE has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is TRIP690 +ZE easy to machine?
Not especially — machinability is rated poor (34/100, worse than 86% of steel grades). Rarely machined as sheet — trim, pierce and laser cut instead; use carbide tooling with generous clearance and expect high blanking loads (~2× mild steel) and rapid punch wear.
Can TRIP690 +ZE be welded?
Yes — weldability is rated good (62/100). Resistance spot welding is standard but needs a narrowed current window, higher electrode force and a post-weld tempering/downslope pulse to avoid brittle martensitic nuggets; laser welding gives good results with controlled carbon equivalent (CE ≈ 0.40–0.50).
What surface finishes work on TRIP690 +ZE?
Supply as +Z/+ZF/+ZE for corrosion protection; bare product must be phosphated and e-coated quickly, and high-Si grades need careful pickling/annealing atmosphere control for coating adhesion.
Can TRIP690 +ZE be formed, bent or molded?
Very high n-value gives excellent stretch and deep-draw behaviour, but the TRIP effect raises forming loads and springback — plan 10–25 % more press tonnage than mild steel, use compensated dies and avoid excessive edge stretching (hole expansion is modest).
What is the maximum service temperature of TRIP690 +ZE?
TRIP690 +ZE is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between TRIP690-CR and TRIP690-BH?
CR is the default condition — standard uncoated cold-rolled TRIP690 coil/blank for painted or later-coated stampings and for laboratory formability work. BH: in-service condition of a formed and painted part — work hardening plus bake hardening raise the yield strength markedly above the as-delivered value. Yield strength is 450 MPa in CR versus 580 MPa in BH.
Sources
- EN 10346 — Continuously hot-dip coated steel flat products (HCT690T) — CEN (2015)
- VDA 239-100 — Sheet Steel for Cold Forming (CR440Y690T-TR) — VDA (2016)
- SAE J2745 / A1088 High Strength Steel Sheet designations — SAE / AISI (2019)
- Advanced High-Strength Steels Application Guidelines v7 — WorldAutoSteel (2021)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Automotive TRIP 690 cold rolled / galvanized product data — ArcelorMittal / Baosteel (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.