ISO 630-2:2011 pdf free download – Structural steels – Part 2: Technical delivery conditions for structural steels for general purposes.
3.4
thermomechanical processed
steel rolled with a process in which the final deformation is carried out in a certain temperature range leading to a material condition with certain properties which cannot be achieved or repeated by heat treatment alone
NOTE I Hot forming or post-weld heat treatment above 580 °C may lower the strength values and should not be performed. Flame straightening can be applied in accordance with relevant technical recommendations.
NOTE 2 Thermomechanical rolling can include processes with an increasing cooling rate with or without tempering, including self-tempering but excluding direct quenching and quenching and tempering.
NOTE 3 In some publications, the wording Thermomechanical Control Process” is also used.
4 Classification and designation
4.1 Classification
The steel grades specified in this part of ISO 630 shall be classified as non-alloy or alloy quality steels.
4.2 Grades and qualities
This part of ISO 630 specifies eight steel grades. Grades S235, S275, S355, and S450 are specified in Annex A. Grades 5G205, SG250, 5G295, and 5G345 are specified in Annex B. Each grade is available in up to four qualities. These grades and qualities differ in their specified mechanical properties and impact energy requirements.
Quality A: no impact testing.
Quality B: impact testing at 20 °C.
Quality C: impact testing at 0 °C.
Quality D: impact testing at 20 °C.
6 Requirements
See ISO 630-1.
6.1 Steel-making process
See ISO 630-1.
If a special steel-making process has been specified, this shall be reported in the inspection document.
6.2 Delivery condition
At the manufacturer’s discretion, the products covered by this part of ISO 630 are delivered in the as-rolled condition, normalized rolled, normalized, or thermomechanical processed condition. The delivery condition is indicated in the inspection document.
6.3 Chemical composition
6.3.1 Heat analysis
The chemical composition determined by heat analysis shall comply with the values specified in Table A.1 or Table B.1.
6.3.2 Product analysis tolerances
The product analysis of grades S235, S275, S355 and S450 shall comply with the values given in Table A.2.
The permitted deviations on analysis of grades SG205, 5G250, SG285 and SG345, relative to the values for heat analysis, are given in Table B.2.
6.3.3 Carbon-equivalent value
The carbon-equivalent value (CEV) requirements for the grades in Annex A are given in Table A.3.
6.7 Dimensions and tolerances on dimensions, shape and mass See ISO 630-1.
7 Inspection
Type of inspection documents (specific or non-specific) shall be specified. Refer to ISO 630-1:2011, 7.1.
8 Sampling Frequency of testing
8.1 Verification
The verification of mechanical properties shall be by heat. Verification by lot shall be by agreement between the producer and purchaser.
8.2 Test units
8.2.1 Annex A
The test unit shall contain products of the same form, grade, quality, and delivery condition, and of the same thickness range as specified in Table A.4 for the yield strength, and shall be:
— by heat: 40 tons or part thereof;
— 60 tons or part thereof for heavy sections with a mass> 100 kg/rn;
— 80 tons or part thereof for all sections if the mass of the heat exceeds 200 tons.
By agreement at the time of ordering, two tests by heat may be used.