Does Pre-heating requires for SS400 steel grades?

Date 11-07-2011 06:30

I can't say for sure, but I would expect the higher carbon 4xx grades to need pre-heating, and if high enough carbon post-heating as well.

By Mark Anthony Nofuente (*)

Date 11-07-2011 09:00

We're having a project for a steel mill which most of the bracing and connecting members are SS400 grades but the main structures will be ASTM A572.

In most cases, higher thickness will only be used, such as 40 to 75mm which was SS400 grades.

In AWS D1.1, it is mentioning only for ASTM A6 standards and most of it I guess was only for high strength class which requires pre-heating prior welding while SS400 was a Japanese standard and it is a mild steel.

Though we may go for Carbon Equivalent calculation to verify if it necessary to conduct pre-heating but was it necessary, since the client itself are not well informed of this.

Thanks.

By DaveBoyer (*****)

Date 11-08-2011 03:28 Edited 11-08-2011 03:30

I thought You rere refering to the 4xx stainless steels We use in the US. These ar commonly called the 400 series.
Some of these with higher carbon respond to heat treatment.

The information from "ozniek" Niekie is more likely to be what You are looking for.

By ozniek

Date 11-07-2011 12:08

Hi Mark

JIS G3101 SS400 is equivalent to ASTM A36 steel, so anything the code recommends / requires for A36 (Category B) will also be applicable for SS400. This means pre-heats of 65°C are required once you go above 65mm, and increase in temperature the thicker you go. (I am assuming that you are using AWS D1.1 code, based on other posts.) Just make sure that everyone is happy with the way that the "Unlisted" material is being handled from a code point of view. Different clients / inspectors / engineers will deal with this differently. (In terms of WPS requirements etc.) Some will deal with it as being equivalent to A36, while other will insist that it is dealt with as an unlisted material requiring a lot more testing etc. - Best to get an agreement on this up front, to prevent any surprises later on.

Hope this helps.

Regards
Niekie

By Mark Anthony Nofuente (*)

Date 11-08-2011 04:25

Thanks a lot for your clarification Niekie.

Yeah! it is better to prevent such disputes later on as what you said, different person who will do the inspection will basically have different interpretation as well.