1 main use
6~80mm thick a709 series high weathering bridge structural steel plates include a709gr50wa, a709gr50wb, a709gr50wc, a709gr50waf, a709gr50wbf, a709gr50wcf, a709hps50w, a709hps70w and so on. such steels are alloyed by cu, p, cr, ni, etc., forming a protective layer on the surface of the metal substrate, thereby having high atmospheric corrosion resistance. this type of steel is widely used in various weather-resistant building structural parts (especially for industrial atmospheric environments) and bridge auxiliary structural parts.
2 grades and standards
grades: a709gr50wa, a709gr50wb, a709gr50wc, a709gr50waf, a709gr50wbf, a709gr50wcf, a709hps50w, a709hps70w
executive standard: a709/a709m-04a
3 technical conditions of supply
3.1 product specifications:
6~100×1800~3800×l
3.2 chemical composition
table 1 chemical composition, %
牌号 | c | si | mn | p | s | cr | v | ni | cu |
a709gr50wa a709gr50waf | ≤0.19 | 0.30-0.65 | 0.80- 1.25 | 0.040 | 0.050 | 0.40-0.65 | 0.01-0.10 | ≤0.50 | 0.25-0.40 |
a709gr50wb a709gr50wbf | ≤0.20 | 0.15-0.50 | 0.75- 1.35 | 0.040 | 0.050 | 0.40-0.70 | 0.01-0.10 | ≤0.50 | 0.20-0.40 |
a709gr50wc a709gr50wcf | ≤0.15 | 0.15-0.40 | 0.80- 1.35 | 0.040 | 0.050 | 0.30-0.50 | 0.01-0.10 | 0.25-0.50 | 0.20-0.50 |
牌号 | c | si | mn | p | s | cu | cr | ni | mo | v | nb | al | n |
a709hps50w | ≤0.11 | 0.30~0.50 | 1.10~1.35 | ≤0.020 | ≤0.006 | 0.25~0.40 | 0.45~0.70 | 0.25~0.40 | 0.02~0.08 | 0.04~0.08 | / | 0.010~0.040 | ≤0.015 |
a709hps70w | ≤0.11 | 0.30~0.50 | 1.10~1.35 | ≤0.020 | ≤0.006 | 0.25~0.40 | 0.45~0.70 | 0.25~0.40 | 0.02~0.08 | 0.04~0.08 | / | 0.010~0.040 | ≤0.015 |
3.3 mechanical properties
table 2 mechanical properties
牌号 | σs, mpa, ≥ | σb, mpa | δ50,% |
a709gr50wa、a709gr50waf a709gr50wb、a709gr50wbf a709gr50wc、a709gr50wcf | ≥345 | ≥485 | ≥19 |
a709hps70w | 485 | 585-760 | 17 |
a709hps100w | 690 | 760-895 | 16 |
note: 1. charpy v-type impact test should be carried out according to customer requirements.
3.4 delivery status: hot rolled or normalized.