Just to focus in the link of the excellent article Js55 posted and what Nantong so eloquently described regarding S460M, these excerpts "zero in" on just what is to be understood regarding this type of steel...
This is from the same article verbatim, "High Performance Steels in Europe - Production Processes, Mechanical and Chemical Properties, Fabrication Properties"
"By Anders SAMUELSSON & Falko SCHROTER" and can be found on pages 106 to 109 - Starting with 5.1.4 Fabrication Properties - 5.1.4. Welding, and continuing in to page 107 starting on the 2nd paragraph...
"Use a filler material with low hydrogen content... An example of preheating recommendations from One producer is given in Table 5.1.4...
The heat input determines the properties of the weld... Low beat input increases the maximum hardness and the risk tor cold cracking, whereas high beat input decreases
the toughness... Examples of recommendations are: For S420M, S460M up to 5.3 kJ/mm; for S690Q up to 3.5 kJ/mm, depending in both cases on the combined plate
thickness. For thinner combined thicknesses, below 60 to 80 mm, the heat input must be reduced..."
"On the choice of filler material: Choose a filler material giving a hydrogen content equal to or<10 ml/100 g...
For an S690 plate thicker than 20 mm,equal to or<5 ml/100g is recommended... Regarding S460M steels matching or overmatching (Filler) material can be chosen..."
They continue with some points regarding stress relieving until the last paragraph which gives a more realistic conclusion as to how often it's used & exceptions to normal use...
"Our general practical experience is that post weld heat treatment is not necessary... The toughness and hardness of the weldment normally meet the requirements
and is not substantially improved by stress relieving. It should only be carried out if a reduction of the residual stresses is needed for some special purpose or if
specified in the design codes."
"5.1.4.3 Cold Forming
General recommendations are found in ECSC IC 2 [5.3]... The material standards (EN 10025-4, -6) have a Note: "Cold forming in general leads to a reduction of the ductility... Furthermore it is necessary to draw attention to the risk of brittle fracture in connection with hot-dip zinc coating." For TM steels EN 10025-4 has options regarding
flangeability for material with a nominal thickness t equal to or < 12 mm and roll forming for material with t equal to or < 8 mm..."
"For the steel grades S420 and S460 the minimum bend radius is 4 times t with the axis of the bend in the transverse direction and 5 times t in the longitudinal direction...
For QT steels EN 10025-6 has an option regarding flangeability tor material with a nominal thickness t ~ 16 mm. For the S690 grade the minimum bend radius is 3.0 times t with the axis of the bend in the transverse direction and 4.0 times t in the longitudinal direction. Transverse and longitudinal refer to the rolling direction...
However, also in this respect the steels often have far better properties than specified in the standards. An example from one manufacturer is given in Table 5.1.5."
"5.1.4.4 Hot Forming
General recommendations are found in ECSC IC 2 [5.3]... According to EN 10025-4
TM steels shall not be hot formed (S460M)... If deemed necessary the manufacturer shall be consulted... Often forming at a maximum temperature of 580°C for short times is allowed... QT steels can be hot formed... EN 10025-6 permits hot forming up to the stress relief annealing temperature, normally in the range 550°C to 580°C... This agrees with the recommendations of the steel manufacturers... In practice hot forming is rarely used due to the good cold formability of these steels."
Once again, thanks for posting that link Js55!
Respectfully,
Henry
