Table of Contents

Automotive exhaust system steel – 436L stainless steel

436L stainless steel, grade: 00Cr17Mo, has a density of 7.75g/cm3, reduced carbon and nitrogen content, and added elements such as molybdenum and titanium to provide excellent corrosion resistance and formability. As a result, it is more resistant to stress corrosion than SUS304 in coastal atmospheric exterior decoration, pools, and other harsher corrosive environments. Because there is no need to add nickel, cheaper than 304 stainless steel, and the price fluctuation is smaller.

An automotive exhaust system is a key component of a vehicle’s engine that is responsible for managing the waste gases and fumes released from the combustion process. It consists of a series of pipes, converters, mufflers and resonators that direct these emissions away from the vehicle and into the atmosphere.

Automotive exhaust system special steel - 436L stainless steel

Chemical composition (%):

  1. Carbon C: ≤ 0.025
  2. Chromium Cr: 16~19
  3. Molybdenum Mo: 0.75~1.25
  4. Titanium Ti: 8 × (C% + N%) ~ 0.8
  5. Niobium Nb:8×(C%+N%)〜0.8

Mechanical properties:

  • Yield strength σ0.2 (MPa)≥245
  • Tensile strength σb (MPa)≥410
  • Elongation δ5 (%)≥20
  • Hardness: HB≤217; HRB≤96; HV≤230
  • Specific heat capacity (0~100℃, KJ-kg-1K-1): 0.46
  • Longitudinal modulus of elasticity (20℃, KN/mm2): 200
  • Thermal conductivity (W-m-1-K-1): (1000) 25
  • Coefficient of linear expansion (10-6-K-1): (200~1000℃) 10.4

Execution standard:

GB, AISI, KS, JIS

Surface condition:

Cold rolled annealed solid solution.

Corrosion resistance:

Increasing breakdown potential of 436L (00Cr17Mo) stainless steel with increasing Mo content.
436 (00Cr17Mo) pitting potential is comparable to that of SUS304 austenitic stainless steel.
The pitting resistance of 436L (00Cr17Mo) is better than 430 steel and close to 304.
436L (00Cr17Mo) is less rusty than 304.

good corrosion resistance in boiling solutions with concentrations below 20% NaOH
Hydrochloric acid and the sulfuric acid solution are not corrosion-resistant.