How to Weld AISI 1045 (EN C45) Material: Complete Guide here

What is AISI 1045 (C45) Steel material?

AISI 1045 is a medium-carbon steel that can be heat treated and hardened (generally available as normalized or hardened condition). It contains manganese, and carbon as main alloying elements. This steel grade is often used for axles, bolts, and connecting rods in automotive and machinery applications.

To weld AISI 1045 (C45) material, it is important to use the correct welding process and parameters.

AISI 1045 (C45) Steel Material Specification

The UNS Number of AISI 1045 is UNS G10450. It is a unclassified material as per ASME Section IX and AWS D1.1 and has no defined P-Number for welding.

AISI 1045 material specifications are:

  • AISI 1045
  • SAE 1045
  • ASTM A29, A510 and A568
  • EN 10083-2

AISI 1045(C45) Steel Equivalent Materials

AISI 1045 equivalent material are:

  • SAE 1045,
  • ASTM A289 Gr. 1043, A49, ASTM A568 Gr. 1043,
  • DIN 1.1201 (C45R),
  • Afnor C45 (XC48H1u) and
  • EN C45 (1.0503).

AISI 1045 (C45) Steel Chemical Properties

AISI 1045 (C45) is a carbon- manganese base medium carbon steel. the chemical properties of AISI 1045 (C45) are given in below table.

ElementWt. %
Carbon (C)0.36-0.45
Silicon (Si)0.10-0.40
Manganese (Mn)0.60-1.00
Sulphur (S)0.050
Phosphorus (P)0.050
Single values are maximum

AISI 1045 (C45) Steel Mechanical Properties

AISI 1045 is a medium tensile low hardenability carbon steel. It has good machinability and can be hardened by heat treatment. The following table give an overview of AISI 1045 mechanical properties.

Tensile Strength, MPa (Ksi)565 (82)
Yield Strength, MPa (Ksi)310 (45)
ElongationMin. 16%

AISI 1045 (C45) Steel Welding Procedure

AISI 1045 is a unalloyed medium carbon steel. This material can be welded by all processes applicable to carbon steel, and can be heat treated to produce a wide range of mechanical properties due to its high carbon content. In order to improve weldability, this material is often supplied in the normalized or controlled rolled condition.

The most common welding methods for AISI 1045 are Stick welding, MIG (metal inert gas) and TIG (tungsten inert gas) welding.

Welding Preheat and Interpass Temperature for AISI 1045 (C45) Material

In order to prevent cracking, preheating is often necessary when welding thicker sections of AISI 1045. The recommended preheat temperature is between 200°C-250°C (400°F-480°F) due to high carbon equivalent (C.E.) in the material.

Welding preheat should be maintained until the welding is completed. If Post weld heat treatment is not planned, cover the welded part under kaowool to allow slow cooling.

Post Weld Heat Treatment of AISI 1045 (C45) Steel

PWHT (Post Weld Heat Treatment) of AISI 1045 (C45) shall be carried out at 550°C to 660°C (1022°F to 1220°F). Holding time for PWHT depend on the material thickness and usually kept as 1 hours per inch of weld metal thickness.

Welding wire and rods for AISI 1045 Steel

AISI 1045 (C45) Steel can welded with stick welding, TIG welding and MIG welding. Welding electrodes of filler wires for welding of AISI 1045 (C45) are listed in the below table.

For normalized condition: E7018, E8018-D1, E9018-D1 (AWS A5.5 welding rod specification)

For Quench & Tempered condition: E8018-D1, E9018-D1, E10018-D2 (AWS A5.5 welding rod specification). (If strength need to match, use higher strength stick welding rod).

Stick Welding (SMAW) of AISI 1045 (C45) Steel

Stick Welding or Shielded Metal Arc Welding (SMAW) of AISI 1045 (C45) can be carried out using E7018, E8018-D1, E9018-D1, and E10018-D2.

The selection of rod depends on the strength level required. In case only joining is required, you can use E7018 and for strength purposes you can choose between E8018D1, E9018-D1 and E10018-D2 based on actual material strength and heat treatment conditions.

Preheat & interpass control is mandatory for welding.

TIG & MIG Welding of AISI 1045 (C45) Steel

TIG & MIG Welding of AISI 1045 (C45) Steel shall be carried out using ER70S-2, ER80S-D2, ER90S-D2, or ER100S-G in case of high strength material condition.

For TIG, MIG welding required for only joining of AISI 1045 (C45) you can use ER70S-2/ ER70S-6 filler wire rod. For weld required to match strength of base metal, welding using ER80S-D2, ER90S-D2, or ER100S-G is suggested.

Welding AISI 1045 (C45) Steel to 1018

AISI 1045 (C45) Steel to 1018 steel is carried out using E7018 stick welding rod or ER70S-2 TIG-MIG welding wire rod. Preheating of AISI 1045 (C45) material is must to avoid any weld cracking in HAZ of AISI 1045. Follow preheat temperature given earlier.

Welding AISI 1045 (C45) Steel to 4140

Welding AISI 1045 (C45) Steel to 4140 Steel can be carried out using E8018-B2, E8018-D1 or ER80S-B2/ ER80S-D2. The recommended preheat temperature is between 200°C-250°C (400°F-480°F) due to high carbon equivalent (C.E.) in both the materials.

Welding AISI 1045 (C45) Steel to ASTM A36 Mild Steel

AISI 1045 (C45) Steel to ASTM A36 Steel l welding is suggested to carry out using E7018 E7018 stick welding rod or ER70S-2 TIG-MIG welding wire rod. Preheating of AISI 1045 (C45) material is must to avoid any weld cracking in HAZ of AISI 1045. Follow preheat temperature given earlier.

Welding AISI 1045 (C45) Steel to AISI 1020

AISI 1045 (C45) Steel to AISI 1020 Steel welding is suggested to carry out using E7018 E7018 stick welding rod or ER70S-2 TIG-MIG welding wire rod. Preheating of AISI 1045 (C45) material is must to avoid any weld cracking in HAZ of AISI 1045.