Previous study indicated that the composite of disodium hydrogen phosphate dodecahydrate and sodium sulfate decahydrate at Na2HPO4 center dot 12H(2)O: Na2SO4 center dot 10H(2)O = 9:1 (labeled as B-2) exhibits excellent properties as phase change material with supercooling of 4.8 degrees C and crystallization temperature of 28.2 degrees C. In this paper, sodium silicate nonahydrate (Na2SiO3 center dot 9H(2)O) is used as nucleating agent to add to B-2 to improve its properties further. It showed that the lowest supercooling of 3.4 degrees C could be obtained by addition of 3.25% Na2SiO3 center dot 9H(2)O to B-2, thus it produces a new optimal composite labeled as C (C = B-2 + 3.25% Na2SiO3 center dot 9H(2)O); the composite material C has stable thermal performance after 200 cycles with no phase separation. Furthermore, the corrosion of melt C to copper, stainless steel and aluminum is studied comparatively with melt B-2. It indicates that melt C has the least corrosion to aluminum due to the inhibition effect of Na2SiO3 center dot 9H(2)O, which differs from that of the corrosion behavior of melt B-2 significantly. Moreover, the effects of carboxymethyl cellulose (CMC) and sodium chromate tetrahydrate (Na2CrO4 center dot 4H(2)O) additions to C and B-2 are studied comparatively. Experimental results present that (a) addition of 1% CMC to B-2 aggravates its corrosion to aluminum and copper, but no effect on stainless steel, (b) addition of 1% Na2CrO4 center dot 4H(2)O to B-2 induces a certain inhibition effect on copper and aluminum, but intensifies the corrosion on stainless steel (c) addition of 1% CMC or 1% Na2CrO4 center dot 4H(2)O to C improves the corrosion resistance of stainless steel; addition of CMC or Na2CrO4 center dot 4H(2)O to B-2 and C does not change their thermal characteristics, such as supercooling and phase separation, on the whole.